Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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41662 Publications

Learning Electron Bunch Distribution along a FEL Beamline by Normalising Flows

Willmann, A.; Couperus Cabadağ, J. P.; Chang, Y.-Y.; Pausch, R.; Ghaith, A.; Debus, A.; Irman, A.; Bussmann, M.; Schramm, U.; Hoffmann, N.

Abstract

Understanding and control of Laser-driven Free Electron Lasers remain to be difficult problems that require highly intensive experimental and theoretical research. The gap between simulated and experimentally collected data might complicate studies and interpretation of obtained results. In this work we developed a deep learning based surrogate that could help to fill in this gap. We introduce a surrogate model based on normalising flows for conditional phase-space representation of electron clouds in a FEL beamline. Achieved results let us discuss further benefits and limitations in exploitability of the models to gain deeper understanding of fundamental processes within a beamline.

  • Poster
    Machine Learning and the Physical Sciences, 03.12.2022, the New Orleans Convention Center in New Orleans, USA
  • Open Access Logo Contribution to proceedings
    Machine Learning and the Physical Sciences workshop, 03.12.2022, New Orleans, USA

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Permalink: https://www.hzdr.de/publications/Publ-35958


Spectroscopy of XFEL heated Cu and x-ray absorption in laser-produced Warm Dense Cu

Smid, M.

Abstract

We report on a recent (Feb 2022) experiment on the spectroscopic characterization of XFEL-heated Cu foil targets. The 1-5μm thick Cu foils were irradiated by the tightly focused XFEL beam (~1μm focus, up till 1mJ in energy, European XFEL), heating the target to more then 100 eV, and clearly observing emission from ions up till Cu 25+. Three crystal spectrometers were measuring the emission and scattering in the range ~ 8000 - 9800 eV, i.e. covering the lines of Cu Kα and Kβ, including their ionized satellites. The XFEL photon energy was varied in the range 8.8-9.8 keV. The primary aim is to resolve the continuum lowering by checking the shifts of K edge for various ionizations, in a similar manner as was done earlier on lighter elements. Apart from this, many interesting phenomena can be studied from this extensive dataset, like the double-core hole (hollow ion) emission and its shift, resnonances, XRTS, and even Xanes absorption, by comparing the emission from the front and rear sides of the target. Having those data available in a well characterized system provides a high demand as well as benchmark for precise atomic simulations, and in general leads to a better understanding of Warm Dense Copper on the atomic physics level.

Involved research facilities

  • Draco
  • Lecture (Conference)
    Radiative Properties of Hot Dense Matter, 14.-18.11.2022, Santa Fe, United States of America

Permalink: https://www.hzdr.de/publications/Publ-35957


Combined Au/Ag nanoparticle creation in ZnO nanopillars by ion implantation for optical response modulation and photocatalysis

Macková, A.; Jagerová, A.; Lalik, O.; Mikšová, R.; Poustka, D.; Mistrík, J.; Holý, V.; Schutter, J. D.; Kentsch, U.; Marvan, P.; Azarov, A.; Galeckas, A.

Abstract

ZnO nanopillars were implanted with Au-400 keV and Ag-252 keV ions with ion fluences from 1 × 10¹⁵ cm⁻² to 1 × 10¹⁶ cm⁻². We compared ZnO nanopillars solely implanted with Au-ions and dually-implanted with Au and Ag-ions. Rutherford Back-Scattering spectrometry (RBS) confirmed Ag and Au embedded in ZnO nanopillar layers in a reasonable agreement with theoretical calculations. A decreasing thickness of the ZnO nanopillar layer was evidenced with the increasing ion implantation fluences. Spectroscopic Ellipsometry (SE) showed a decrease of refractive index in the nanopillar parts with embedded Au, Ag-ions. XRD discovered vertical domain size decreasing with the proceeding radiation damage accumulated in ZnO nanopillars which effect was preferably ascribed to Au-ions. SE and diffuse reflectance spectroscopy (DRS) showed optical activity of the created nanoparticles at wavelength range 500 – 600 nm and 430 – 700 nm for the Au-implanted and Au, Ag-implanted ZnO nanopillars, respectively. Photoluminescence (PL) features linked to ZnO deep level emission appear substantially enhanced due to plasmonic interaction with metal nanoparticles created by Ag, Au-implantation. Photocatalytic activity seems to be more influenced by the nanoparticles presented in the layer rather than the surface morphology. Dual implantation with Ag, Au-ions enhanced optical activity to a larger extent without significant morphology deterioration as compared to the solely Au-ion implanted nanopillars.

Keywords: ZnO nanopillars; Au/Ag nanoparticles; ion implantation; SPR; doped ZnO nanostructures

Involved research facilities

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Permalink: https://www.hzdr.de/publications/Publ-35956


Data publication: Energy relaxation and electron-phonon coupling in laser-excited metals

Zhang, J.; Qin, R.; Zhu, W.; Vorberger, J.

Abstract

DFT data and results for Al and Cu for the DOS, phonon DOS, and Eliashberg function depending on the electron temperature.

Keywords: electron-phonon; DFT; laser; laser-matter interaction; two-temperature model; relaxation; energy transfer

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Permalink: https://www.hzdr.de/publications/Publ-35955


Nonlinear dynamics of Dirac fermions in topological HgTe structures

Uaman Svetikova, T. A.; Pashkin, O.; de Oliveira, T.; Bayer, F.; Berger, C.; Fuerst, L.; Buhmann, H.; Molenkamp, L. W.; Helm, M.; Kiessling, T.; Winnerl, S.; Kovalev, S.; Astakhov, G.

Abstract

High harmonic generation (HHG) has applications in various fields, including ultrashort pulse measurements, material characterization and imaging microscopy. Strong THz nonlinearity and efficient third harmonic generation (THG) were demonstrated in graphene [1], therefore it is natural to assume the presence of the same effect in other Dirac materials, such as topological insulators (TI). Topological states can be found in HgTe quantum wells with a thickness of more than 6.3 nm [2], and strained 3D Hg1-xCdxTe thin films with cadmium fraction x < 0.16 [3].
We used a series of HgTe samples corresponding to three qualitatively different cases: 2D trivial and topological structures and 3D topological insulators. By using moderate THz fields, the presence of highly efficient THG was measured in these samples at different temperatures and THz powers. This provides insight into physical mechanisms leading to THG in TIs. For in-depth understanding of Dirac fermions dynamics and dominating scattering mechanisms in HgTe TI, we conducted THz pump-probe experiments that reveal several relaxation time scales.

[1] Hafez, H. A. et al., Nature 561, 507 (2018).
[2] Bernevig, B. et al. Science 314, 5806 (2006): 1757-1761.
[3] Brüne, C., et al. Phys. Rev. Lett. 106, 12 (2011): 126803.

Keywords: topological insulators; HgTe; nonlinear dynamics

Involved research facilities

  • F-ELBE
  • Lecture (Conference)
    3rd QMA retreat, 12.-14.10.2022, Friedrichroda, Deutschland
  • Poster
    DPG Meeting of the Condensed Matter Section (SKM): Regensburg 2022, 04.-09.09.2022, Regensburg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35954


Nonlinear parameters of Dirac fermions in HgTe structures: trivial and topological

Uaman Svetikova, T. A.; Pashkin, O.; de Oliveira, T.; Bayer, F.; Berger, C.; Fuerst, L.; Buhmann, H.; Molenkamp, L. W.; Helm, M.; Kiessling, T.; Winnerl, S.; Kovalev, S.; Astakhov, G.

Abstract

High harmonic generation (HHG) has applications in various fields, including ultrashort pulse measurements, material characterization and imaging microscopy. Strong THz nonlinearity and efficient third harmonic generation (THG) were demonstrated in graphene [1], therefore it is natural to assume the presence of the same effect in other Dirac materials, such as topological insulators (TI) [2,3]. Topological states can be found in HgTe quantum wells with a thickness of more than 6.3 nm [4], and strained 3D Hg1-xCdxTe thin films with cadmium fraction x < 0.16 [5]. We used a series of HgTe samples corresponding to three qualitatively different cases: 2D trivial and topological structures and 3D topological insulators. By using moderate THz fields, the presence of highly efficient THG was measured in these samples at different temperatures and THz powers. This provides insight into physical mechanisms leading to THG in TIs. For in-depth understanding of Dirac fermions dynamics and dominating scattering mechanisms in HgTe TI, we
conducted THz pump-probe experiments that reveal several relaxation time scales.

[1] Hafez, H. A. et al., Nature 561, 507 (2018).
[2] Kovalev, S. et al. Quantum Materials 6.1 (2021): 1-6.
[3] Giorgianni, F. et al. Nature Сommunications 7.1 (2016): 1-6.
[4] Bernevig, B. et al. Science 314, 5806 (2006): 1757-1761.
[5] Brüne, C. et al. Phys. Rev. Lett. 106, 12 (2011): 126803.

  • Poster
    International conference on Complexity and Topology in Quantum Matter, 25.-29.07.2022, Würzburg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35953


Data publication: Characterization of laser wakefield acceleration efficiency with octave spanning near-IR spectrum measurements

Streeter, M. J. V.; Ma, Y.; Kettle, B.; Dann, S. J. D.; Gerstmayr, E.; Albert, F.; Bourgeois, N.; Cipiccia, S.; Cole, J. M.; Gallardo González, I.; Hussein, A. E.; Jaroszynski, D. A.; Falk, K.; Krushelnick, K.; Lemos, N.; Lopes, N. C.; Lumsdon, C.; Lundh, O.; Mangles, S. P. D.; Najmudin, Z.; Rajeev, P. P.; Sandberg, R.; Shahzad, M.; Smid, M.; Spesyvtsev, R.; Symes, D. R.; Vieux, G.; Thomas, A. G. R.

Abstract

10.5281/zenodo.7188057

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  • Reseach data in external data repository
    Publication year 2022
    License: Creative Commons Attribution 4.0 International
    Hosted on https://zenodo.org/record/7188057: Link to location
    DOI: 10.5281/zenodo.7188057

Permalink: https://www.hzdr.de/publications/Publ-35952


Characterization of laser wakefield acceleration efficiency with octave spanning near-IR spectrum measurements

Streeter, M. J. V.; Ma, Y.; Kettle, B.; Dann, S. J. D.; Gerstmayr, E.; Albert, F.; Bourgeois, N.; Cipiccia, S.; Cole, J. M.; Gallardo González, I.; Hussein, A. E.; Jaroszynski, D. A.; Falk, K.; Krushelnick, K.; Lemos, N.; Lopes, N. C.; Lumsdon, C.; Lundh, O.; Mangles, S. P. D.; Najmudin, Z.; Rajeev, P. P.; Sandberg, R.; Shahzad, M.; Smid, M.; Spesyvtsev, R.; Symes, D. R.; Vieux, G.; Thomas, A. G. R.

Abstract

We report on experimental measurements of energy transfer efficiencies in a GeV-class laser wakefield accelerator. Both the transfer of energy from the laser to the plasma wakefield and from the plasma to the accelerated electron beam was diagnosed by simultaneous measurement of the deceleration of laser photons and the acceleration of electrons as a function of plasma length. The extraction efficiency, which we define as the ratio of the energy gained by the electron beam to the energy lost by the self-guided laser mode, was maximized at 19±3% by tuning the plasma density and length. The additional information provided by the octave-spanning laser spectrum measurement allows for independent optimization of the plasma efficiency terms, which is required for the key goal of improving the overall efficiency of laser wakefield accelerators.

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Permalink: https://www.hzdr.de/publications/Publ-35951


Deterministic multi-level spin orbit torque switching using focused He+ ion beam irradiation

Kurian, J.; Joseph, A.; Cherifi-Hertel, S.; Fowley, C.; Hlawacek, G.; Dunne, P.; Romeo, M.; Atcheson, G.; Coey, J. M. D.; Doudin, B.

Abstract

He+ ion irradiation is used to pattern multiple areas of Pt/Co/W films with different irradiation doses in Hall bars. The resulting perpendicular magnetic anisotropy landscape enables selective multilevel currentinduced switching, with full deterministic control of the position and order of the individual switching elements. Key pattern design parameters are specified, opening a way to scalable multilevel switching devices.

Keywords: spintronics; spin orbit torque switching; nanomagnetism; ion beam irradiation; Hall bars

Involved research facilities

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Permalink: https://www.hzdr.de/publications/Publ-35950


Material requirements and choices for non destructive pulsed magnets

Zherlitsyn, S.

Abstract

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences)
    2022 MRS fall meeting & exhibit, 27.11.-02.12.2022, Boston, USA

Permalink: https://www.hzdr.de/publications/Publ-35949


Data publication: Intrinsic energy flow in laser-excited 3d ferromagnets

Zahn, D.; Jakobs, F.; Seiler, H.; Butcher, T. A.; Engel, D.; Vorberger, J.; Atxitia, U.; William Windsor, Y.; Ernstorfer, R.

Abstract

DFT data concerning the electronic structure and electron-phonon coupling of Co and Fe. NOT the atomistic spin simulations. NO experimental data.

Keywords: ferromagnet; iron; cobalt; lattice; spin; relaxation

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Permalink: https://www.hzdr.de/publications/Publ-35948


Data publication: Electron-ion temperature relaxation in warm dense hydrogen observed with picosecond resolved X-ray scattering

Fletcher, L. B.; Vorberger, J.; Schumaker, W.; Ruyer, C.; Goede, S.; Galtier, E.; Zastrau, U.; Alves, E. P.; Baalrud, S. D.; Baggott, R. A.; Barbrel, B.; Chen, Z.; Döppner, T.; Gauthier, M.; Granados, E.; Kim, J. B.; Kraus, D.; Lee, H. J.; Macdonald, M. J.; Mishra, R.; Pelka, A.; Ravasio, A.; Roedel, C.; Fry, A. R.; Redmer, R.; Fiuza, F.; Gericke, D. O.; Glenzer, S. H.

Abstract

DFT-MD and HNC data for cryogenic hydrogen and for two-temperature hydrogen

Keywords: warm dense matter; x-ray scattering; relaxation; femtosecond; hydrogen jet

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Permalink: https://www.hzdr.de/publications/Publ-35947


Analyzing the filamentation of MeV-range proton bunches in a laser-driven ion beamline and optimizing their peak intensity

Metternich, M.; Nazary, H.; Schumacher, D.; Brabetz, C.; Kroll, F.; Brack, F.-E.; Ehret, M.; Blažević, A.; Schramm, U.; Bagnoud, V.; Roth, M.

Abstract

In this article, we report on the latest investigations and achievements in proton beam shaping with our laser-driven ion beamline at GSI Helmholtzzentrum für Schwerionenforschung GmbH. This beamline was realized within the framework of the Laser Ion Generation, Handling, and Transport (LIGHT) collaboration to study the combination of laser-driven ion beams with conventional accelerator components. At its current state, the ions are accelerated by the high-power laser PHELIX via target normal sheath acceleration, and two pulsed high-magnetic solenoids are used for energy selection, transport, and transverse focusing. In between the two solenoids, there is a rf cavity that gives the LIGHT beamline the capability to longitudinally manipulate and temporally compress ion bunches to sub-nanosecond durations. To get optimal results, the rf cavity has to be synchronized with the PHELIX laser and therefore a reliable measurement of the temporal ion beam profile is necessary. In the past, these measurements showed unexpected correlations between the temporal beam profile and the phase as well as the electric field strength of the cavity. In this article, we present a numerical simulation of the beam transport through the LIGHT beamline which explains this behavior by a beam filamentation. We also report on our latest experimental campaigns, in which we combined transverse and longitudinal focusing for the first time. This led to proton bunches with a peak intensity of (3.28±0.24)×108 protons/(ns mm2) at a central energy of (7.72±0.14) MeV. The intensity refers to a circle with a diameter of (1.38±0.02) mm that encloses 50% of the protons in the focal spot at the end of the beamline. The temporal bunch width at this position was (742±40) ps (FWHM).

Keywords: Laser acceleration; TNSA; Proton beam; beamline

Permalink: https://www.hzdr.de/publications/Publ-35946


Investigation of the ¹⁰B(p,α)⁷Be reaction from 0.8 to 2.0 MeV

Vande Kolk, B.; Macon, K. T.; Deboer, R. J.; Anderson, T.; Boeltzig, A.; Brandenburg, K.; Brune, C. R.; Chen, Y.; Clark, A. M.; Danley, T.; Frentz, B.; Giri, R.; Görres, J.; Hall, M.; Henderson, S. L.; Holmbeck, E.; Howard, K. B.; Jacobs, D.; Lai, J.; Liu, Q.; Long, J.; Manukyan, K.; Massey, T.; Moran, M.; Morales, L.; Odell, D.; O'Malley, P.; Paneru, S. N.; Richard, A.; Schneider, D.; Skulski, M.; Sensharma, N.; Seymour, C.; Seymour, G.; Soltesz, D.; Strauss, S.; Voinov, A.; Wüstrich, L.; Wiescher, M.

Abstract

Background: A multitude of broad interfering resonances characterize the ¹⁰B(p,α)⁷Be cross section at low energies. The complexity of the reaction mechanism, as well as conflicting experimental measurements, have so far prevented a reliable prediction of the cross section over the energy ranges pertinent for a boron-proton fusion reactor environment.

Purpose: To improve the evaluated cross section of the ¹⁰B(p,α)⁷Be reaction, this study targets the proton energy region from 0.8 to 2.0 MeV, where kinematic overlap of the scattered protons and reaction α particles have made past measurements very challenging.

Method: New detailed studies of the reaction have been performed at the Edwards Accelerator Laboratory at Ohio University and the Nuclear Science Laboratory at the University of Notre Dame using time-of-flight and degrader foil techniques, respectively.

Results: Proton and α-particle signals were clearly resolved using both techniques, and 16 point differential cross sections were measured over an angular range of θlab=45° and 157.5°. A comprehensive R-matrix analysis of the experimental data, including data from previous low-energy studies of the ¹⁰B(p,α)⁷Be, ¹⁰B(p,p)¹⁰B, and ¹⁰B(p,γ)¹¹C reactions, was achieved over the region of measurement. Using a representative set of previous data, the fit was extended to very low energies.

Conclusions: On the basis of this data and R-matrix analysis, a more reliable and consistent description of the ¹⁰B(p,α)⁷Be cross section has been established. The uncertainty over the energy range of this study has been reduced from ≈20% to ≈10%, and the level structure over this region has been clarified considerably.

Permalink: https://www.hzdr.de/publications/Publ-35943


Mineralogy and microfabric as foundation for a new particle-based modelling approach for industrial mineral separation

Pereira, L.

Abstract

\chapter*{Abstract}
The raw materials sector is one of the most important building blocks in the transition to a renewables-based energy system. This is because, as opposed to the current energy system, which relies mainly on fossil fuels, the new system will require a considerable amount of mineral raw materials to construct the devices required for energy production (e.g., solar panels, wild mills, etc.). Despite efforts to boost secondary metal production via recycling in a circular economy framework, substantial volumes of minerals and metals will still need to be added from the geo- to the anthroposphere within the context of the energy transition. This primary investment is inevitable before recycling-based raw material production can satisfy demand. Therefore, mining will remain indispensable for the foreseeable future.

For millennia, our society has been exploring and exploiting mineral deposits. Consequently, most of the easily exploitable high-grade deposits, which were of primary interest given their obvious technical and economic advantages, have already been depleted. For the future, the mining sector will have to efficiently produce metals and minerals from low-grade orebodies with complex mineralogical and microstructural properties -- these are generally referred to as complex orebodies. The exploitation of such complex orebodies carries significant technical risks. However, these risks may be reduced by applying modelling tools that are reliable and robust.

In a broad sense, modelling techniques are already applied to estimate the resources and reserves contained in a deposit, and to evaluate the potential recovery (i.e., behaviour in comminution and separation processes) of these materials. This thesis focusses on the modelling of recovery processes, more specifically mineral separation processes, suited to complex ores.

Despite recent developments in the fields of process mineralogy and geometallurgy, current mineral separation modelling methods do not fully incorporate the available information on ore complexity. While it is well known that the mineralogical and microstructural properties of individual particles control their process behaviour, currently widely applied modelling methods consider only distributions of bulk particle properties, which oftentimes require much simplification of the particle data available. Moreover, many of the methods used in industrial plant design and process modelling are based on the chemical composition of the samples, which is only a proxy for the mineralogical composition of the ores.

A modelling method for mineral separation processes suited to complex ores should be particle-based, taking into consideration all quantifiable particle properties, and capable of estimating uncertainties. Moreover, to achieve a method generalizable to diverse mineral separation units (e.g., magnetic separation or flotation) with minimal human bias, strategies to independently weight the importance of different particle properties for the process(es) under investigation should be incorporated.

This dissertation introduces a novel particle-based separation modelling method which fulfills these requirements. The core of the method consists of a least absolute shrinkage and selection operator-regularized (multinomial) logistic regression model trained with a balanced particle dataset. The required particle data are collected with scanning electron microscopy-based automated mineralogy systems. Ultimately, the method can quantify the recovery probability of individual particles, with minimal human input, considering the joint influence of particle shape, size, and modal and surface compositions, for any separation process.

Three different case studies were modelled successfully using this new method, without the need for case-specific modifications: 1) the industrial recovery of pyrochlore from a carbonatite deposit with three froth flotation and one magnetic separation units, 2) the laboratory-scale magnetic separation of a complex skarn ore, and 3) the laboratory-scale separation of apatite from a sedimentary ore rich in carbonate minerals by flotation. Moreover, the generalization potential of the method was tested by predicting the process outcome of samples which had not been used in the model training phase, but came from the same geometallurgical domain of a specific ore deposit. In each of these cases, the method obtained high predictive accuracy.

In addition to its predictive power, the new particle-based separation modelling method provides detailed insights into the influence of specific particle properties on processing behaviour. To name a couple, the influence of size on the recovery of different carbonate minerals by flotation in an industrial operation; and a comparison to traditional methodologies demonstrated the limitation of only considering particle liberation in process mineralogy studies -- the associated minerals should be evaluated, too. Finally, the potential application of the method to minimize the volume of test work required in metallurgical tests was showcased with a complex ore.

The approach developed here provides a foundation for future developments, which can be used to optimize mineral separation processes based on particle properties. The opportunity exists to develop a similar approach to model the comminution of single particles and ultimately allow for the full prediction of the recovery potential of complex ores.

Keywords: Geometallurgy; particle-based separation model; minerals processing

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Permalink: https://www.hzdr.de/publications/Publ-35942


On the impact of grinding conditions in the flotation of semi-soluble salt-type mineral-containing ores – driven by surface or particle geometry effects?

Pereira, L.; Kupka, N.; Hoang, D. H.; Michaux, B.; Saquran, S. S. S.; Ebert, D.; Rudolph, M.

Abstract

Grinding and flotation operations are often studied independently, despite the well-established grinding influence on flotation performance. At most, this influence is studied with microflotation of pure minerals, which hinders a thorough evaluation of the problem. Here, we study the relation between grinding condition and flotation without material simplification. Clearlier, we assess if variations in flotation performance after distinct grinding environments are driven by particle size and shape or by variations in pulp properties. Three ores were studied: scheelite, apatite, and fluorite. These were dry-, wet-, and wet conditioned-ground before flotation in a laboratory mechanical cell. Results were evaluated with bulk- and particle-specific methodologies. For each grinding environment, variations in flotation performance (e.g., apatite and scheelite particles float faster after dry and wet conditioned-grinding, respectively) and selectivity (e.g., higher after dry grinding for the fluorite and apatite ores and irrelevant for the scheelite ore) were quantified. Yet, the impact of particle shape is system specific, i.e. entrainment increases for rounder particles in the apatite and scheelite ores while true flotation is higher for these particles in the fluorite ore. We conclude that the selectivity of these semi-soluble salt-type mineral systems is driven by pulp chemistry variations caused by distinct grinding environments.

Keywords: grinding-flotation interactions; semi-soluble salt-type minerals; geometallurgy; particle-based modelling; surface interactions

Permalink: https://www.hzdr.de/publications/Publ-35941


ELBE: An Accelerator Driven Radiation Source at its Best

Klopf, J. M.; Arnold, A.; Evtushenko, P.; Freitag, M.; Justus, M.; Kösterke, I.; Kuntzsch, M.; Lehnert, U.; Ryzhov, A.; Schamlott, A.; Schneider, C.; Schurig, R.; Schwarz, A.; Steinbrück, R.; Xiang, R.; Zenker, K.; Michel, P.

Abstract

The heart of the ELBE Center for High Power Radiation Sources is a superconducting RF (SRF) linac, which accelerates electrons up to 35 MeV for driving a diverse set of secondary radiation sources. The ELBE linac is particularly unique in the capability of accelerating a continuous beam of ultrashort bunches of electrons at very high repetition rates (up to 26 MHz). This extremely high-power electron beam is selectively directed into specially designed beamlines to drive secondary radiation sources for THz/IR photons (FELBE and TELBE), positrons (pELBE), neutrons (nELBE), and gamma radiation (ELBE), each with dedicated laboratories and instrumentation. Users from all over the world utilize the advanced radiation sources at ELBE for a wide array of both fundamental and applied studies of matter, health, energy, and technology.
The ELBE accelerator was first commissioned in 2001 in the form of a grid-pulsed 250 kV thermionic gun followed by two stages of RF bunching to inject beam into a linac comprised of two SRF cryomodules, each containing two 9-cell DESY TTF-type niobium accelerating cavities. Through continuous development and research, the ELBE facility has achieved many major advancements in accelerator technology, the most important being the ELBE SRF Gun program, which has designed, built, and commissioned several prototype SRF electron guns for high bunch charge, high average current, and low emittance. The ELBE SRF Gun-II is the first and only electron source of its type to deliver electron beam to a user experiment, and is now in routine operation for the TELBE and pELBE beamlines.
An overview of the performance parameters of the ELBE accelerator and secondary sources will be presented in this talk along with a summary of the experimental capabilities available to users. Highlights of recent user results will also be presented to help illustrate the great potential ELBE provides for a diverse scientific community. Beamtime proposals are accepted and reviewed by an external scientific advisory committee twice per year.
https://www.hzdr.de/db/Cms?pNid=1732

Keywords: linac; SRF; electron accelerator; FEL; THz; positrons; neutrons; gamma radiation

Involved research facilities

Related publications

  • Invited lecture (Conferences)
    UWr – CASUS – HZDR International Conference on Advanced Systems Research, 11.-15.07.2022, Hotel Wyndham Wrocław Old Town, Poland

Permalink: https://www.hzdr.de/publications/Publ-35940


Underground Measurements of Nuclear Reaction Cross-Sections Relevant to AGB Stars

Ananna, C.; Barile, F.; Boeltzig, A.; Giulio Bruno, C.; Cavanna, F.; Francesco Ciani, G.; Compagnucci, A.; Csedreki, L.; Depalo, R.; Ferraro, F.; Masha, E.; Piatti, D.; Rapagnani, D.; Skowronski, J.

Abstract

Nuclear reaction cross sections are essential ingredients to predict the evolution of AGB stars and understand their impact on the chemical evolution of our Galaxy. Unfortunately, the cross sections of the reactions involved are often very small and challenging to measure in laboratories on Earth. In this context, major steps forward were made with the advent of underground nuclear astrophysics, pioneered by the Laboratory for Underground Nuclear Astrophysics (LUNA). The present paper reviews the contribution of LUNA to our understanding of the evolution of AGB stars and related nucleosynthesis.

Keywords: Underground Nuclear Astrophysics; Stellar Evolution; Stellar Nucleosynthesis

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Permalink: https://www.hzdr.de/publications/Publ-35939


Applying particle-based separation modelling on 3D particle data to better quantify the influence of particle size and shape in flotation

Guimaraes Da Silva Tochtrop, C.; Pereira, L.; Da Assuncao Godinho, J. R.; Gupta, S.; Liipo, J.; Boone, M.; Rudolph, M.

Abstract

X-Ray computed tomography (XRCT) enables the 3D characterization of particulate materials with a better description of their micro-structural and geometric properties. Recent developments permit quantifying accurately the composition of the particulate material in 3D. Particle-based separation modelling methods have driven significant studies relating microstructural properties with particle process behaviour. Yet, these methods have never been fed with the more complete 3D XRCT particle data. We address this gap in this work.
We use as a case study the flotation of a sulphide-rich ore, where we quantify the relation between the flotation kinetics of individual particles, their microstructural properties and two flotation cell hydrodynamic parameters: rotational speed and air flow rate. Given the meticulous description of particle geometric properties provided by XRCT, we obtained a more precise evaluation of the influence of particle shape in its recovery. This methodology is also applicable to other ores and mineral separation units.

Keywords: Geometallurgy; particle-based separation model; 3D particle characterization

  • Contribution to proceedings
    Process Mineralogy, 01.-04.11.2022, Sitges, Spain
    Process Mineralogy '22

Permalink: https://www.hzdr.de/publications/Publ-35938


The Future of 3D Characterization

Pereira, L.; Da Assuncao Godinho, J. R.; Boone, M.; Heron, M.

Abstract

The partners of the EIT Raw Materials funded project 2D3Dscopy kindly invite you to "The Future of 3D Characterization" prior to the 2022 MEI conference in Process Mineralogy in November. The workshop will provide you with insides into the latest developments in 3D particle characterization and particle-based process optimization.

Keywords: Geometallurgy; particle-based separation model; 3D particle characterization

  • Lecture (Conference)
    Process Mineralogy, 01.-04.11.2022, Sitges, Spain

Permalink: https://www.hzdr.de/publications/Publ-35937


The FELBE THz/IR FEL: Overview of the Facility and User Activities

Klopf, J. M.; Evtushenko, P.; Helm, M.; Kehr, S. C.; Lehnert, U.; Michel, P.; Pashkin, O.; Winnerl, S.; Zvyagin, S.

Abstract

The FELBE User Facility at the ELBE Center for High-Power Radiation Sources offers a pair of FELs that deliver beam to eight different user labs. The FELs are driven by a two-stage Superconducting RF (SRF) linac, which produces a quasi-CW beam (13 MHz/1 mA) at an energy of up to 36 MeV. The tuning range spanned by the two FELs extends from the mid IR to THz (5 – 250 m). The spectral range and ultrashort pulse width (p ≈ 0.7 – 25 ps) are ideal for time-resolved measurements of many types of transient processes in low-dimensional materials [1], quantum structures [2], and correlated systems [3]. The high pulse energy can also drive nonlinear phenomena [4] and strong coupling [5] in light-matter interactions. The FELBE User Labs are equipped with instrumentation and synchronized ultrashort table-top lasers (i.e. Ti:Sa oscillators, regens, OPAs, SFG/DFG) which facilitate various classes of degenerate (single-color), and non-degenerate (two-color) pump-probe experiments. Optical cryostats and an 8 T split coil magnet are also available for low temperature and magnetic field dependent studies. Furthermore, the FELBE beamline extends into the adjacent High Field Magnet Lab (HLD) for performing magneto-optical spectroscopy measurements at fields up to 70 T [6]. The high repetition rate and tunability of the FELBE beam has uniquely enabled revolutionary methods in scattering-Scanning Nearfield Optical Microscopy (s­SNOM) to image novel light-matter interactions with resolution far below the diffraction limit [7]. Proposals for beamtime on FELBE and the other secondary sources at ELBE are invited from users twice a year.
(https://www.hzdr.de/FELBE).

[1] T. Venanzi, et al., ACS Photonics 8, 2931-2939 (2021).
[2] J. Schmidt, et al., Optics Express 28, 25358-25370 (2020).
[3] M. M. Jadidi, et al., Phys. Rev. B 102, 245123 (2020).
[4] F. Meng, et al., Phys. Rev. B 102, 075205 (2020).
[5] B. Piętka, et al., Phys. Rev. Lett. 119, 077403 (2017).
[6] M. Ozerov, et al., Phys. Rev. Lett. 113, 157205 (2014).
[7] T. V. A. G. de Oliveira, et al., Adv. Mater. 33, 2005777 (2021).

Keywords: THz; FEL; ultrafast dynamics; correlated systems; low-dimmensional materials; quantum structures; nanoscale

Involved research facilities

Related publications

  • Invited lecture (Conferences)
    TERFEL : International Conference on Free Electrons Laser Applications in Infrared and THz Studies of New States of Matter, 05.-08.07.2022, Novotel Warszawa Centrum, Poland

Permalink: https://www.hzdr.de/publications/Publ-35936


Predictive Geometallurgy - SGA Shortcourse

Tolosana Delgado, R.; Pereira, L.; Frenzel, M.; Da Assuncao Godinho, J. R.; Birtel, S.; de Boever, W.; Dosbaba, M.; Taylor, R.; Gutzmer, J.

Abstract

Geometallurgy aims to optimise the mineral value chain based on a spatially resolved, precise and quantitative understanding of the geology and mineralogy of the ores. Predictive geometallurgy goes beyond this by introducing forecasting models for ore behaviour, and taking into account operational economics and global mineral markets. The course is divided into two main blocks: First, introductory presentations on advanced material characterization as well as current principles and applications of geometallurgy are pre-recorded, and can be watched independently by the audience.
The second part of the course will consist of a live interactive session with time to discuss questions on the talks with the presenters. Its major goal is to enforce the concepts developed in the first part of the course through hands-on exercises using web-based apps. This will allow participants to get a good feel for the data types common in geometallurgical programmes, and how they can be integrated into a geometallurgical model to be used in mine planning, scheduling and mine optimisation.

Keywords: Geometallurgy; 3D particle characterization; geostatistics; particle-based separation modelling

  • Lecture (Conference) (Online presentation)
    SGA Biennial meeting, 26.-31.03.2022, Rotorua, New Zealand

Permalink: https://www.hzdr.de/publications/Publ-35935


LUNA (Laboratory for Underground Nuclear Astrophysics): A Long Success Story with New Goals in Sight

Imbriani, G.; Junker, M.; Boeltzig, A.; Ciani, G. F.; Piatti, D.

Keywords: LUNA; Nuclear Astrophysics; Underground; Ion Beam Accelerator; Nuclear Cross Section Measurements; Low-Background; Gran Sasso National Laboratory (LNGS)

Related publications

Permalink: https://www.hzdr.de/publications/Publ-35934


Particle-based modelling applied to understand the influence of comminution environment on the flotation of semi-soluble salt type minerals

Pereira, L.; Kupka, N.; Hoang, D. H.; Michaux, B.; Saquran, S. S. S.; Ebert, D.; Rudolph, M.

Abstract

Semi-soluble salt type minerals (SSSM) are important industrial minerals as well as common gangue minerals in diverse metal deposits. Being able to understand and improve the process behaviour of these minerals is thus of high relevance for many parts of the raw materials value chain. The surface properties as well as the interactions of these minerals with the fluid media grant them a distinguishable behaviour in flotation. In this study, we investigate the influence of particle geometric properties (size and shape) caused by distinct comminution environments (dry, wet, and wet with reagents) on the process behaviour of three ore types containing SSSM: an apatite, a fluorite, and a scheelite ore. A particle-based separation modelling method was applied to quantify the flotation kinetics of individual particles according to all tangible properties quantifiable with automated mineralogy (modal and surface composition, size, and shape). Our approach, which requires minimal human-input, captured well-documented flotation behaviours related to particle size (e.g., the Rmax of minerals recovered via entrainment is generally higher for the fine size fraction). In regards to particle shape, it clearly influences the flotation behaviour of particles. Yet, even in a controlled study such as we have performed here, the relation between mineral type, grinding environment, and flotation performance is very convoluted and no general conclusion can be drawn. This challenge in evaluating the influence of particle shape in flotation can explain the high number of controversial studies regarding the topic.

Keywords: Geometallurgy; Comminution; Semi-soluble salt-type minerals; flotation; particle-based separation modelling

  • Contribution to proceedings
    Procemin Geomet 2022, 05.-07.10.2022, Santiago, Chile
    18th International Conference on Mineral Processing and Geometallurgy

Permalink: https://www.hzdr.de/publications/Publ-35933


Using particle-based separation models to evaluate the selectivity of different collectors in chalcopyrite flotation

Pereira, L.; Schach, E.; Frenzel, M.; Tolosana Delgado, R.; Rudolph, M.; Gutzmer, J.

Abstract

Particle-based separation models are a powerful tool for modelling and understanding mineral separation processes at the level of single particles. Latest developments in this field have enabled the incorporation of complete particle datasets from image-analysis based techniques, thus allowing for the full integration of material complexity into process models. So far, these models have mostly been applied to static processes, without variations in operating conditions. In this contribution, we used particle-based separation models to understand variations in the flotation behavior of a fine-grained and low-grade chalcopyrite-dominated copper ore using different collectors: PAX and kerosene. This approach highlights the influence of particle size and shape on the flotation of chalcopyrite-bearing particles. Moreover, it demonstrates that detailed information on mineral associations is critical to achieve a full description of the process behavior of single particles. Full association data should therefore be used instead of simplified ore mineral liberation data whenever possible. Finally, results indicate that higher selectivity against pyrite can be achieved when kerosene is used as a collector instead of PAX. In addition, ideas for improving separation (e.g., higher grade and recovery) are discussed based on detailed particle information.

Keywords: Geometallurgy; particle-based separation model; chalcopyrite; pyrite; kerosene; pax; flotation

  • Contribution to proceedings
    Copper International Conference 2022, 13.-17.11.2022, Santiago, Chile
    Volume 10: Geometallurgy

Permalink: https://www.hzdr.de/publications/Publ-35932


Effects of surfactant on lift coefficient of ellipsoidal bubbles in the viscous-force dominant regime

Chen, J.; Hayashi, K.; Legendre, D.; Lucas, D.; Tomiyama, A.

Abstract

Effects of surfactants on lift coefficients, CL, of single ellipsoidal bubbles rising through linear shear flows were investigated. Two types of surface-active agents, i.e. Triton X-100 and 1-octanol, were used. The liquid properties except for the surface tension were identical to those in a clean system of logM = -5.5, where M is the Morton number. The range of the bubble Reynolds number was 0.1 < Re < 70. Bubble shapes were either spherical or ellipsoidal. Comparing with clean bubbles, less deformation of contaminated bubbles was confirmed due to the fact that surfactant tends to accumulate on the bubble interface, making it behave like solid particles. A shape correlation without taking the dimensionless shear rate into account gave good evaluations of the bubble aspect ratio, which means that the shear rate is not a dominant factor causing the change of shape deformation. However, drag coefficients were affected by the shear rate. Making use of a correlation for bubbles in stagnant liquid, a new correlation of drag coefficients was deduced, which agreed well with the experimental data. Both clean and contaminated CL data showed similar tendency, i.e. after a drastic decrease to a local minimum, CL value slightly increases with increasing the bubble Reynolds number, Re, and then gradually decreases to negative values. A difference in concentration of Trion X-100 resulted in only a slight change in CL at high Re regime. Different types of surfactant resulted in noticeably different values of CL especially at low Re. The CL of small spherical bubbles in contaminated systems could be reproduced by a correlation for solid particles, supporting that fully-contaminated spherical bubbles behave like solid spheres. For deformed bubbles, the lift coefficients can be expressed by relating the negative lift force due to shape deformation with the drag force.

Keywords: Bubble; Aspect ratio; Surfactant; Lift coeffcient

Permalink: https://www.hzdr.de/publications/Publ-35931


Bioleaching of mine tailings using acidophilic bacteria and organic acids

Kaufer, T.; Kutschke, S.; Pollmann, K.

Abstract

Fine-grained tailings from ore processing represent a considerable raw material potential and could be used in the cement industry, as base and surface sealing material for landfills or for dam construction. Those mine tailings are mostly deposited wet in so-called tailings ponds. Storage involves a certain environmental risk, for example mobilization of heavy metals and dam failures with catastrophic consequences. To prevent such environmental disasters in the future and to make these raw materials reusable again, a remediation concept for tailings ponds is therefore necessary. Bioleaching is to be used to modify the composition of the material to meet certain guidelines for its use in the construction industry. For this purpose, various acidophilic bacteria such as Sulfobacillus acidophilus DSM 10332, Leptospirillum ferrooxidans DSM 2705 and other acidophilic consortia were tested. In addition, the yeast Yarrowia lipolytica DSM 3286 was cultivated for the production of citric acid and the bacterium Bacillus licheniformis DSM 13 was cultivated for the production of γ-polyglutamic acid. The bioleaching with these organic acid supernatants and 10 % tailing concentration showed the most promising results to date. The culture supernatant containing 30 g/L citric acid was able to leach 43 % of Pb, 37 % of Zn, 8 % of Ca, 4 % of Mn and 3 % of Fe. Further research and a combination of different processes such as flotation and chemical leaching will also be necessary to optimize the extraction capacities. The authors acknowledge the financial support by the Federal Ministry of Education and Research of Germany in the framework of “Resource Efficient Circular Economy – Construction and Mineral Material Cycles (ReMin)”

Keywords: Bioleaching; Remediation; acidophilic bacteria; Yeast; Mineral Tailings

  • Poster
    Emerging Applications of Microbes (2nd edition), 07.-08.12.2022, Leuven, Belgien

Permalink: https://www.hzdr.de/publications/Publ-35930


Demonstration of Trojan horse injection in a hybrid LWFA-driven PWFA

Ufer, P.; Nutter, A.; Chang, Y.-Y.; Corde, S.; Couperus Cabadağ, J. P.; Debus, A.; Döpp, A.; Moritz Foerster, F.; Gilljohann, M.; Heinemann, T.; Hidding, B.; Karsch, S.; Köhler, A.; Kononenko, O.; Pausch, R.; Schöbel, S.; Martinez De La Ossa, A.; Schramm, U.; Irman, A.

Abstract

In a hybrid LWFA-driven PWFA (LPWFA) electron beams from a laser wakefield acceleration (LWFA) stage are utilized to drive a plasma wave in a subsequent plasma wakefield acceleration (PWFA) stage for acceleration of witness electron bunches to high energies. This concept allows for the exploration of PWFA-physics in a compact setup and harnessing the advantages of both plasma acceleration schemes in order to generate high-quality electron beams. Here we present results of Trojan horse injection in this hybrid plasma acceleration configuration. The DRACO laser is focused onto a gas target (LWFA stage), creating a plasma wakefield to accelerate a high peak current electron bunch. While such a beam is propagating in the second gas jet (PWFA stage), consisting of a mixture of high and low ionization threshold gas, an auxiliary low energy laser pulse intercepts the generated wakefield perpendicularly to release electrons from the highest ionization level in the first cavity. The generated witness beams show improved beam quality, such as lower energy spread compared to the drive electron beam. The realization of Trojan horse injection in LPWFA is a further step towards applications based on high brightness electron beams such as free electron lasers.

Involved research facilities

  • Draco
  • Poster
    EuroNNAc Special Topics Workshop, 18.-24.09.2022, La Biodola, Italia

Permalink: https://www.hzdr.de/publications/Publ-35929


High-order nonlinear terahertz probing of the two-band superconductor MgB2: Third- and fifth-order harmonic generation

Reinhoffer, C.; Pilch, P.; Reinold, A.; Derendorf, P.; Kovalev, S.; Deinert, J.-C.; Ilyakov, I.; Ponomaryov, O.; Chen, M.; Xu, T.-Q.; Wang, Y.; Gan, Z.-Z.; Wu, D.-S.; Luo, J.-L.; Germanskiy, S.; Mashkovich, E. A.; van Loosdrecht, P. H. M.; Eremin, I. M.; Wang, Z.

Abstract

We report on high-order harmonic generation in the two-band superconductor MgB 2 driven by intense
terahertz electromagnetic pulses. Third- and fifth-order harmonics are resolved in time domain and investigated
as a function of temperature and in applied magnetic fields crossing the superconducting phase boundary. The
high-order harmonics in the superconducting phase reflects nonequilibrium dynamics of the superconducting
order parameter in MgB2, which is probed via nonlinear coupling to the terahertz field. The observed temperature
and field dependence of the nonlinear response allows to establish the superconducting phase diagram.

Keywords: Terahertz; Superconductivity; Harmonic Generation; Magnetic Fields; Nonlinear Processes

Involved research facilities

Related publications

Downloads

Permalink: https://www.hzdr.de/publications/Publ-35928


Experimental results of Trojan horse injection in a hybrid LPWFA

Ufer, P.; Nutter, A.; Chang, Y.-Y.; Corde, S.; Couperus Cabadağ, J. P.; Debus, A.; Döpp, A.; Heinemann, T.; Hidding, B.; Gilljohann, M.; Karsch, S.; Köhler, A.; Kononenko, O.; Pausch, R.; Schöbel, S.; Martinez De La Ossa, A.; Schramm, U.; Irman, A.

Abstract

A hybrid (LPWFA) plasma accelerator combines the two schemes of plasma acceleration, using a laser (LWFA) and an electron beam (PWFA) to drive the plasma wave, with the goal to combine the advantages of both methods. This concept allows studies of PWFA-physics in compact setups as well as generating high-quality electron beams to fulfill the demands of secondary light sources like FELs. We present experimental results from hybrid plasma accelerators using plasma cathode injection also known as Trojan horse injection. A short-pulsed laser is used as the injector in the second stage of the accelerator propagating perpendicular to the electron beam. When timed such, that injector laser and the first cavity of the wakefield overlap, the creation of low-energy-spread witness beams have been observed.

Involved research facilities

  • Draco
  • Lecture (Conference) (Online presentation)
    DPG-Frühjahrstagung Mainz, 28.03.-01.04.2022, Mainz, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35927


Data publication: Particle yields for Mu2e-II target designs

Müller, S.; Mackenzie, M.; Pronskikh, V. S.

Abstract

Simulated negative muon and pion yields from Mu2e-II target designs.
The work is related to Fermilab LDRD "Pion-production target conceptual studies for Mu2e-II" (FNAL-LDRD-2020-020)

Keywords: Mu2e-II; FLUKA; MARS15; GEANT4; Monte Carlo; Radiation Transport

Related publications

Permalink: https://www.hzdr.de/publications/Publ-35926


Beam driven wakefield characteristics probed by femtosecond-scale shadowgraphy

Schöbel, S.; Pausch, R.; Chang, Y.-Y.; Corde, S.; Couperus Cabadağ, J. P.; Debus, A.; Ding, H.; Döpp, A.; Förster, M.; Gilljohann, M.; Haberstroh, F.; Heinemann, T.; Hidding, B.; Karsch, S.; Köhler, A.; Kononenko, O.; Nutter, A.; Steiniger, K.; Ufer, P.; Martinez De La Ossa, A.; Schramm, U.; Irman, A.

Abstract

High peak current electron beams from laser wakefield accelerators (LWFA) are capable to drive a particle driven wakefield (PWFA) in a subsequent stage. The intrinsic short duration of these driver beams opens the possibility for PWFA studies in a higher density regime of the order of 1018·cm-3. Since optical probing provides a reasonable contrast at this density range, direct insight into the particle-driven wakefields is possible. Here we present the results of femtosecond optical probing of such beam driven wakefields, showing pronounced differences in the morphology of beam driven plasma waves when surrounded by either neutral gas or a broad pre-generated plasma channel. Moreover, the shape and size of the first cavity of the wakefields correlates with the driver beam charge. The experimental results are supported by 3D particle-in-cell simulations performed with PIConGPU. This method can be extended to a detailed study of driver charge depletion by probing the evolution of the wakefield as it propagates through the plasma. This is an important step for further understanding and optimization of high energy efficiency PWFAs.

Involved research facilities

  • Draco
  • Invited lecture (Conferences)
    EuroNNAc Special Topics Workshop, 18.-24.09.2022, La Biodola, Italia
  • Poster
    EuroNNAc Special Topics Workshop, 18.09.-24.12.2022, La Biodola, Italia
  • Poster
    767. WE-Heraeus-Seminar: Science and Applications of Plasma‐Based Accelerators, 15.-18.05.2022, Bad Honeff, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35925


Excitation of beam driven plasma waves in a hybrid LPWFA

Schöbel, S.; Pausch, R.; Carstens, F.-O.; Chang, Y.-Y.; Corde, S.; Couperus Cabadağ, J. P.; Debus, A.; Ding, H.; Döpp, A.; Heinemann, T.; Hidding, B.; Gilljohann, M.; Karsch, S.; Köhler, A.; Kononenko, O.; Nutter, A.; Ufer, P.; Martinez De La Ossa, A.; Schramm, U.; Irman, A.

Abstract

High peak current electron beams from laser wakefield accelerators (LWFA) are capable to drive a particle driven wakefield (PWFA) in a subsequent stage. The intrinsic short duration of these driver beams opens the possibility for PWFA studies in a higher density regime of the order of 1018·cm-3. Since optical probing provides a reasonable contrast at this density range, direct insight into the particle-driven wakefields is possible. Here we present the results of femtosecond optical probing of such beam driven wakefields, showing pronounced differences in the morphology of beam driven plasma waves when surrounded by either neutral gas or a broad pre-generated plasma channel. Moreover, the shape and size of the first cavity of the wakefields correlates with the driver beam charge. The experimental results are supported by 3D particle-in-cell simulations performed with PIConGPU. This method can be extended to a detailed study of driver charge depletion by probing the evolution of the wakefield as it propagates through the plasma. This is an important step for further understanding and optimization of high energy efficiency PWFAs.

Involved research facilities

  • Draco
  • Lecture (Conference) (Online presentation)
    DPG-Frühjahrstagung, 28.03.-01.04.2022, Mainz, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35924


Increased relative biological effectiveness and periventricular radiosensitivity in proton therapy of glioma patients

Eulitz, J.; Troost, E. G. C.; Klünder, L.; Raschke, F.; Hahn, C.; Schulz, E.; Seidlitz, A.; Thiem, J.; Karpowitz, C.; Hahlbohm, P.; Grey, A.; Engellandt, K.; Löck, S.; Krause, M.; Lühr, A.

Abstract

Purpose

Currently, there is an intense debate on variations in intra-cerebral radiosensitivity and relative biological effectiveness (RBE) in proton therapy of primary brain tumours. Here, both effects were retrospectively investigated using late radiation-induced brain injuries (RIBI) observed in follow-up after proton therapy of patients with diagnosed glioma.
Methods

In total, 42 WHO grade 2–3 glioma patients out of a consecutive patient cohort having received (adjuvant) proton radio(chemo)therapy between 2014 and 2017 were eligible for analysis. RIBI lesions (symptomatic or clinically asymptomatic) were diagnosed and delineated on contrast-enhanced T1-weighted magnetic resonance imaging scans obtained in the first two years of follow-up. Correlation of RIBI location and occurrence with dose (D), proton dose-averaged linear energy transfer (LET) and variable RBE dose parameters were tested in voxel- and in patient-wise logistic regression analyses. Additionally, anatomical and clinical parameters were considered. Model performance was estimated through cross-validated area-under-the-curve (AUC) values.
Results

In total, 64 RIBI lesions were diagnosed in 21 patients. The median time between start of proton radio(chemo)therapy and RIBI appearance was 10.2 months. Median distances of the RIBI volume centres to the cerebral ventricles and to the clinical target volume border were 2.1 mm and 1.3 mm, respectively. In voxel-wise regression, the multivariable model with D, D × LET and periventricular region (PVR) revealed the highest AUC of 0.90 (95 % confidence interval: 0.89–0.91) while the corresponding model without D × LET revealed a value of 0.84 (0.83–0.86). In patient-level analysis, the equivalent uniform dose (EUD11, a = 11) in the PVR using a variable RBE was the most prominent predictor for RIBI with an AUC of 0.63 (0.32–0.90).
Conclusions

In this glioma cohort, an increased radiosensitivity within the PVR was observed as well as a spatial correlation of RIBI with an increased RBE. Both need to be considered when delivering radio(chemo)therapy using proton beams.

Keywords: Proton therapy; Glioma brain tumours; Radiation-induced brain injury; Periventricular region; RBE; LET

Permalink: https://www.hzdr.de/publications/Publ-35923


Spin–orbital liquid state and liquid–gas metamagnetic transition on a pyrochlore lattice

Tang, N.; Kotte, R.; Kimura, K.; Bhattacharjee, S.; Sakai, A.; Fu, M.; Takeda, H.; Man, H.; Sugawara, K.; Matsumoto, Y.; Shimura, Y.; Wen, J.; Broholm, C.; Sawa, H.; Takigawa, M.; Sakakibara, T.; Zherlitsyn, S.; Wosnitza, J.; Moessner, R.; Nakatsuji, S.

Abstract

Crystal structures with degenerate electronic orbitals are unstable towards lattice distortions that lift the degeneracy. Although these Jahn–Teller distortions have profound effects on magnetism, they are typically unaffected by the onset of magnetic ordering because of a separation in energy scales. Here we show the contrary case in Pr2Zr2O7, where orbital degeneracy remains down to the millikelvin range due to an interplay between spins and orbitals. Pr2Zr2O7 is a multipolar spin ice with strongly localized 4f electrons in an even-number configuration, giving rise to a non-Kramers doublet that carries transverse quadrupolar and longitudinal dipolar moments. Our study of ultrapure single crystals of Pr2Zr2O7 finds comprehensive evidence for enhanced spin–orbital quantum dynamics of the non-Kramers doublet. This dynamical Jahn–Teller effect is encapsulated by the liquid–gas metamagnetic transition that is characteristic of spin ice being accompanied by strong lattice softening. This behaviour suggests that a spin–orbital liquid state forms on the pyrochlore lattice at low
temperatures and low magnetic fields.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)

Permalink: https://www.hzdr.de/publications/Publ-35922


Diffusion in Liquid Mixtures

Vailati, A.; Bataller, H.; Bou-Ali, M.; Carpineti, M.; Cerbino, R.; Croccolo, F.; Egelhaaf, S.; Giavazzi, F.; Giraudet, C.; Guevara-Carrion, G.; Horváth, D.; Köhler, W.; Mialdun, A.; Porter, J.; Schwarzenberger, K.; Shevtsova, V.; de Wit, A.

Abstract

The understanding of transport and mixing in fluids in the presence and in the absence of external fields represents a challenging topic of strategic relevance for space exploration. Indeed, mixing and transport of components in a fluid are especially important during long term space missions where fuels, food, and other materials, needed for the sustainability of long space travels, must be processed under microgravity conditions. So far, the processes of transport and mixing have been investigated mainly at the macroscopic and microscopic scale. Their investigation at the mesoscopic scale is becoming increasingly important for the understanding of mass transfer in confined systems, such as porous media, biological systems, and microfluidic systems. Microgravity conditions will provide the opportunity to analyse the effect of external fields on optimizing mixing and transport in the absence of the convective flows induced by buoyancy on Earth. This would be of great practical applicative relevance to handle complex fluids under microgravity conditions for the processing of materials in space.

Permalink: https://www.hzdr.de/publications/Publ-35921


Real-time and online adaptive particle therapy in 10 years: a Delphi consensus analysis

Trenkova, P.; Zhang, Y.; Toshito, T.; Heijmen, B.; Richter, C.; Aznar, M.; Albertini, F.; Bolsi, A.; Daartz, J.; Knopf, A.; Bertholet, J.

Abstract

Real-time and online adaptive particle therapy in 10 years: a Delphi consensus analysis

P. Trnkova1, Y. Zhang2, T. Toshito3, B. Heijmen4, C. Richter5, M. Aznar6, F. Albertini2, A. Bolsi2, J. Daartz7, A. Knopf2,8, J. Bertholet9

1Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
2Center for Proton Therapy, Paul Scherrer Institute; Villigen, Switzerland
3Nagoya Proton Therapy Center, Nagoya City University West Medical Center, Nagoya, Japan
4Department of Radiotherapy, Erasmus University Medical Center (Erasmus MC), Rotterdam, the Netherlands
5 OncoRay – National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden – Rossendorf, Dresden, Germany
6 Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
7Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston MA 02114, United States of America
8 Institute for Medical Engineering and Medical Informatics, School of Life Sciences, University for Applied Sciences and Arts Northwestern Switzerland.
9 Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, Bern, Switzerland

Purpose/objectives: To collect experts’ opinion on the future of Online Adaptive Particle Therapy (OAPT) and Real Time Motion Management (RRMM) for a vision with a ten-year horizon.
Material/Methods: Following the POP-ART PT survey on current status [1], the present 3-round Delphi consensus study addresses the future of OAPT and RRMM with a panel of 11 experts using questionnaires. Second and third rounds were adapted based on the answers from the previous round to generate controlled opinion feedback (Figure 1). Full consensus (FC) or partial consensus (PC) were reached when all experts agreed or only one expert had a different opinion, respectively.
Results: OAPT will be the method of choice in ten years (PC), mainly in case of variable organ filling and performed with a single in-room imaging modality (FC). There was no consensus on whether offline adaptation will still be performed once OAPT is used clinically. All steps of OAPT require automation to maintain patient throughput (FC). Artificial Intelligence is needed for safe automation, with its central role seen in auto-segmentation (FC). Standardising reporting of endpoints in clinical trials (PC) and cumulative dose reporting (PC) is necessary. It is not currently clear what the best and fastest patient QA method for OAPT will be, and further investigations are required to answer this question (FC). As efficient workflows and tools are medical products, the clinical implementation requires cooperation between industry, research and clinic (FC) with automated and fast systems, reliable deformable registration for dose accumulation, and higher quality in-room imaging identified as the top three priorities (PC). The future importance of MRI-guided PT did not reach consensus.
RRMM is needed for near-real-time OAPT and to treat moving targets (FC) as it mitigates dose deteriorations for both, target and OARs (FC). It should combine multiple approaches, including breath-hold, rescanning, gating, or tracking (FC) based on individual patient selection criteria (FC) and pre-treatment motion characteristics (FC). Optimisation of rescanning parameters, motion model uncertainties and pre-treatment 4D evaluation were considered clinically important (FC). The need to report fractional 4D dose distribution in clinical trials did not reach consensus. 4D dose calculation and its uncertainty evaluation were identified as top requirements (FC). 4D log-file dose reconstruction, (surface) image-based gating/tracking, efficient image guidance and on-board MR guidance were considered of interest but without reaching consensus.
Conclusion: A DELPHI consensus analysis was performed to explore needed developments for OAPT and RRMM. Join efforts between industry research and clinics are needed to translate innovations into efficient and clinically feasible workflows for broad-scale implementation. Consistent reporting of well-defined endpoints should be included in clinical trials to evaluate the clinical impact of both methods.
[1] Zhang Y, Trnkova P et al, ESTRO 2021
Key words: Real time motion management, online adaptive particle therapy, consensus opinion

Involved research facilities

  • OncoRay
  • Lecture (Conference)
    ESTRO 2023, 12.-16.05.2023, Vienna, Austria
  • Abstract in refereed journal
    Radiotherapy and Oncology 182(2023)S1, S1623-S1624
    DOI: 10.1016/S0167-8140(23)66795-7

Permalink: https://www.hzdr.de/publications/Publ-35920


Laser-magnetization of Fe60Al40 investigated by pump-probe reflectometry

Pflug, T.; Pablo-Navarro, J.; Olbrich, M.; Horn, A.; Bali, R.

Abstract

Ultrashort pulsed laser irradiation enables the generation of ferromagnetism in initially non-ferromagnetic materials, such as B2-ordered Fe60Al40. The paramagnetic B2 phase, defined by atomic planes of pure Fe, separated by Al-rich planes is randomized due to irradiation leading to the formation of the disordered A2 Fe60Al40 being ferromagnetic. This phase transition has been reported to rely on melting and subsequent resolidification, estimated to occur within 5 ns. However, the physical dynamics during the B2-A2 transition have yet to be investigated. Here, we demonstrate the temporal evolution of the
transient reflectance of Fe60Al40 during the B2-A2 transition measured by pump-probe reflectometry. The reflectance increases abruptly 5 ps after excitation with pulsed laser radiation (800 nm, 40 fs, 0.2 J/cm2) which can be attributed to the disordering process. Ex situ observations (Kerr microscopy, HR-TEM, electron holography) confirm that the laser-irradiated areas possess a high magnetization and the A2 structure. Furthermore, materials whose phase transition does not necessarily rely on resolidification may lead to a further reduction in the time needed for generating ferromagnetism by laser irradiation.

  • Lecture (Conference)
    DPG-Frühjahrstagung der Sektion Materie und Kosmos (SMuK), 20.-24.03.2023, Dresden, Germany

Permalink: https://www.hzdr.de/publications/Publ-35919


Super-SIMS - from the idea to first measurements

Ziegenrücker, R.; Rugel, G.; Koll, D.; Lachner, J.; Renno, A.; Vivo Vilches, C.; Wallner, A.; Wiedenbeck, M.

Abstract

The Dresden Super-SIMS is a combination of the DREAMS facility and a CAMECA IMS7f-auto as the ion source, and combines the advantages of both worlds: on one hand the suppression of molecular isobaric background with a 6MV tandem accelerator and on the other the special and depth resolved information about the origin of the measured signals in the sample. This is possible without the samples undergoing any chemical treatment, and a polished surface (< a few nm) is sufficient for the measurement. While former attempts were intended to analyse semiconductor samples, the primary aim of Super-SIMS is the measurement of geological samples.
Nevertheless, first experiments were done with silicon to characterise the system and compare it with former attempts. Several samples
with known content of phosphorus, including the blank, from the former URI-Project (Ultra clean injector) at the Technical University of
Munich were measured. The sample with highest P content was used as internal reference material and the measurements showed a good agreement between measured concentrations by Super-SIMS and URI.

Keywords: SIMS; Super-SIMS; TEAMS; AMS; Phosphorous; molecular interference; accalerator

Involved research facilities

Related publications

  • Poster
    DPG-Frühjahrstagung der Sektion Atome, Moleküle, Quantenoptik und Photonik (SAMOP), 05.-10.03.2023, Hannover, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35918


Curvilinear Micromagnetism, From Fundamentals to Applications: Tubular Geometries

Landeros, P.; Otálora, J. A.; Streubel, R.; Kakay, A.

Abstract

Following the recent developments in materials science and sample fabrication magnetic nanowires and nanotubes became an intensively studied research field in magnetism. However, it should be mentioned that the driving force behind can be attributed to the theoretical, both analytical and numerical predictions of novel magnetic textures and interesting features, such as chiral domain wall motion, the Spin-Cherenkov effect or the curvature-induced magnetochiral effects in general. In this chapter, the static properties of tubular nanomagnets will be reviewed, including magnetic configurations, domain walls, their types, and energetics as well as possible reversal mechanisms. The dynamical properties section is divided into two parts. The first part will guide you through the domain wall motion related to magnetochiral effects. The second part will discuss the general aspects of spin-wave propagation. Aspects, being static or dynamic, related to magnetochiral effects or curvature and topology will be addressed mostly. For those interested in a summary of experimental methods to fabricate tubular samples, an overview of all possible techniques one can use to characterize or measure magnetic tubes, or in a guide through all the analytical and numerical formalism developed to investigate the static and dynamic properties of magnetic nanotubes, we kindly ask to read these recently published excellent books by M. Vázquez [1, 2].

Keywords: curvilinear magnetism; nanotubes; domain walls; spin waves

  • Book chapter
    Denys Makarov and Denis Sheka: Curvilinear Micromagnetism, From Fundamentals to Applications, Dresden: Springer Nature, 2022, 978-3-031-09085-1
    DOI: 10.1007/978-3-031-09086-8

Permalink: https://www.hzdr.de/publications/Publ-35917


Detectability of anatomical changes with prompt-gamma imaging: First systematic evaluation of clinical application during prostate-cancer proton therapy

Berthold, J.; Pietsch, J.; Piplack, N.; Khamfongkhruea, C.; Thiele, J.; Hölscher, T.; Janssens, G.; Smeets, J.; Traneus, E.; Löck, S.; Stützer, K.; Richter, C.

Abstract

Purpose: The development of online-adaptive proton therapy (PT) is an essential requirement to overcome limitations encountered by day-to-day variations of the patient anatomy. Range verification could play an essential role in an online feedback loop for the detection of treatment deviations such as anatomical changes. Here, we present results of the first systematic patient study regarding the detectability of anatomical changes by a prompt-gamma imaging (PGI) slit-camera system.

Materials & Methods:  For 15 prostate-cancer patients, PGI measurements were performed during 105 fractions (201 fields) with in-room control CTs. Field-wise doses on control CTs were manually classified whether showing relevant or non-relevant
changes. Spot-wise ground-truth range shift information was retrieved by integrated depth-dose (IDD) analyses serving for a field-wise ground-truth classification. Spot-wise PGI-based range shifts were initially compared to corresponding IDD shifts and then combined in a PGI-model to match the field-wise IDD-based classification. This model was optimized and tested for a sub-cohort of 10 and 5 patients, respectively.

Results:  The correlation between PGI and IDD range shifts was high, ρ_pearson = 0.67 (p<0.01). Field-wise binary PGI-classification resulted in an area under the curve (AUC) of 0.72 and 0.80 for training and test cohort, respectively. The model detected relevant anatomical changes in the independent test cohort with a sensitivity and specificity of 74% and 79%, respectively.

Conclusion:  For the first time, evidence of the detection capability of anatomical changes in prostate-cancer PT from clinically acquired PGI data is shown. This emphasizes the benefit of PGI-based range verification and demonstrates its potential for online-adaptive PT.

Keywords: proton therapy; range verification; treatment verification; prompt-gamma imaging; prostate cancer; automated classification; inter-fractional changes

Involved research facilities

  • OncoRay

Permalink: https://www.hzdr.de/publications/Publ-35916


Geometry-driven effects in curvilinear spin chains with antiferromagnetic exchange

Pylypovskyi, O.

Abstract

Curvilinear magnetism is a research field studying curved nanowires and thin films with anisotropic and chiral magnetic responses are tailored by the geometry. The contemporary theories reach the level of maturity for ferromagnets [1,2]. At the same time, very little is done for antiferromagnets (AFMs), which are promising for low-power consuming and high-speed spintronic devices [2].

The simplest systems uncovering the specific features of AFM exchange in curvilinear geometries are spin chains, which can be arranged along plane and space curves. If the dipolar interaction is the dominating source of anisotropy, it renders the chain as the hard-axis AFM with the anisotropy axis along the tangential direction. There are two families of effects of geometry stemming from exchange. The first ones come from the spatial gradients of the Néel vector. A direction of local twists and bends of the chain manifests itself as the geometry-driven DMI and contributes to the tensor of total anisotropy [3]. As a consequence, the curvilinear AFM spin chain along space curve with exchange and dipolar interaction behaves as the chiral helimagnet, with the helimagnetic transition determined by the curvature and torsion of the curve. Such a chain arranged along the plane curve has the one ground state with the equilibrium Néel ordering perpendicular to the curve plane. In both cases, the easy axis of anisotropy arises from the exchange [3]. Localized bends of the curve also lead to the pinning of domain walls [4]. In addition to the chiral and anisotropic effects, the locally broken spatial symmetry of the AFM chain leads to the geometry-driven weak ferromagnetism. The strength of the emergent magnetization scales linearly with the curvature and torsion [5].

A unit cell of AFM contains a few spins. For the case of the single-ion anisotropy, its direction is varyring within the unit cell. This leads to the specific contributions to the magnetic responses stemming from anisotropy, such as an anisotropic term which mixes the tangential and normal components of the Néel and ferromagnetic order parameters as the DMI of longitudinal symmetry [5]. This can be of importance for non-collinear textures in one-dimensional AFMs, where the finite magnetization appears at inhomogeneity of the Néel vector.

[1] P. Fischer et al, APL Mater., 8, 010701 (2020); R. Streubel et al. Journal of Applied
Physics, 129, 210902 (2021)
[2] D. Makarov et al, Adv. Mater., 34, 2101758 (2022)
[3] O. Pylypovskyi, D. Kononenko et al, Nano Lett., 20, 8157–8162 (2020)
[4] K. Yershov, Phys. Rev. B, 105, 064407 (2022)
[5] O. Pylypovskyi et al, App. Phys. Lett., 118, 182405 (2021)

Keywords: antiferromagnetism; spin chains; curvilinear magnetism

  • Lecture (Conference)
    AIM 2023 Advances in Magnetics, 15.-18.01.2023, Moena, Italy

Permalink: https://www.hzdr.de/publications/Publ-35915


UAV magnetics for underwater targets in Rogaland anorthosite province, Norway

Madriz Diaz, Y. C.; Lee, M.; Lorenz, S.; McEnroe, S.; Gloaguen, R.

Abstract

Drone-based aeromagnetic surveys are a cost- and time-effective tool for high resolution mapping of unexposed geological structures. This technology is particularly advantageous for areas where it is difficult or impossible to conduct ground-based surveys such as beneath water bodies. Uncrewed aerial vehicles (UAVs) are robust and versatile platforms adapted to ensure precise and more controlled surveying at different scales in operational conditions. During the last years we have been developing and testing a series of workflows to efficiently acquire and process aeromagnetic data. Using an inhouse developed python toolbox we automate the data quality assessment on-site and implement a data-driven decision making algorithm to optimise the survey operation. With low altitude flights (<12m) and tight line spacings we ensure the acquisition of high-quality, detailed maps facilitating the geophysical interpretation of small-scale geological features.

To demonstrate the potential of our approach we present a demanding study area on a lake in Rogaland, Norway with low GPS coverage (valley), high magnetic gradients affecting the navigation system of the drone and non-ideal weather conditions to showcase the advantages of UAV magnetic surveys.

Keywords: Uncrewed aircraft systems; Unmanned aerial systems; Magnetic surveys; Fluxgate magnetometer; Airborne surveying

  • Invited lecture (Conferences)
    South African Geophysical Association’s 17th Biennial Conference & Exhibition, 28.11.-01.12.2022, Sun City, South Africa

Permalink: https://www.hzdr.de/publications/Publ-35914


40 years after Aitchison's article "The statistical analysis of compositional data". Where we are and where we are heading

Coenders, G.; Egozcue, J. J.; Facevicova, K.; Navarro-Lopez, C.; Palarea-Albadalejo, J.; Pawlowsky-Glahn, V.; Tolosana Delgado, R.

Abstract

The year 2022 marked 40 years since Aitchison published the article "The statistical analysis of compositional data". It is considered to be the foundation of contemporary compositional data analysis. It is time to review what has been accomplished in the field and what needs to be addressed. Astonishingly enough, many aspects seen as challenging in 1982 continue to lead to fruitful scholarly work. We commence with a bibliometric study, and continue with some hot topics such as multi-way compositions, compositional regression models, dealing with zero values, non-logratio transformations, new application fields, and a number of current loose ends. Finally, a tentative future research agenda is outlined.

Keywords: Compositional Data (CoDa); logratios; Aitchison geometry; multi-way compositions; zero replacement; compositional regression

Permalink: https://www.hzdr.de/publications/Publ-35913


Using Frontier for CAAR Plasma-In-Cell (PIC) on GPU application

Steiniger, K.; Debus, A.; Chandrasekaran, S.

Abstract

Presentation of PIConGPU at DOE Booth at Supercomputing 2022

Keywords: PIConGPU; particle-in-cell; laser plasma accelerators

  • Poster
    The International Conference for High Performance Computing, Networking, Storage, and Analysis, 13.-18.11.2022, Dallas, Texas, United States of America

Permalink: https://www.hzdr.de/publications/Publ-35912


Development of a new quantum trajectory molecular dynamics framework

Svensson, P.; Campbell, T.; Graziani, F.; Moldabekov, Z.; Lyu, N.; Richardson, S.; Vinko, S. M.; Gregori, G.

Abstract

An extension to the wave packet description of quantum plasmas is presented, where the wave packet can be elongated in arbitrary directions. A generalised Ewald summation is constructed for the wave packet models accounting for long-range Coulomb interactions and fermionic effects are approximated by purpose-built Pauli potentials, self-consistent with the wave packets used. We demonstrate its numerical implementation with good parallel support and close to linear scaling in particle number, used for comparisons with the more common wave packet employing isotropic states. Ground state and thermal properties are compared between the models with differences occurring primarily in the electronic subsystem. Especially, the electrical conductivity of dense hydrogen is investigated where a 15% increase in DC conductivity can be seen in our wave packet model compared to other models.

Keywords: wave packet molecular dynamics; warm dense matter; Pauli potential

Permalink: https://www.hzdr.de/publications/Publ-35911


Optimizing laser plasma acceleration performance for proton beams beyond the 100 MeV frontier

Ziegler, T.; Assenbaum, S.; Bernert, C.; Brack, F.-E.; Cowan, T.; Dover, N. P.; Garten, M.; Gaus, L.; Göthel, I.; Kiriyama, H.; Kluge, T.; Kon, A.; Kraft, S.; Kroll, F.; Metzkes-Ng, J.; Nishuichi, M.; Reimold, M.; Rehwald, M.; Schlenvoigt, H.-P.; Umlandt, M. E. P.; Schramm, U.; Vescovi Pinochet, M. A.; Zeil, K.

Abstract

Exploiting the strong electromagnetic fields that can be supported by a laser driven compact plasma accelerator enables generation of short, high-intensity pulses of high energy ions with special beam properties. The maturation of such laser driven ion accelerators from physics experiments to turn-key sources for applications will rely on breakthroughs in both, generated beam parameters (kinetic energy, flux), as well as increased scrutiny on reproducibility, robustness, and scalability to high repetition rate.
Recent developments at the high-power laser facility DRACO-PW enabled the production of polychromatic proton beams with unprecedented stability [1]. This facilitated the first in vivo radiobiological study using a laser-driven proton source [2]. For many related advanced applications, the ability to generate proton beams with energies beyond the 100 MeV frontier at a repetition rate and in a controllable way is essential and the subject of ongoing research.
Latest experimental studies concentrated on pre-expanded plastic foil target undergoing relativistically induced transparency using linearly polarized laser pulses with peak intensities beyond 1021 W/cm2. A complex suite of particle and optical diagnostics allowed characterization of spatial and spectral proton beam parameters and the stability of this regime for best acceleration performance exceeding 100 MeV cut-off energies. Combined hydrodynamic and 3D particle-in-cell simulations helped to identify the most promising target parameter range matched to the carefully measured prevailing laser contrast conditions.

Involved research facilities

  • Draco
  • Invited lecture (Conferences)
    Garchinger Maier-Leibnitz Kolloquium, 15.12.2022, Garching, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35910


Alternating Screening And Higher Harmonics In Complex Plasmas

Moldabekov, Z.

Abstract

Modeling properties of strongly correlated many-particle systems are of both fundamental and practical importance. At the same time, generating and probing these properties is challenging. To this end, laboratory model systems play a central role in studying correlated many-particle phenomena. In this presentation, we focus on a specific laboratory model system – dusty plasmas – to model collective particle behavior under controlled conditions. Thereby, we push the frontier of dusty plasma physics by predicting the generation of high harmonics in dusty plasmas with alternating screening length [1]. We found a simple phenomenological expression for the dispersion relation of higher harmonics. Moreover, it is shown that the periodically alternating screening causes a self-conjugate state with negative refraction. As the application, we speculate that our findings can serve as a test bed for studying the fundamental physics of a self-conjugate state with negative refraction in strongly correlated systems on the kinetic level.

[1] Z. A. Moldabekov et al., Phys. Rev. Research 3, 043187 (2021)

Keywords: strongly correlated many-particle systems; plasma physics; generation of high harmonics

  • Invited lecture (Conferences) (Online presentation)
    6th Asia Pacific Conference on Plasma Physics, 09.-14.10.2022, virtual, virtual

Permalink: https://www.hzdr.de/publications/Publ-35909


Distortions in focusing laser pulses due to spatio-temporal couplings – An analytic description

Steiniger, K.; Dietrich, F.; Albach, D.; Bussmann, M.; Irman, A.; Löser, M.; Pausch, R.; Püschel, T.; Sauerbrey, R.; Schöbel, S.; Schramm, U.; Siebold, M.; Zeil, K.; Debus, A.

Abstract

In ultra-short laser pulses, small changes in dispersion properties before the final focusing mirror can
lead to severe pulse distortions around the focus and therefore to very different pulse properties at the
point of laser-matter interaction yielding unexpected interaction results. The mapping between far and
near-field laser properties intricately depends on the spatial and angular dispersion properties as well as the
focal geometry. For a focusing Gaussian laser pulse subject to angular, spatial, and group delay dispersion,
we derive analytical expressions for its pulse-front tilt, duration, and width from a fully analytic expression
for its electric field in time-space domain. This expression is not only valid in and near the focus but along
the entire propagation distance from the focusing mirror to the focus. Together with expressions relating
angular, spatial, and group delay dispersion before focusing at an off-axis parabola to the respective values
in the pulse’s focus, these formulas are used to show in example setups that pulse-front tilts of lasers
with small initial dispersion can become several ten degrees large in the vicinity of the focus while being
small directly in the focus. The formulas derived here provide the analytical foundation for observations
previously made in numerical experiments. By numerically simulating Gaussian pulse propagation and
measuring properties of the pulse at distances several Rayleigh lengths off the focus we verified the analytic
expressions.

Keywords: pulse propagation; pulse-front tilt; laser dispersion; high-power laser; ultrafast optics

Related publications

Permalink: https://www.hzdr.de/publications/Publ-35908


Quantum linear and non-linear density response of electrons

Moldabekov, Z.

Abstract

Warm dense matter is the state of matter naturally appearing in interiors of planets and stars. In laboratory warm dense matter is generated by laser heating and shock compression. Warm dense matter is also important as a transient state on the way to ignition in inertial confinement fusion experiments. Density response properties are important for the understanding process in warm dense matter for computation of optical and transport characteristics. In this presentation, I will discuss the theoretical foundations of the linear and non-linear density response theory for warm dense matter. Going beyond theoretical formulations, the calculations based on the KS-DFT method will be presented.

Keywords: warm dense matter; non-linear response; exchange-correlation kernel

  • Invited lecture (Conferences)
    10th International Symposium "Optics & its applications", 05.-10.12.2022, Cali, Colombia

Permalink: https://www.hzdr.de/publications/Publ-35907


Material Specific Exchange-Correlation Kernel for WDM

Moldabekov, Z.

Abstract

We developed a new method that allows one to compute material specific static exchange-correlation kernel across temperature regimes using standard DFT codes and for any XC functional available in Libxc [1]. In this presentation we show the results of the static exchange-correlation kernel analysis from computations using various XC functionals for dense electron gas and warm dense hydrogen. By comparing the data to the exact QMC results, we are able to understand the effect of thermal excitations and density inhomogeneity on the exchange-correlation kernel. Moreover, we discuss the results of the analysis of the accuracy of the commonly used exchange-correlation (XC) functionals for warm dense matter simulations [2-4]. The analysis is performed by comparing highly accurate path-integral quantum Monte-Carlo (QMC) data with KS-DFT results. Finally, a new methodology for the investigation of the non-linear static density response of WDM based on the KS-DFT method is presented [5].

[1] Zhandos A. Moldabekov, Maximilian Böhme, Jan Vorberger, David Blaschke, Tobias Dornheim, arXiv:2209.00928 (2022).
[2] Z. Moldabekov, T.Dornheim, M. Böhme, J. Vorberger, A. Cangi, The Journal of Chemical Physics 155, 124116 (2021).
[3] Z. Moldabekov, T.Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105, 035134 (2022).
[4] Z. A. Moldabekov, T. Dornheim, G. Gregori, F. Graziani, M. Bonitz, A. Cangi, SciPost Phys. 12, 062 (2022).
[5] Z.Moldabekov, J. Vorberger, T. Dornheim, Journal of Chemical Theory and Computation 18, 2900–2912 (2022).

Keywords: warm dense matter; hybrid functionals; KS-DFT; exchange-correlation kernel

  • Lecture (Conference)
    10 th Workshop on High Pressure, Planetary and Plasma Physics (10HP4), 28.-29.09.2022, Brussels, Belgium

Permalink: https://www.hzdr.de/publications/Publ-35906


Ab Initio Static Exchange–Correlation Kernel From DFT

Moldabekov, Z.

Abstract

The KS-DFT is the standard method to model the electronic structure due to its accuracy and computational efficiency. The reduction in computation cost compared to other ab initio methods is due to a formally exact mapping onto an effective single-electron problem. DFT calculations of a various material properties require as input the so-called exchange—correlation (XC) kernel. Yet, little is known about the actual kernel of real materials, and hitherto no reliable universal way to compute it has been known. In this work, we present a new methodology to compute the static XC-kernel of any material; which needs no external input apart from the usual XC-functional. The application of the method is demostrated for the uniform electron gas and hydrogen. Moreover, we consider both ambient conditions and the warm-dense matter (WDM) parameters. In addition, our analysis of the static XC-kernel gives us valuable new insights into the construction of the XC-functionals for the application at WDM regime.

  • Lecture (Conference)
    Multiscale Modeling of Matter under Extreme Conditions, 11.-16.09.2022, Görlitz, Germany

Permalink: https://www.hzdr.de/publications/Publ-35905


Analyzing XC functionals for electronic structure calculations at WDM parameters

Moldabekov, Z.; Dornheim, T.; Cangi, A.; Böhme, M.; Vorberger, J.

Abstract

In this presentation we discuss the results of the analysis of the accuracy of the commonly used exchange-correlation (XC) functionals for warm dense matter simulation [1,2]. The analysis is performed by comparing the path-integral quantum Monte-Carlo (QMC) data with KS-DFT results. The relative deviation of the total density from the reference data is reported for different XC functionals in the case of the inhomogeneous electron gas. Furthermore, a new methodology for the investigation of the non-linear static density response WDM based on KS-DFT method is presented [3]. The results are verified by comparing to the QMC data when thermal temperature is equal to the Fermi temperature. New results for partially and strongly degenerate electrons are presented. Finally, we present the results of the analysis of the electronic local field correction as computed using various XC functionals. By comparing the data to the exact QMC results, we are able to understand the effect of the thermal excitations on XC functional.

[1] Z. Moldabekov, T.Dornheim, M. Böhme, J. Vorberger, A. Cangi, The Journal of Chemical Physics 155, 124116 (2021).
[2] Z. Moldabekov, T.Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105, 035134 (2022).
[3] Z.Moldabekov, T. Dornheim, J. Vorberger, Journal of Chemical Theory and Computation (2022).

Keywords: warm dense matter; exchange-correlation functionals; KS-DFT

  • Lecture (Conference)
    Strongly Coupled Coulomb Systems (SCCS), 24.-29.07.2022, Goerlitz, Germany

Permalink: https://www.hzdr.de/publications/Publ-35904


QED.jl - Strong-field particle physics code

Hernandez Acosta, U.; Steiniger, K.; Jungnickel, T.; Bussmann, M.

Abstract

The collision of relativistic electron beams with highly intense, highly energetic and
short-pulsed light will give deep insights into the interactions of electromagnetic fields
and matter at extreme scales. Experimentally, those collisions might be addressed
at upcoming projects like HIBEF 2.0 at the EuropeanXFEL, SYLOS at ELI-ALPS or
LCLS-II at SLAC, to name a few. The precise theoretical description of such collision
experiments is very challenging and not fully covered by the currently available tools,
known from particle physics. We develop the open-source software library QED.jl,
which targets those gaps by
Modelling of (non-linear) Quantum Processes
providing new developments of
higher-order
pair production
state-of-the-art modelling tools w.r.t.
inelastic scattering
Processes
and annihilation
strong-field physics. This includes

  • Modelling of particle physics
processes: calculation of Matrix
element and cross section
  • Monte-Carlo event generation:
Parallelised drawing of samples
from multivariate distributions,
  • Multivariate integration:
Algorithms for highly oscillatory
problems and Monte-Carlo
integration for Total cross sections
Monte-Carlo Event-Generator
Large-Scale Simulation
Classical
Processes
QED.jl is written in the Julia
Laser-Matter Collision Experiments
programming language, which
opens up the usage of modern
language features like just-in-time compilation, multiple-dispatch and meta-
programming to attain efficiency in execution time, where the code is still easy to use
and develop. Consequently, based on the computational demanding tasks given by
the physics use case, necessary advances w.r.t. distributed computing are planed to
be developed using Julia:
  • Task scheduling using directed acyclic graphs:
Generation of compute graphs from specific physical models, and optimisation of
the evaluation of such graphs in parallel,
  • Code injection:
Extension of Julia compile workflow by injecting problem specific C++ code,
  • Hardware-agnostic parallelisation:
Kernel abstractions in Julia, e.g. by using ALPAKA

Keywords: SFQED; QED.jl

  • Poster
    Big data analytical methods for complex systems, 06.-07.10.2022, Wroclaw, Polska

Permalink: https://www.hzdr.de/publications/Publ-35903


Excitations of an Inhomogeneous Electronic System: From Ambient Conditions to Warm Dense Matter

Moldabekov, Z.

Abstract

Warm dense matter (WDM) is the state of matter at high pressures and temperatures. WDM is
relevant both for practical applications and for fundamental science. The practical significance is
due to the generation of the WDM state in experiments on nuclear fusion and the creation of new
materials under extreme conditions. From the point of view of fundamental science, the relevance
of WDM is due to the extreme conditions in the interiors of planets and stars.
Many questions regarding the interplay of quantum degeneracy, thermal excitations, and strong
correlations effects in WDM remain open. To solve this problem, we use an externally perturbed
WDM to investigate how electronic structure and excitations are affected by thermal excitations
and density inhomogeneities. The results are reported in our recent articles [1-4], where we
presented: a study of the quality of various exchange-correlation functionals in the KS-DFT method
[1,2]; the change in electronic excitations due to strong inhomogeneity and thermal effects [3]; and
a new KS-DFT based methodology for the investigation of the non-linear response of electrons
across temperature regimes relevant for WDM [4].

[1] Z. Moldabekov, T. Dornheim, M. Boehme, J. Vorberger, A. Cangi, J. Chem.Phys. 155 (2021)
124116.
[2] Z. Moldabekov, T. Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105 (2022) 035134.
[3] Z. Moldabekov, T. Dornheim, A. Cangi, Sci. Rep. 12 (2022) 1093.
[4] Z. Moldabekov, J. Vorberger, T. Dornheim, J. Chem. Theory Comput. 18 (2022) 2900

Keywords: warm dense matter; extreme conditions; non-linear response

  • Invited lecture (Conferences)
    UWr-HZDR-CASUS International Conference on Advanced Systems Research CASUSCON, 11.-15.07.2022, Wrocław, Poland

Permalink: https://www.hzdr.de/publications/Publ-35902


Inhomogeneous electron gas under warm dense conditions

Moldabekov, Z.; Dornheim, T.; Vorberger, J.

Abstract

Warm dense matter (WDM) is a state of matter with parameters between solids and
dense plasmas. WDM is characterized by the relevance of quantum degeneracy, thermal
excitations, and strong correlations. Many questions regarding the interplay of these
effects in WDM remain open. In this paper, we use an externally perturbed electron gas
to investigate how electronic structure and excitations are affected by thermal excitations
and density inhomogeneities. The results are reported in our recent articles [1-4]. We
present a study of the quality of various exchange-correlation functionals in the KS-DFT
method [1,2]. In addition, we show how electronic excitations change due to strong
inhomogeneity and thermal effects [3]. Based, on these results, we present a new KS-DFT
based methodology for the investigation of the non-linear response of electrons across
temperature regimes relevant for WDM [4].

References
[1] Z. Moldabekov, T.Dornheim, M. Boehme, J. Vorberger, A. Cangi, The Journal of Chem-
ical Physics 155, 124116 (2021).
[2] Z. Moldabekov, T.Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105, 035134 (2022).
[3] Z. Moldabekov, T.Dornheim, A. Cangi, Scientific Reports 12, 1093 (2022)
[4] Z.Moldabekov, J. Vorberger, T. Dornheim, Journal of Chemical Theory and Computation,
accepted for publication (2022); arXiv:2201.01623.

Keywords: warm dense matter; exchange-correlation functionals; non-linear response

  • Lecture (Conference)
    The 13th International Conference on High Energy Density Laboratory Astrophysics HEDLA 2022, 23.-27.05.2022, Lisbon, Portugal

Permalink: https://www.hzdr.de/publications/Publ-35901


Accompanying the hybrid LPWFA experiment campaign with a computer simulation campaign: What we model, what we learn, and where we need to become better

Steiniger, K.; Pausch, R.; Bastrakov, S.; Chang, Y.-Y.; Couperus Cabadağ, J. P.; Irman, A.; Köhler, A.; Kurz, T.; Schöbel, S.; Widera, R.; Schramm, U.; Zarini, O.; Debus, A.; Bussmann, M.; Heinemann, T.; Assmann, R. W.; Martinez De La Ossa, A.; Hidding, B.; Gilljohann, M. F.; Ding, H.; Götzfried, J.; Schindler, S.; Döpp, A.; Karsch, S.; Kononenko, O.; Raj, G.; Corde, S.

Abstract

The Hybrid Collaboration, a joint undertaking by HZDR, DESY, University of Strathclyde, LMU, and LOA, performed hybrid LPWFA experiments which utilize electron bunches from a laser wakefield accelerator (LWFA) as drivers of a plasma wakefield stage (PWFA) to demonstrate the feasibility of compact PWFAs serving as a test bed for the efficient investigation and optimization of PWFAs and their development into brightness boosters. To better understand the microscopic, nonlinear dynamic of these accelerators, the experiments were accompanied by 3D3V particle-in-cell simulations using PIConGPU.

Here, we present insights into the dynamics of the hybrid LPWFA that we gained from start-to-end simulations of the experimental setup at HZDR.
These regard electron injections due to hydrodynamic shocks, beam self-modulation and breakup, and cavity elongation - all backed-up by synthetic diagnostics that allow direct comparison with experimental measurements.
We discuss our approach to model these synthetic diagnostics directly within the PIConGPU simulation as well as modelling certain aspects of the experimental setup, such as the drive laser. Continuing this, the talk highlights a few recent technical advances in PIConGPU that enable better modelling of the micro-physics, experiment conditions, or signals of experiment diagnostics.

Keywords: laser; plasma; laser wakefield acceleration; LPWFA; particle-in-cell; PIConGPU; digital twin

  • Open Access Logo Invited lecture (Conferences)
    Advanced Accelerator Concepts Workshop, 06.-11.11.2022, Hauppauge, New York, United States of America

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Permalink: https://www.hzdr.de/publications/Publ-35900


[18F]FLUDA – A promising PET probe for the non-invasive assessment of the A2A adenosine receptor

Lai, T. H.; Toussaint, M.; Gündel, D.; Dukic-Stefanovic, S.; Teodoro, R.; Sattler, B.; Wenzel, B.; Schröder, S.; Moldovan, R.-P.; Sabri, O.; Brust, P.; Kopka, K.; Deuther-Conrad, W.

Abstract

Introduction: The A2A adenosine receptor (A2AAR) is expressed in brain, vasculature and immune cells. According to the alterations of the A2AAR expression in multiple diseases, it is a highly attractive diagnostic and therapeutic target. We developed the A2AAR-specific PET radiotracer [18F]FLUDA and investigated it in healthy mice and piglets, in a rotenone-based mouse model of Parkinson’s disease (RMMPD) and in transgenic mice overexpressing the human A2AAR in heart (TG) [1 3].

Methods: On the basis of a one-pot two-step radiofluorination procedure, a remotely controlled automated radiosynthesis of [18F]FLUDA using the TRACERlab FX2N synthesis module was developed. In vitro autoradiography was performed with cryosections of tissue from animal models. In vivo stability was investigated in mouse by radio-HPLC analyses of blood plasma and brain homogenates. The biodistribution was investigated by dynamic PET/MR studies in healthy mice and piglets under control and blocking conditions (vehicle vs. blocking with 2.5 mg/kg tozadenant and/or 1.0 mg/kg istradefylline) and in both mouse models. The binding potential (BPND) in vivo was calculated using the simplified reference tissue modelling with the cerebellum as reference region. A single dose acute toxicity study was performed in Wistar rats according to the ICH guideline M3(R2). PET-derived radiation dosimetry was estimated in piglets.

Results: A reliable and reproducible procedure for the automated production of [18F]FLUDA was successfully established (Fig. 1A) [4]. In vitro autoradiography revealed highly selective binding and high affinity of [18F]FLUDA towards the A2AAR of the three species (KD values 0.7-5.9 nM, Fig. 1B). At 15 min after i.v. injection of [18F]FLUDA in mice, the parent fraction accounted for about 100% in brain and 71% in plasma. PET studies confirmed the specific binding of [18F]FLUDA in vivo to the striatal A2AAR in mice and piglets (BPND=3.9 and 1.3, Fig. 1C). The availability of A2AAR in the Parkinson’s disease model was not significantly different from the control. The cardiac overexpression of human A2AAR resulted in a significantly higher accumulation of activity compared to control (1.4-fold higher ratio of the area-under-the curves obtained for myocard and blood, 1-10 min p.i., p=0.001). Toxicity studies revealed no adverse effects up to a dose of 30 µg/kg of FLUDA (approx. 4,000-fold of expected human dose). The estimated effective dose of [18F]FLUDA in humans is 16.4 µSv/MBq, which is in the range of other 18F-labeled radiotracers [5].

Conclusion: We have demonstrated that [18F]FLUDA is suitable for the determination of the availability of A2AAR in the brain in vitro and in vivo. No safety concerns are expected upon administration of [18F]FLUDA according to toxicity and dosimetry data. These results encourage the clinical translation of [18F]FLUDA.

Acknowledgement: This work (project no. 100226753) was funded by the European-Regional-Development-Fund (ERDF) and Sächsische-Aufbaubank (SAB).

References: [1] T.H. Lai and M. Toussaint et al., EJNNMI 2021, 48:2727–2736; [2] D. Gündel and M. Toussaint, Pharmaceuticals 2022, 15; [3] D. Gündel et al., Int. J. Mol. Sci. 2022, 23, 1025; [4] T.H. Lai et al., J. Label. Compd. Radiopharm. 2022, 65:162–166; [5] B. Sattler et al., J. Nucl. Med. 2020, 61:1014.

Keywords: FLUDA; Fluorine-18; A2A adenosine receptor; PET

  • Poster
    iSRS 2023 - 25th International Symposium of Radiopharmaceutical Sciences, 22.-26.05.2023, Honolulu, Hawaii

Permalink: https://www.hzdr.de/publications/Publ-35899


Assessing the accuracy of hybrid exchange-correlation functionals for the density response of warm dense electrons

Moldabekov, Z.; Lokamani, M.; Vorberger, J.; Cangi, A.; Dornheim, T.

Abstract

We assess the accuracy of common hybrid exchange-correlation (XC) functionals (PBE0, PBE0-1/3, HSE06, HSE03, and B3LYP) within Kohn-Sham density functional theory (KS-DFT) for the harmonically perturbed electron gas at parameters relevant for the challenging conditions of warm dense matter. Generated by laser-induced compression and heating in the laboratory, warm dense matter is a state of matter that also occurs in white dwarfs and planetary interiors. We consider both weak and strong degrees of density inhomogeneity induced by the external field at various wavenumbers. We perform an error analysis by comparing to exact quantum Monte-Carlo results. In the case of a weak perturbation, we report the static linear density response function and the static XC kernel at a metallic density for both the degenerate ground-state limit and for partial degeneracy at the electronic Fermi temperature. Overall, we observe an improvement in the density response for partial degeneracy when the PBE0, PBE0-1/3, HSE06, and HSE03 functionals are used compared to the previously reported results for the PBE, PBEsol, LDA, AM05, and SCAN functionals; B3LYP, on the other hand, does not perform well for the considered system. Together with the reduction of self-interaction errors, this seems to be the rationale behind the relative success of the HSE03 functional for the description of the experimental data on aluminum and liquid ammonia at WDM conditions.

Keywords: warm dense matter; hybrid functionals; Hartree-Fock

Related publications

Permalink: https://www.hzdr.de/publications/Publ-35898


Non-empirical mixing coefficient for hybrid XC functionals from analysis of the XC kernel

Moldabekov, Z.; Lokamani, M.; Vorberger, J.; Cangi, A.; Dornheim, T.

Abstract

We present an analysis of the static exchange-correlation (XC) kernel computed from hybrid functionals with a single mixing coefficient such as PBE0 and PBE0-1/3. We break down the hybrid XC kernels into the exchange and correlation parts using the Hartree-Fock functional, the exchange-only PBE, and the correlation-only PBE. This decomposition is combined with exact data for the static XC kernel of the uniform electron gas and an Airy gas model within a subsystem functional approach. This gives us a tool for the nonempirical choice of the mixing coefficient at ambient and extreme conditions. Our analysis provides physical insights into the effect of the variation of the mixing coefficient in hybrid functionals, which is of immense practical value. The presented approach is general and can be used for other type of functionals like screened hybrids.

Keywords: warm dense matter; hybrid functionals; Hartree-Fock

Related publications

Permalink: https://www.hzdr.de/publications/Publ-35897


Materials Research in High Magnetic Fields

Wosnitza, J.

Abstract

Für diesen Vortrag hat keine Kurzfassung vorgelegen.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences)
    UWr-CASUS-HZDR International Conference (CASUSCON) on Advanced Systems Research, 11.-15.07.2022, Wroclaw, Polen

Permalink: https://www.hzdr.de/publications/Publ-35896


Research and technology at the Dresden High Magnetic Field Laboratory (HLD)

Herrmannsdörfer, T.

Abstract

The Dresden High Magnetic Field Laboratory (Hochfeld-Magnetlabor Dresden, HLD) is a user facility for experiments at extreme sample conditions and an institute of the HZDR as well. The HLD provides access to magnets and measurement equipment that allows for experiments up to the feasibility limits of the magnetic-field scale. In particular, research on quantum condensed matter with novel electronic or magnetic properties is the central research area at HLD. As a central task, the HLD develops and operates world-class pulsed high-field magnets to make them available for excellent research by external and in-house users. It is the only installation in Germany and one of the four large user facilities in Europe which operate high-field magnets in combination with advanced measurement techniques; the other partner facilities are located in Grenoble, Nijmegen and Toulouse. The close cooperation between these high-field laboratories has been formalized by the foundation of the European Magnetic Field Laboratory (EMFL). Via a peer-reviewed proposal system, centrally managed by EMFL, the HLD provides leading-edge and in part unique experimental capabilities allowing for high-resolution measurement techniques for materials research in state-of-the-art pulsed magnets reaching top-level field strengths. All these experimental techniques are available over a broad temperature range too, most even down to millikelvin temperatures. The combination of infrared radiation produced by free-electron lasers of the neighboring superconducting electron accelerator ELBE with pulsed-field magnets is world unique. At HLD, a technology-development program for nondestructive pulsed magnets and pulsed power supplies is being carried out allowing to provide the highest possible fields for internal and external users. Various types of pulsed magnets have been designed and are in operation with recently realized dual-coil systems reaching magnetic fields of 85 and 95 T, available for users. Furthermore, a development program for pulsed-power supplies providing electrical currents of several 100 kA as well as electrical power of several GW is in work. These technological activities which make also use of modern simulation methods are under way for realizing a dedicated power supply at the European XFEL (HIBEF project) and for industrial applications, e.g. for electromagnetic pulse forming, joining, and welding as well as for medical engineering and hydrogen liquefaction. In cooperation with industrial and EMFL partners, the HLD will develop a new generation of all-superconducting high-field coils.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences)
    Workshop “Transfer to Industry” - COST Action MAGNETOFON - Ultrafast opto-magneto-electronics for non-dissipative information technology, 07.06.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35895


Wie kann man Selten Erd Elemente nachhaltiger (zurück)gewinnen?

Daumann, L.; Lederer, F.

Abstract

Gemeinsamer Beitrag in der Umweltzeitung zu biologischen Wegen der nachhaltigen Rückgewinnung von Selten Erd Elementen.

Keywords: Lanmodulin; Peptide; Biokollektoren

  • Umweltzeitung 30(2023), 12-13
    ISSN: 0948-1370 H 13873F

Permalink: https://www.hzdr.de/publications/Publ-35894


Biomolecular Toolbox for Resource Recovery

Lederer, F.

Abstract

Presentation of the biomolecular toolbox of the biotechnology department and the BioKollekt research.

Keywords: Peptides; Biotensides; Siderophores; Organic acids; resource recovery

  • Lecture (others)
    2nd Workshop of the topic RESOURCE AND ENERGY EFFICIENCY, 07.-08.12.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35893


Why system and multi-disciplinarity thinking is key to circularity

Lederer, F.; Dirlich, S.; Pereira, T.; Mütze, T.; Raatz, S.; Gutzmer, J.

Abstract

Presentation of research approaches at HIF towards a circular economy

Keywords: circular economy; recycling; battery recycling; biobased recycling tools

  • Invited lecture (Conferences)
    1st Continental Automotive Sustainability Conference, 20.10.2022, Wiesbaden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35892


Added value from residues: Potential and relevance of a circular economy

Lederer, F.

Abstract

Presentation of circular economy approaches at HIF

Keywords: circular economy; sustainability; recycling; biobased recycling tools

  • Invited lecture (Conferences)
    4. Sächsisch-Polnischer Innovationstag, 15.-16.09.2022, Wroclaw, Polen

Permalink: https://www.hzdr.de/publications/Publ-35891


ENERGY TRANSITION Towards a more sustinable energy supply

Lederer, F.; Dirlich, S.

Abstract

Nachhaltigkeit und Natur: Der Fokus des Clusters liegt auf der Frage, wie eine Transition hin zu einer klimafreundlichen Energieversorgung nachhaltig gelingen kann, da diese zwar CO2-Neutralität garantiert, dabei aber auf Ressourcen - wie beispielsweise seltene Erden - angewiesen ist, die selbst wiederum unter fraglichen Bedingungen abgebaut werden und dabei andere bedenkliche Abhängigkeitsverhältnisse entstehen lassen. Wir möchten die Frage aufgreifen, wie mit dem Dilemma umgegangen werden kann, dass endliche natürliche Ressourcen mit einem prinzipiell unendlichen Wachstumsstreben einer profitorientierten Wirtschaft konfrontiert sind. Mit anderen Worten:Wie können wir dem Klimawandel begegnen und den Übergang zu einer klimaneutralen Wirtschaft meistern, ohne auf die Ausbeutung von Menschen und
Raubbau an der Natur zurückgreifen zu müssen?

Keywords: Circular economy; energy transition; rare earth elements; club of rome; Biorecycling

  • Invited lecture (Conferences) (Online presentation)
    Deutsch-baltische Konferenz, 27.-30.10.2022, Riga, Lettland

Permalink: https://www.hzdr.de/publications/Publ-35890


Transient Laser-Induced Breakdown of Dielectrics in Ultrarelativistic Laser-Solid Interactions

Bernert, C.; Assenbaum, S.; Bock, S.; Brack, F.-E.; Cowan, T.; Curry, C. B.; Garten, M.; Gaus, L.; Gauthier, M.; Gebhardt, R.; GöDe, S.; Glenzer, S. H.; Helbig, U.; Kluge, T.; Kraft, S.; Kroll, F.; Obst-Huebl, L.; Püschel, T.; Rehwald, M.; Schlenvoigt, H.-P.; Schoenwaelder, C.; Schramm, U.; Treffert, F.; Vescovi Pinochet, M. A.; Ziegler, T.; Zeil, K.

Abstract

For high-intensity laser-solid interactions, the absolute density and surface density gradients of the target at the arrival of the ultra-relativistic laser peak are critical parameters. Accurate modeling of the leading edge-driven target pre-expansion is desired to strengthen the predictive power of associated computer simulations. The transition from an initial solid state to a plasma state, i.e., the breakdown of the solid, defines the starting point of the subsequent target pre-expansion. In this work, we report on the time-resolved observation of transient laser-induced breakdown (LIB) during the leading edge of high-intensity petawatt-class laser pulses with peak intensities of up to 5.7 × 10^21 W/cm^2 in interaction with dielectric cryogenic hydrogen jet targets. LIB occurs much earlier than what is typically expected following the concept of barrier suppression ionization. The observation is explained by comparing a characterization study of target
specific LIB thresholds with laser contrast measurements. The results demonstrate the relevance of the laser pulse duration dependence of LIB for high-intensity laser-solid interactions. We provide an effective approach to determine the onset of LIB and thereby the starting point of target pre-expansion in other laser-target systems.

Keywords: High intensity laser-plasma interactions; High-energy-density plasmas; Laser driven ion acceleration; Laser-plasma interactions; Plasma production and heating by laser beams; Femtosecond laser irradiation; Laser ablation; Optical plasma measurements; Photoionization; Ultrafast femtosecond pump probe

Involved research facilities

  • Draco

Permalink: https://www.hzdr.de/publications/Publ-35889


Characterization of Phage Display Derived Phage Clones and Peptides for the Recovery of Valuable Metal Ions from Low Concentrated Water Streams

Matys, S.; Schönberger, N.; Boelens, P.; Lederer, F.; Pollmann, K.

Abstract

The long-term safeguarding of material resources is one of the current major economic challenges facing all industrialized nations. In particular, industrially relevant chemical elements, which are required for increasingly complex high technologies, are subject to a high supply risk [1]. For the Member States of the European Union, the Commission already compiled a list of supply-critical materials and an action plan for the implementation of a circular economy several years ago [2]. Low-resource countries such as Germany must focus more and more on the development of secondary raw material sources, effective recycling and new, environmentally friendly extraction methods. Biomolecules with metal-binding properties, especially short peptides, are particularly interesting in this respect, as they bind with high affinity and selectively, even at low concentrations [3]. We have used the commercially available bacteriophage libraries Ph.D.C7C and Ph.D.12 (New England Biolabs, Inc.) to isolate and identify specific binding peptides for several metal ions with different experimental set-ups. Here, we show how the specifically binding phage clones and isolated peptide motifs for nickel, cobalt, and gallium from Phage Surface Display (PSD) were characterized in terms of binding strength and complexation stoichiometry. For example, to specify the binding behavior, adsorption isotherms of two specifically binding phage clones - with the peptide motif CNAKHHPRC for nickel and CTQMLGQLC for cobalt - were determined on metal-loaded NTA agarose beads and compared with wild-type phage. Using different mathematical models, remarkable differences in the binding behavior of these three phage clones were found [4]. Thus, it was successfully demonstrated that the specific binding of these phage clones to chemically similar elements, such as cobalt and nickel can be verified by kinetic data. To corroborate these results, isothermal titration calorimetry studies were performed on pure synthetic peptides. The thermodynamic data also showed different binding properties for both ions. The applicability of this methodological approach was demonstrated in binding experiments with wastewater from the semiconductor industry. Selectively gallium-binding peptides have been shown to retain their binding ability after immobilization on polystyrene beads and are suitable for selective purification of complexly composed waters [5]. Our studies conducted so far indicate that PSD is generally a very suitable tool for the identification of specific binding peptides for metals in ionic form. Therefore, PSD can be considered as a platform to develop a green technology for the recovery of strategically important metals.

Keywords: phage surface display; metal recovery; peptides; adsorption isotherms; Isothermal Titration Calorimetry

  • Lecture (Conference)
    International Conference on Metal-Binding Peptides: Methodologies and Applications, 05.-08.07.2022, Nancy, Frankreich

Permalink: https://www.hzdr.de/publications/Publ-35888


Identification, characterization and optimization of lanthanide ion binding peptides for the recovery of rare earth elements

Claus, G.; Lederer, F.; Boelens, P.; Drobot, B.

Abstract

Lanthanides are indispensable in times of modern technology and of extremely high relevance for the future due to their special properties. They provide essential components for high tech products and are used in environmental technology and the green tech industry, which focuses on sustainable products. The growing demand for these valuable metals and the existing high supply risk at the same time, as well as climate and environmental protection policies, are increasingly driving the search for alternative lanthanide extraction solutions. Therefore, a central issue is the recycling of lanthanides from end-of-life products as well as wastewater from agriculture, industry, hospitals and mining, for example. However, efficient recovery currently appears difficult to impossible, as their separation is associated with high costs – not least because of their chemically and physically very similar properties and their relatively low concentration in the product material and waste streams. For these reasons, there is intensive research into new recycling processes to enable a cost effective and environmentally friendly separation of these metals from electronic waste and wastewater, as well as conservation of and independence from primary resources.
Biocollectors and biohybrid separation platforms are promising novel recycling approaches, which are developed in our team of the Helmholtz Institute Freiberg for Resource Technology and the Institute for Resource Ecology of the Helmholtz-Zentrum Dresden-Rossendorf. The new approaches are composed of an appropriate carrier material and target specific peptides immobilized on it and are intended to extract the critical metals from electronic scrap, process waste streams or primary raw material mixtures in this way (Figure 1).
Phage surface display technology was applied for the identification and enrichment of those peptides that show an affinity for europium ions. In a competitive binding experiment, the selected peptide motifs were further reduced and non-specific sequences were discarded. The resulting best europium binding peptide variants were characterized by time-resolved laser fluorescence spectroscopy with respect to their affinity for europium ions and, if necessary, are optimized by site-directed mutagenesis. The four EF-hand peptides from the protein calmodulin will serve as a reference system.

Keywords: Phage surface display; biopanning; lanthanides; europium; specific peptides; biohybrid separation; REE recovery

  • Lecture (Conference)
    International Conference on Metal-Binding Peptides: Methodologies and Applications, 05.-08.07.2022, Nancy, Frankreich

Permalink: https://www.hzdr.de/publications/Publ-35887


BioKollekt – A novel peptide-based separation platform for electronic scrap

Lederer, F.; Claus, G.; Matys, S.; Boelens, P.

Abstract

Circular economy, growing electronic waste piles and resource scarcity request for efficient ways for the recycling of electronic scrap. There are numerous recycling strategies known for precious metals. However, the recycling rates for a majority of elements are still low. The main reason for the lack of feasible recycling methods are the low costs for primary resources on the market. Other reasons are the high diversity and mostly low concentrations of valuable elements in electronic devices. Until now, biological recycling tools are not applied for resource recovery even though they could help to solve numerous challenges. Biological tools provide various potential recycling techniques, such as surface binding, mineral dissolving, transformation and metal complexation [1]. Using highly selective biomolecules like peptides delivers material selectivity in a complex mixture. Peptides are biodegradable, can be produced in high amounts chemically or biologically and are more robust compared to larger biomolecules [2].
The BioKollekt group develops a novel, peptide-based separation platform for certain elements that are part of electronic scrap (Fig.1). The peptides were identified using phage surface display (PSD). Target materials for motif identification were particles of the rare earth containing lamp phosphor powders LaPO4:Ce,Tb (LAP) and CeMgAl11O19:Tb (CAT). The peptides RCQYPLCS and ETKKCTTGPCKVVT were identified as selectively binding to LAP and CAT respectively [2, 3]. In the BioKollekt approach, these peptides are used to functionalize carrier materials such as magnetic carriers. Based on these functionalized carrier materials, appropriate e-waste particle separation processes were designed [4]. The major goal of our research is the development of an eco-friendly, efficient and sustainable recycling process for metals in electrical devices. Peptides, as relatively robust biomolecules with a giant variety of possible binding motifs, are the perfect key to interact with target metals. In this biogenic approach, we combine the target metal binding characteristics of the peptides with the separation process-supporting characteristic of the carrier. As a positive side effect, the design of the biocollector addresses its own reusability. That makes the process more sustainable in respect to resources and the positive impact on the ecological footprint of the recycled product, as well as more efficient in respect to costs and effort.

Keywords: circular economy; electronic waste; phage surface display; biocollector; magnetic separation

  • Lecture (Conference)
    International conference on Metal-binding peptides, 05.-08.07.2022, Nancy, Frankreich

Permalink: https://www.hzdr.de/publications/Publ-35886


"Elektroschrott-Recycling mit Viren" im ZDF Leschs Kosmos Beitrag "Der Schatz in der Mülltonne"

Lederer, F.; Boelens, P.; Vogel, M.; Bobeth, C.; Kießlich, T.; Bloß, C.; Wei, T.-S.; Drobot, B.

Abstract

Im Leschs Kosmos Beitrag "Der Schatz in der Mülltonne" wurde der Einsatz von Biokollektoren der Nachwuchsforschergruppe BioKollekt filmisch dokumentiert. Ein Team von Wissenschaftlern des HIF, des IRE und des VKTA zeigten dabei die verschiedenen Schritte vom Phage Surface Display, über die Funktionalisierung von magnetischen Kügelchen bis zur Abtrennung des Lampenpulvers und dessen Nachweis über TRLFS. Arbeitsschritte, welche aufgrund der Größe der Materialien filmisch nicht passend dargestellt werden konnten, wurden durch einen Graphiker im Leschs Kosmos Team animiert.

Keywords: Bakteriophagen; Bioangeln; Lampenpulver; Next Generation Sequencing; Bioinformatik; High Gradient Magnetic Separator; TRLFS

  • Open Access Logo Communication & Media Relations
    Leschs Kosmos Fernsehdokumentationsbeitrag 06.09.2022

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Permalink: https://www.hzdr.de/publications/Publ-35885


Wie Biologie beim Recycling hilft

Lederer, F.

Abstract

Neuste biotechnologische Methoden nutzen Biolaugung, Biosorption und Bioflotation, um die eher klassisch ausgerichteten Industriezweige Bergbau und
Mülltrennung zu ergänzen. In der Abteilung Biotechnologie am Helmholtz Institut Freiberg für Ressourcentechnologie werden durch die Kombination von
Biotechnologie mit verschiedenen klassischen Wissenschaften neue Lösungen für bisher ungelöste Probleme und neue Abfallströme gefunden.

Keywords: Biologie; Recycling; Elektroschrott

  • Lecture (others)
    Tag der Wissenschaft, 29.06.2022, Radebeul, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35884


Radiosynthesis and biological evaluation of [¹ ⁸F]AG-120 as imaging agent for the detection of the mutant isocitrate dehydrogenase 1 in glioma by PET

Toussaint, M.; Lai, T. H.; Dukic-Stefanovic, S.; Teodoro, R.; Moldovan, R.-P.; Meister, S.; Ullrich, M.; Pietzsch, J.; Kopka, K.; Juratli, T. A.; Wenzel, B.; Deuther-Conrad, W.

Abstract

Introduction: Glioma are clinically challenging tumors due to their location and invasiveness, limiting their complete surgical resection. Mutated isocitrate dehydrogenase enzymes (IDH) are frequent alterations - the most common being the IDH1R132H - expressed only in glioma but not in healthy brain, correlating with prognosis. Hence, the evaluation of the IDH mutation status has become essential in clinical patient stratification. Currently, the IDH mutations are determined either directly by invasive biopsies or indirectly by magnetic resonance spectroscopy. Here, we propose a transdisciplinary approach to develop an 18F-labeled ligand to detect the IDH1R132H protein directly and non-invasively by positron emission tomography (PET) imaging. Such an imaging tool could improve the selection of cancer patients who are most likely to benefit from precision medicine. In the present study, we performed the radiofluorination of AG-120 (Ivosidenib), an FDA-approved small molecule inhibitor of mutant-IDH.

Methods: The stannyl precursor (HL174) was synthetized according to the published synthesis of AG-120 [1] with minor modifications. The radiosynthesis was performed by copper-mediated radiofluorination of HL174 (Fig. 1) using a TRACERlab FX2 N synthesis module. The inhibitory potency of AG-120 was measured with a diaphorase/resazurin coupled assay using recombinant IDH1R132H or IDH1 (n=2). Internalization of [18F]AG-120 were determined in vitro using U251 human glioblastoma cells stably transfected with IDH1 or IDH1R132H [2]. In vivo metabolism was investigated in healthy CD-1 mice (n=3) by radio-chromatographic analyses of plasma and brain tissue. Dynamic PET (Mediso, nanoScan® PET/CT) imaging studies were performed in nude rats bearing U251-IDH1 (n=2) or U251-IDH1R132H (n=2) glioblastoma.

Results: For the first time, diastereomerically pure [18F]AG-120 was prepared by an automated copper-mediated radiolabelling approach without azeotropic drying starting from the stannyl precursor HL174 (Fig.1). AG-120 shows a high inhibitory potency toward the IDH1R132H (IC50 IDH1R132H=5.11 nM). Internalization studies revealed a significantly higher uptake (0.422 vs. 0.014% AD/μg protein at 120min) of [18F]AG-120 in U251-IDH1R132H cells in comparison to U251-IDH1 cells, suppressible by self-blocking (0.422 vs. 0.009% AD/μg protein at 120min). [18F]AG-120 is metabolized relatively slow with parent fractions of 85% and 91% in plasma and brain, respectively, at 30min p.i.. Dynamic PET studies show a limited blood-brain barrier (BBB) permeation of [18F]AG-120 along with a low uptake in the brain tumor (TAC peak value ~0.4 SUV at 0.6min), which did not differ significantly between IDH1R132H- and IDH1-tumors (tumor-to-blood ratio[40-60min]: ~1.7 vs. ~1.3).

Conclusions: We successfully established an automated radiosynthesis of [18F]AG-120. The preliminary preclinical evaluation revealed a target-specific internalization in vitro and a high metabolic stability in vivo. Despite a generally low BBB penetration of [18F]AG-120, a slightly higher accumulation of activity in IDH1R132H-glioblastoma in comparison to the IDH1 glioblastoma could be observed. Altogether, these results encourage the evaluation of [18F]AG-120 in models of peripheral cancers such as chondrosarcoma.

Acknowledgements: We thank the European-Regional-Development-Fund and the Sächsische-Aufbaubank for the financial support (project no. 100364142); Dr. Kessler, Prof. Vordermark for the cells and Mrs. Barth for the PET experiments.

References:

[1] Popovici-Muller et al., 2018. ACS Med Chem Lett, 9: 300-305.
[2] Kessler et al., 2015. Radiother Oncol, 116: 381-387.

Keywords: PET imaging; Glioma; IDH1 mutation; AG-120; fluorine-18

  • Poster
    The 25th iSRS, 22.-26.05.2023, Honolulu, USA

Permalink: https://www.hzdr.de/publications/Publ-35883


aflow++: a C++ framework for autonomous materials design

Oses, C.; Esters, M.; Hicks, D.; Divilov, S.; Eckert, H.; Friedrich, R.; Mehl, M. J.; Smolyanyuk, A.; Campilongo, X.; van de Walle, A.; Schroers, J.; Kusne, A. G.; Takeuchi, I.; Zurek, E.; Buongiorno Nardelli, M.; Fornari, M.; Lederer, Y.; Levy, O.; Toher, C.; Curtarolo, S.

Abstract

The realization of novel technological opportunities given by computational and autonomous materials design requires efficient and effective frameworks. For more than two decades, aflow++ (Automatic-Flow Framework for Materials Discovery) has provided an interconnected collection of algorithms and workflows to address this challenge. This article contains an overview of the software and some of its most heavily-used functionalities, including algorithmic details, standards, and examples. Key thrusts are highlighted: the calculation of structural, electronic, thermodynamic, and thermomechanical properties in addition to the modeling of complex materials, such as high-entropy ceramics and bulk metallic glasses. The aflow++ software prioritizes interoperability, minimizing the number of independent parameters and tolerances. It ensures consistency of results across property sets — facilitating machine learning studies. The software also features various validation schemes, offering real-time quality assurance for data generated in a high-throughput fashion. Altogether, these considerations contribute to the development of large and reliable materials databases that can ultimately deliver future materials systems.

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Permalink: https://www.hzdr.de/publications/Publ-35881


aflow.org: a web ecosystem of databases, software and tools

Esters, M.; Oses, C.; Divilov, S.; Eckert, H.; Friedrich, R.; Hicks, D.; Mehl, M. J.; Rose, F.; Smolyanyuk, A.; Calzolari, A.; Campilongo, X.; Toher, C.; Curtarolo, S.

Abstract

To enable materials databases supporting computational and experimental research, it is critical to develop platforms that both facilitate access to the data and provide the tools used to generate/analyze it — all while considering the diversity of users’ experience levels and usage needs. The recently formulated FAIR principles (Findable, Accessible, Interoperable, and Reusable) establish a common framework to aid these efforts. This article describes aflow.org, a web ecosystem developed to provide FAIR-compliant access to the AFLOW databases. Graphical and programmatic retrieval methods are offered, ensuring accessibility for all experience levels and data needs. aflow.org goes beyond data-access by providing applications to important features of the AFLOW software [1], assisting users in their own calculations without the need to install the entire high-throughput framework. Outreach commitments to provide AFLOW tutorials and materials science education to a global and diverse audiences will also be presented.

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Permalink: https://www.hzdr.de/publications/Publ-35880


Data-Driven Research for the Discovery of Novel Two-Dimensional Materials

Friedrich, R.

Abstract

Data-Driven Research for the Discovery of Novel Two-Dimensional Materials

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  • Invited lecture (Conferences)
    DFG CRC 1415 Young Investigator Symposium, 21.11.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35879


Data-Driven Design of Two-Dimensional Non-van der Waals Systems and Ionic Materials

Friedrich, R.

Abstract

Data-Driven Design of Two-Dimensional Non-van der Waals Systems and Ionic Materials

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  • Invited lecture (Conferences)
    Seminar Theoretische Chemie TU Dresden, 19.04.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35878


Data-Driven Design of Two-Dimensional Non-van der Waals Materials and Cation Exchange in CdSe Nanoplatelets

Friedrich, R.; Ghorbani Asl, M.; Curtarolo, S.; Shamraienko, V.; Subakti, S.; Lubk, A.; Eychmüller, A.; Krasheninnikov, A.

Abstract

Data-Driven Design of Two-Dimensional Non-van der Waals Materials and Cation Exchange in CdSe Nanoplatelets

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  • Poster
    Retreat of the DFG CRC1415, 15.06.2022, Lichtenwalde, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35877


State-of-the-art biotechnological recycling processes

Chakankar, M. V.; Lederer, F.; Jain, R.; Matys, S.; Kutschke, S.; Pollmann, K.

Abstract

Electronic waste is very heterogeneous yet attractive secondary source of many base and critical metals. Various bioprocesses are being studied extensively as an environmentally friendly route not only for resource recovery from wastes but also for pollution mitigation. Consequently, application of biotechnological processes for the metal recovery from electronic waste is evolving as the green and sustainable method for resource recovery. This chapter explores various state-of-the-art bioprocesses for recycling electronic wastes including bioleaching, biosorption and bioflotation. The chapter draws attention to the use of microorganisms and various biomolecules in such processes and facilitates the better understanding of fundamental mechanisms. In addition, it provides the future directions for use of novel biotechnologies and interdisciplinary approaches for such recycling processes.

Keywords: Biotechnological approach; Bioleaching; Biosorption; Bioreduction; Bioflotation; Metals; Recovery

  • Book chapter
    Anshu Priya, Subrata Hait: Management of Electronic Waste: Resource Recovery, Technology and Regulation, United States: John Wiley & Sons, 2023, 978-1-119-89433-9
    DOI: 10.1002/9781119894360.ch15

Permalink: https://www.hzdr.de/publications/Publ-35876


Data-Driven Design of Two-Dimensional Non-van der Waals Materials

Friedrich, R.; Ghorbani-Asl, M.; Curtarolo, S.; Krasheninnikov, A. V.

Abstract

Two-dimensional (2D) materials are traditionally associated with the sheets forming bulk layered compounds bonded by weak van der Waals (vdW) forces. The unexpected experimental realization of non-vdW 2D compounds, for which previously developed descriptors are not applicable, opened up a new direction in the research on 2D systems [1]. Here, we present our recent data-driven search for representatives of this novel materials class [2]. By screening the AFLOW database according to structural prototype information, 28 potentially synthesizable candidates are outlined. The oxidation state of the surface cations is found to regulate the exfoliation energy with low oxidation numbers giving rise to weak bonding – thus providing an enabling descriptor to obtain novel 2D materials. The candidates showcase a versatile spectrum of appealing electronic, optical and magnetic properties.

[1] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).

[2] R. Friedrich et al., Nano Lett. 22, 989 (2022).

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  • Poster
    Psi-k Conference, 23.08.2022, Lausanne, Schweiz

Permalink: https://www.hzdr.de/publications/Publ-35875


Bioionflotation: Biotechnical approach for metal recovery from low concentrated waters

Chakankar, M. V.; Pollmann, K.; Rudolph, M.

Abstract

Ion flotation is a well-known process for the separation or removal of metal ions at a low concentra-tion from aqueous solutions. The use of various flotation agents is well documented, yet there is a high demand for new flotation agents. The new ion flotation agents need to be highly selective, effi-cient, and environmentally friendly. Microbial biosurfactants with high surface activity and metal complexation ability are molecules of interest in this regard. The use of these biomolecules as flota-tion reagents in the ion flotation process can be termed as ‘bioionflotation’. This biotechnological approach for metal recovery from low concentrated waters is still dawning and more research is required to improve the selectivity and process efficiency. This study investigated the separation of gallium (Ga) from aqueous solutions using rhamnolipid biosurfactant as the flotation reagent. The systematic study showed the influence of metal ions on surface activity and foaming properties of the biosurfactant. Further effects of various operating parameters on the metal recovery and selec-tivity were studied. The flotation results of the mixed metal solutions (containing Ga and As at 1 mM concentration), showed nearly 60% and 3.5% of Ga and As recovery, respectively, at 0.85 mM rhamnolipid concentration at pH 6 and air flow rate of 40 ml/min. Further, the selectivity index for Ga over As was 17.2 for the studied system. These results provide insights on the parameters influ-encing the properties of flotation collectors and provide the basis for the development of the bioion-flotation process for effective and selective separation of metal ions from low concentrated waters. These results also indicate the role of biosurfactants as a promising green flotation reagent.

Keywords: biosurfactant; flotation reagent; gallium; rhamnolipid; ion flotation

  • Lecture (Conference)
    The 24th International Biohydrometallurgy Symposium 2022, 20.-23.11.2022, Perth, Australia

Permalink: https://www.hzdr.de/publications/Publ-35874


Data-Driven Design of Two-Dimensional Non-van der Waals Materials

Friedrich, R.; Ghorbani-Asl, M.; Curtarolo, S.; Krasheninnikov, A. V.

Abstract

Two-dimensional (2D) materials are traditionally associated with the
sheets forming bulk layered compounds bonded by weak van der Waals
(vdW) forces. The weak inter-layer interaction leads to a natural structural
separation of the 2D subunits in the crystals, giving rise to the
possibility of mechanical and liquid-phase exfoliation as well as enabling
the formulation of exfoliability descriptors.
The unexpected experimental realization of non-vdW 2D compounds,
for which the previously formulated descriptors are not
applicable, opened up a new direction in the research on 2D systems
[1]. Here, we present our recent data-driven search for representatives
of this novel materials class [2]. By screening the AFLOW database
according to structural prototypes, 28 potentially synthesizable candidates
are outlined. The oxidation state of the surface cations is
found to regulate the exfoliation energy with low oxidation numbers
giving rise to weak bonding — thus providing an enabling descriptor
to obtain novel 2D materials. The candidates showcase a diverse
spectrum of appealing electronic, optical and magnetic features.
[1] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).
[2] R. Friedrich et al., Nano Lett. 22, 989 (2022).

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  • Lecture (Conference)
    DPG Frühjahrestagung, 08.09.2022, Regensburg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35873


Automated Enthalpy Corrections for Materials Design of Ionic Systems: AFLOW-CCE

Friedrich, R.; Esters, M.; Oses, C.; Ki, S.; Brenner, M. J.; Hicks, D.; Mehl, M. J.; Toher, C.; Curtarolo, S.

Abstract

Materials databases such as AFLOW [1] leverage ab initio calculations
for autonomous materials design. The predictive power critically relies
on accurate formation enthalpies — quantifying the thermodynamic
stability of a system. For ionic materials such as oxides and nitrides,
standard DFT leads to errors of several hundred meV/atom [2,3].
We have recently developed the "coordination corrected enthalpies"
(CCE) method yielding highly accurate room temperature formation
enthalpies with mean absolute errors down to 27 meV/atom [3]. Here,
we introduce AFLOW-CCE [4] — our implementation of CCE into
the AFLOW framework. It provides a tool where users can input
a structure file and receive the CCE corrections, or even the CCE
formation enthalpies if pre-calculated LDA, PBE or SCAN values are
provided. The implementation features a command line tool, a web
interface, and a Python environment.
[1] S. Curtarolo et al., Comput. Mater. Sci. 58, 218 (2012).
[2] V. Stevanović et al., Phys. Rev. B 85, 115104 (2012).
[3] R. Friedrich et al., npj Comput. Mater. 5, 59 (2019).
[4] R. Friedrich et al., Phys. Rev. Mater. 5, 043803 (2021).

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  • Lecture (Conference)
    DPG Frühjahrestagung, 06.09.2022, Regensburg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35872


Data-Driven Design of Two-Dimensional Non-van der Waals Materials

Friedrich, R.

Abstract

Two-dimensional (2D) materials are traditionally associated with the sheets forming
bulk layered compounds bonded by weak van der Waals (vdW) forces with graphene
derived from bulk graphite being the most prominent example. The weak inter-layer
interaction leads to a natural structural separation of the 2D subunits in the crystals,
giving rise to the possibility of mechanical and liquid-phase exfoliation. The anisotropic
interaction also provided suitable structural criteria for the computational search for
such traditional 2D materials which predicted about 2000 exfoliable compounds [1].
However, the unexpected experimental realization of atomically thin sheets from
non-vdW bonded compounds, for which the previously formulated descriptors are
not applicable, recently opened up a new direction in the research on 2D materials
[2]. These non-vdW 2D compounds exhibit qualitatively new features due to the
unsaturated bonds at their surfaces. Here, we present our recent data-driven search
for representatives of this novel materials class [3]. By screening the AFLOW
database according to structural prototype information 28 new, potentially
synthesizable candidates are outlined. The oxidation state of the surface cations is
found to regulate the exfoliation energy with low oxidation numbers giving rise to
weak bonding – thus providing an enabling descriptor to obtain novel 2D materials.
The candidates showcase a versatile spectrum of appealing electronic, optical and
magnetic properties suggesting in particular spintronic applications.
[1] N. Mounet et al., Nat. Nanotechnol. 13, 246 (2018).
[2] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).
[3] R. Friedrich et al. Nano Lett. 22, 989 (2022).

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  • Invited lecture (Conferences)
    CECAM Workshop Virtual Materials Design, 18.07.2022, Karlsruhe, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35871


Data-Driven Design of Two-Dimensional Non-van der Waals Materials

Friedrich, R.

Abstract

Two-dimensional (2D) materials are traditionally associated with the sheets forming bulk layered
compounds bonded by weak van der Waals (vdW) forces with graphene derived from bulk
graphite being the most prominent example. The weak inter-layer interaction leads to a natural
structural separation of the 2D subunits in the crystals, giving rise to the possibility of mechanical
and liquid-phase exfoliation. The anisotropic interaction also provided suitable structural criteria
for the computational search for such traditional 2D materials which predicted about 2000
exfoliable compounds [1].
However, the unexpected experimental realization of atomically thin sheets from non-vdW
bonded compounds, for which the previously formulated descriptors are not applicable, recently
opened up a new direction in the research on 2D materials [2]. These non-vdW 2D compounds
exhibit qualitatively new features due to the unsaturated bonds at their surfaces. Here, we present
our recent data-driven search for representatives of this novel materials class [3]. By screening
the AFLOW database according to structural prototype information 28 new, potentially
synthesizable candidates are outlined. The oxidation state of the surface cations is found to
regulate the exfoliation energy with low oxidation numbers giving rise to weak bonding – thus
providing an enabling descriptor to obtain novel 2D materials. The candidates showcase a
versatile spectrum of appealing electronic, optical and magnetic properties suggesting in
particular spintronic applications.
[1] N. Mounet et al., Nat. Nanotechnol. 13, 246 (2018).
[2] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).
[3] R. Friedrich et al., Nano Lett. 22, 989 (2022).
Acknowledgements:
The authors thank the HZDR Computing Center, HLRS, Stuttgart, Germany, and TU Dresden
Cluster “Taurus” for generous grants of CPU time. R.F. acknowledges support from the
Alexander von Humboldt foundation under the Feodor Lynen research fellowship. A.V.K. thanks
the German Research Foundation (DFG) for the support through Project KR 4866/2-1 and the
collaborative research center “Chemistry of Synthetic 2D Materials” SFB-1415-417590517.

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  • Invited lecture (Conferences)
    CASUSCON, 13.07.2022, Breslau, Polen

Permalink: https://www.hzdr.de/publications/Publ-35870


Assessing fundamental parameters of magnetic properties of actinide containing samples

Fichter, S.; Gericke, R.; Duckworth, T.; Hong, B.; März, J.; Patzschke, M.; Schmidt, M.; Stumpf, T.; Kaden, P.

Abstract

A study of acinide amidinate complexes is presented with an emphasis on magnetic properties. Main method is paramagnetic NMR spectroscopy highlighting pseudo-contact shifts and minor Fermi contact contributions to the observed NMR chemical shifts. As an outlook EPR spectroscopy and upcoming SQUID magnetometry is advertised.

Keywords: actinides; magnetic properties; NMR; EPR; SQUID; PCS; FCS; amidinate

  • Poster
    Actinides revisited 2022, 21.-23.09.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35869


Resource recovery: Innovative approaches with biomolecules

Lederer, F.

Abstract

The Biotechnology Division at HIF uses diverse biomolecules for their application in resource recovery. This talk gives an overview on running projects and available biomolecules.

Keywords: peptides; organic acids; biotensides; siderophores

  • Invited lecture (Conferences) (Online presentation)
    Biokolloquium, 26.04.2022, Jena, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35868


Functionalization and radiolabeling of M13 bacteriophages for PET imaging

Trommer, J.; Volesak Francova, P.; Kučka, J.; Emidio Costantini, P.; Castagnola, V.; Danielli, A.; Calvaresi, M.; Šefc, L.; Benfenati, F.; Kopka, K.; Zarschler, K.

Abstract

Objectives and Introduction
Parkinson’s disease is caused by degeneration of nigro-striatal dopaminergic neurons and denervation of the target neurons in the neostriatum. The resulting disruption of dopaminergic modulation produces an imbalance between antagonistic pathways in the basal ganglia leading to rigidity, tremor, and bradykinesia [1]. One of several treatment options is the so called deep-brain-stimulation (DBS), whereby an electrode is implanted to re-equilibrate the nervous pathways and rescue the pathological imbalance. Though highly effective, DBS is linked to a very complex surgical procedure and can lead to adverse neurological effects [2,3].
The goal of this project is to enable a selective stimulation of striatal dopaminoceptive neurons from outside the brain through polymeric photovoltaic nanoparticles which are transported to the neostriatum using an engineered M13 bacteriophage as nanocarrier. These phages were chosen as a biovector since their filamentous envelop, formed by the major coat protein P8, offers a large surface area which can be modified easily. To monitor its biodistribution in the organism, the engineered bacteriophage is being with [64Cu]CuCl2 enabling PET imaging.

Methods:

Methods for analysis of the phages by TLC, HPLC and MALDI-TOF MS have been developed. To allow labeling with 64Cu, the bacteriophages were functionalized with 1,4,7‑triazacyclononane,1‑glutaric acid‑4,7-acetic acid (NODA-GA) and the conjugation reaction was analyzed by MALDI-TOF MS. The M13-NODA-GA conjugates were purified using HPLC-SEC. After labeling of the M13-NODA-GA conjugates with inhouse produced [64Cu]CuCl2 and purification by spin filtration, the radiolabeling efficiency was analyzed by radio-TLC and radio-HPLC-SEC. PET imaging was carried out in mice and scans were taken every 15 min up to 1 h after intravenous injection. The mice were sacrificed 70 min post-injection and the radioactivity accumulated in different organs was measured.

Results:

Conjugation of the NODA-GA chelator to the major capsid protein P8 of the phages was confirmed by MALDI-TOF MS. Subsequent radiolabeling of the bioconjugates was achieved with a specific activity of 17 MBq/pmol and a radiochemical purity of 98.5% was obtained as determined by radio-TLC as well as radio-HPLC-SEC. A rapid accumulation of the radiolabeled M13-NODA-GA conjugates in the murine liver was observed by PET imaging 15 min post-injection. According to ex vivo analysis, approximately 80% of the injected dose was accumulated in the liver, and smaller amounts were detected in spleen (~ 5%) and in the gastrointestinal tract (<1%).

Conclusions:

The present study shows for the first time the successful chemical modification and 64Cu-labeling of NODA-GA-functionalized M13 bacteriophages as well as their biodistribution. Furthermore, a set of analytical methods is presented allowing the assessment of bacteriophage purity, integrity as well as stability in future studies.

Acknowledgements:

The research work was financially supported by the EU Joint Programme – Neurodegenerative Disease Research (NeuroPhage, Project ID: JPND2020-568-126). The financial support (Project ID: 01ED2108) by the German Federal Ministry of Education and Research (BMBF) is gratefully acknowledged.

References:

[1] Balestrino R and Schapira A H V, Eur. J. Neurol. 2020; 27: 27–42.
[2] Stoker T B et al., Front. Neurosci. 2018; 12:693.
[3] Krack P et al., Mov. Disord., 2019; 34: 12

Keywords: Bacteriophage; M13; Copper-64; Radiolabeling; Parkinson's disease

  • Lecture (Conference)
    25th International Symposium on Radiopharmaceutical Chemistry, 22.-26.05.2023, Honolulu, Hawaii, USA

Permalink: https://www.hzdr.de/publications/Publ-35867


Dynamic Gas Injection

Herrmann-Heber, R.; Reinecke, S.; Meier, M.; Hampel, U.

Abstract

The previous investigations showed that the pulsed aeration leads to higher oxygen mass transfer rates in specific cases. In narrow aeration columns positive effects could be shown for higher pulsation frequencies whereas in the DN900 column these effects were only pre-sent for higher flow rates in low frequencies. Investigations of bubble size distributions showed that the bubble size is not the only factor leading to increased oxygen mass transfer rates and that the positive effects depend on the geometry and the liquid flow behavior in the reactor. Further experiments therefore are focused on fundamental investigation the liquid flow behavior during pulsed aeration. A new experimental setup was constructed to study these hydrodynamic effects in 2D to enable a better understand of the underlying effects.

Keywords: Dynamic aeration; wastewater treatment; gas injection; pulsation

Involved research facilities

  • TOPFLOW Facility
  • Article, self-published (no contribution to HZDR-Annual report)
    Forschungszentrum Rossendorf 2022
    40 Seiten
    ISSN: 2191-8708, eISSN: 2191-8716

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Permalink: https://www.hzdr.de/publications/Publ-35866


Choosing the right molar activity of an 123I-labeled irreversible inhibitor of transglutaminase 2 for quantitative expression profiling in tissues

Donat, C.; Laube, M.; Kopka, K.; Pietzsch, H.-J.; Pietzsch, J.; Löser, R.; Wodtke, R.

Abstract

Objectives:

The Ca2+-dependent transamidase activity of transglutaminase 2 (TGase2) is tightly regulated in healthy cells but can be utilized by various cancer cells to support their survival and progression. Therefore, molecules targeting this enzyme are promising candidates for the functional characterization of TGase2 in tumors. Recently, we developed an 18F-labeled irreversible inhibitor and highlighted its potential as radiometric tool for the in vitro characterization of TGase2. Herein, we report on the kinetic characterization of a 123I-labeled Nε-acryloyllysine, [123I]1, and its use for quantifying the functional expression of TGase2 in tissues
Methods:
[123I]1 was synthesized as recently presented [1]. The inhibitory potency of [123I]1 by means of its kinact/KI value was determined by a radio-TLC method using recombinant human TGase2. In vitro autoradiography was performed with fresh-frozen sections (12 µm) of several organs (heart, kidney, liver, spleen, and muscle), extracted from healthy NMRI nude mice. Binding experiments with [123I]1 were conducted at 0.7 MBq/mL in MOPS buffer at pH 7.4 containing 3 mM CaCl2 and 5 mM DTT. Non-specific binding was assessed in the presence of the TGase2 inhibitor Z006. Different molar activities (Am) were adjusted by the addition of compound 1.
Results:
[123I]1 was reliably obtained in high (radio)chemical purities of >99% and radiochemical yields of 79±6% (n=8). The Am was determined to be >6 TBq/µmol and the kinact/KI value to be 10,200 M-1s-1 (±1,000). Association (Figure 1) of n.c.a. [123I]1 at 37°C over 4 h to tissue sections furnished a high binding capacity and excellent ratios of total binding (TB) to non-specific binding (NSB). However, assessment of the quantitative TGase2 expression is limited as the inhibition rate at n.c.a. level is too low to achieve complete radioligand binding. Therefore, Am values of 70, 14, 7, and 1 GBq/µmol were adjusted to increase the association rates. A value of 7 GBq/µmol appeared to be optimal based on the extent of binding and the TB/NSB ratios. Higher Am values of 70 and 14 GBq/µmol still led to incomplete reaction and thus a lower apparent TGase2 concentration. In contrast, a Am value of 1 GBq/µmol resulted in extensive self-block, as indicated by an increased NSB (Figure 1). The highest TGase2 concentration has been observed in the heart and was lowest in muscle, with values of 1.3 and 0.2 pmol/mm3, respectively. Dissociation of [123I]1 under similar conditions proved the irreversible binding to TGase2 as only a minimal amount (<10%) of total bound radioligand dissociates over 4 h.
Conclusions:
A detailed in vitro and ex vivo evaluation of the TGase2-inhibitor [123I]1 proved its applicability as radiometric tool for quantifying the functional expression of that enzyme. The observed low reaction rate of [123I]1 at high Am values was compensated by standard addition which might also have implications for the in vivo application of this compound.
Acknowledgements:
The authors thank ROTOP Radiopharmacy for continuously providing [123I]iodide. Financial support by European Regional Development Fund (EFRE) for ML, HJP and RW is gratefully acknowledged.
References:
[1] Laube et al, Nucl. Med. Biol., 2021, 96–97S, S79-S80,

Involved research facilities

  • PET-Center
  • Poster
    International Symposium of Radiopharmaceutical Sciences, 29.05.-02.06.2022, Nantes, Frankreich

Permalink: https://www.hzdr.de/publications/Publ-35865


The Impact of Nε-Acryloyllysine Piperazides on the Conformational Dynamics of Transglutaminase 2

Heerwig, A.; Kick, A.; Sommerfeld, P.; Eimermacher, S.; Hartung, F.; Laube, M.; Fischer, D.; Pietzsch, H.-J.; Pietzsch, J.; Löser, R.; Mertig, M.; Pietsch, M.; Wodtke, R.

Abstract

In addition to classic functions of proteins such as acting as biocatalyst or binding partner, the conformational states of proteins and their remodeling upon stimulation needs to be considered. A prominent example that undergoes comprehensive conformational remodeling, is transglutaminase 2 (TGase 2), whose distinct conformational states are closely related to particular functions. Its involvement in various pathophysiological processes, including fibrosis and cancer, motivates the development of theranostic agents, particularly based on inhibitors that are directed towards the transamidase activity. In this context, the ability of such inhibitors to control the conformational dynamics of TGase 2 emerges as an important parameter, and methods to assess this property are in great demand. Herein, we describe the application of the switchSENSE® principle to detect conformational changes caused by three irreversibly binding Nε-acryloyllysine piperazides, which are suitable radiotracers candidates of TGase 2. The switchSENSE® technique is based on DNA levers actuated by alternating electric fields. These levers are immobilized on gold electrodes with one end, and at the other, distal end of the lever, the TGase 2 is covalently bound. A novel computational method is introduced for describing the resulting lever motion to quantify the extent of stimulated conformational TGase 2 changes. Moreover, as a complementary biophysical method, native polyacrylamide gel electrophoresis was performed under similar conditions to validate the results. Both methods prove the occurrence of an irreversible shift in the conformational equilibrium of TGase 2, caused by the binding of the three studied Nε-acryloyllysine piperazides.

Keywords: transamidase inhibitor; DNA nanolever; binding kinetics; conformational change

Involved research facilities

  • ZRT

Permalink: https://www.hzdr.de/publications/Publ-35864


Strategies to Reduce Kidney Uptake of Radiolabeled Biomolecules

Wodtke, R.

Abstract

Peptide receptor radionuclide therapy (PRRT) or radioligand therapy (RLT) represent valuable nuclear medical approaches for the treatment of tumors. It can lead to an unparalleled therapeutic success with [177Lu]Lu-DOTA-TATE1 and [177Lu]Lu-PSMA-6172 being the most striking examples, which were recently approved as Lutathera and Pluvicto, respectively. Besides stimulating the search for further targeted radiopharmaceuticals,3 there are ongoing efforts for optimizing PRRT and RLT apart from the tumor targeting itself. A non-negligible aspect for PRRT and RLT is radiation induced toxicity to healthy tissue, in particular bone marrow and kidneys but also other organs such as salivary glands in case of RLT with [177Lu]Lu-PSMA-617,4,5,6 that also limits the height of the applied activity amount. Due to the high hydrophilicity of somatostatin and PSMA ligands, their primary route of excretion proceeds via the kidney into the urine. This can be accompanied by a significant receptor-mediated reabsorption of the radiopharmaceuticals into the proximal tubular cells followed by lysosomal degradation, which ultimately result in a prolonged retention of the radiolabel and thus, a high dose exposure to the kidneys.7,8 Several nephroprotective strategies are pursued to reduce the tubular reabsorption during PRRT or RLT either by modifying the radiopharmaceutical itself or by co-injection of blocking substances.4,7 The talk will give an overview about the different strategies for reducing the renal uptake with a special emphasis on the targeting of renal brush border enzymes by the introduction of cleavable peptide linkers into targeted radiopharmaceuticals.

References:

1. Strosberg et al. Phase 3 trial of 177Lu-Dotatate for midgut neuroendocrine tumors. N. Engl. J. Med. 2017, 376, 125-135.
2. Sartor et al. Lutetium-177-PSMA-617 for metastatic castration-resistant prostate cancer. N. Engl. J. Med. 2021, 385, 1091-1103.
3. Nicolas et al. New Developments in peptide receptor radionuclide therapy. J. Nucl. Med. 2019, 60, 167-171.
4. Geenen et al. Overcoming nephrotoxicity in peptide receptor radionuclide therapy using [177Lu]Lu-DOTA-TATE for the treatment of neuroendocrine tumours. Nucl. Med. Biol. 2021, 102-103, 1-11.
5. Gallyamov et al. Renal outcomes of radioligand therapy: experience of 177lutetium-prostate-specific membrane antigen therapy in metastatic castrate-resistant prostate cancer. 2020, 13, 1049-1055.
6. Kratochwil et al. EANM procedure guidelines for radionuclide therapy with 177Lu-labelled PSMA ligands (177-PSMA-RLT). 2019, 46, 2536-2544.
7. Vegt et al. Renal toxicity of radiolabeled peptides and antibody fragments: Mechanisms, impact on radionuclide therapy, and strategies for prevention. J. Nucl. Med. 2010, 51, 1049-1058.
8. Vegt et al. Renal uptake of different radiolabelled peptides is mediated by megalin: SPECT and biodistribution studies in megalin-deficient mice. Eur. J. Nucl. Med. Mol. Imaging 2011, 38, 623-632.

  • Invited lecture (Conferences)
    35th Annual Congress of the European Association of Nuclear Medicine (EANM), 15.-19.10.2022, Barcelona, Spanien

Permalink: https://www.hzdr.de/publications/Publ-35863


Implications of albumin binding for targeted radiopharmaceuticals

Wodtke, R.

Abstract

Besides optimizing the vector molecule for its interaction toward the respective target protein, a modern tool in the field of radiopharmaceutical cancer therapy is the introduction of albumin-binding moieties to modulate the pharmacokinetic properties [1]. Basically, the approach aims at increasing the time-integral uptake of radioactivity in the tumor, which consequently increases the total radiation dose delivered to the tumor and thus, might improve the therapeutic outcome. In contrast, binding to albumin goes along with a prolonged blood circulation time and thus, a higher radiation dose to healthy tissues, in particular the red bone marrow. Vector molecules of various targets, including folate receptor, prostate specific membrane antigen (PSMA), and fibroblast activation protein (FAP), were equipped with albumin-binding moieties and promising preclinical studies were reported. However, the actual implications of binding to albumin appear less or even erroneously understood. In this context, the protracted tumor uptake is an important aspect, which originates from lowering the unbound fraction of the radioligand in the blood. Moreover, considering the free drug hypothesis [2], the usually observed gain in tumor uptake requires another tumor uptake mechanism of the albumin-bound radioligand to be operational and is not a result of the prolonged blood circulation time.
Based on our own data to albumin-binding radioligands of the somatostatin receptor subtype 2 (SST2) [3], the talk will give insight into the pharmacokinetic implications of albumin binding with a special focus on the relation of the binding affinity to albumin and the resulting biodistribution of the radioligand, which is also of importance for the radiation-induced toxicity to healthy tissues.

References:

1. Brandt M et al.: Nucl. Med. Biol. 2019, 70: 46–52.
2. Smith D A, Di L, Kerns E H: Nat. Rev. Drug Discov. 2010, 9(12): 929–939.
3. Brandt F et al.: J. Med. Chem. 2022, 65(1): 710–733.

  • Invited lecture (Conferences)
    DPhG Annual Meeting 2022 ∙ “From Behring to Biotechnology – moving Pharmaceutical Sciences towards One Health”, 13.-16.09.2022, Marbug, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-35862


Particle yield calculations for different target designs at Mu2e-II

Müller, S.

Abstract

This publication contains configuration files for simulations using the FLUKA2021 radiation transport package for mu- and pi- yields for different production target designs for a possible Mu2e-II experiment at FNAL, US.

Keywords: FLUKA; MU2E-II

Related publications

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Permalink: https://www.hzdr.de/publications/Publ-35861


Experimentos em campos magnéticos pulsados: uma ferramenta poderosa para estudar materiais multicalóricos

Salazar Mejia, C.

Abstract

As instalações de campo pulsado são conhecidas pelos altos campos magnéticos que podem produzir (até 100 Tesla). Por outro lado, para aplicações em refrigeração magnética, os campos magnéticos de até 2 T entram em questão. Portanto, a realização de experimentos com campos magnéticos pulsados para estudar materiais multicalóricos parece ser, pelo menos à primeira vista, supérfluo. No Dresden High Magnetic Field Laboratory, desenvolvemos a técnica para medir diretamente a variação de temperatura da amostra sob campos aplicados que podem ir além de 50 T. A curta duração do pulso (normalmente entre 10 a alguns 100 ms) proporciona boas condições adiabáticas durante o experimento permitindo a medição direta da variação adiabática de temperatura de um material, ΔTad, sem qualquer perda de calor. Além de medir o ΔTad de nossas amostras, mostramos que os campos magnéticos pulsados são uma ferramenta poderosa para estudar e caracterizar materiais multicalóricos. O regime de campos altos permite determinar, por exemplo, o valor de saturação do efeito magnetocalórico e sua máxima extensão em temperature ou podemos induzir a transição do material em uma ampla faixa de temperatura. Efeitos irreversíveis devido à histerese, dinâmica de transição ou a dependência do protocolo de medição do efeito magnetocalórico são geralmente estudados em detalhes em nossas medições. Além disso, a possibilidade de combinar diferentes técnicas e medir simultaneamente a magnetostricção, magnetização e variações de temperatura de uma amostra dá uma visão completa das propriedades do material. Em minha palestra, apresentarei a técnica para determinar diretament o efeito magnetocalórico em campos magnéticos pulsados e mostrarei alguns exemplos de ligas de Heusler.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences) (Online presentation)
    Workshop Brasileiro em Efeitos i-Calóricos, 30.-31.03.2022, online, Brazilia

Permalink: https://www.hzdr.de/publications/Publ-35860


The Use of Magnetic Shape Memory Alloys in Multicaloric Refrigeration Cycles

Gottschall, T.

Abstract

Symposium FM
State-of-the-art Research and Applications of Shape Memory Alloys

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences)
    Cimtec Congress 2022 - 9th Forum on New Materials, 25.-29.06.2022, Perugia, Italien

Permalink: https://www.hzdr.de/publications/Publ-35859


Magnetocaloric materials in high fields: room temperature towards cryogenic applications

Gottschall, T.

Abstract

Virtual conference contribution by invitation

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences) (Online presentation)
    IMRC 2022 - International Materials Research Congress, 17.08.2022, Cancun, Mexico

Permalink: https://www.hzdr.de/publications/Publ-35858


Study on multicaloric Heusler alloys in pulsed magnetic fields

Gottschall, T.

Abstract

No short version available

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences)
    Calorics 2022, 12.-14.09.2022, Cambridge, United Kingdom

Permalink: https://www.hzdr.de/publications/Publ-35857


Magnetische Kühlung: Von Raumtemperatur- hin zu kryogenen Anwendungen

Gottschall, T.

Abstract

Zu diesem eingeladenen Vortrag auf der Calorics 2022 (Kälte-Klima-Tag 2022) in Wien
lag keine Kurzfassung vor.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences)
    Kälte-Klima-Tag 2022, 06.10.2022, Wien, Österreich

Permalink: https://www.hzdr.de/publications/Publ-35856


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