Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

"Online First" included
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Only approved publications

35258 Publications

Effect of temperature and strain rate on the deformation behavior of Ti5321 during hot-compression

Gu, B.; Chekhonin, P.; Xin, S. W.; Liu, G. Q.; Ma, C. L.; Zhou, L.; Skrotzki, W.

The effect of deformation temperature and strain rate (collectively described by the Zener-Hollomon parameter Z) on the deformation mechanism and texture formation of the metastable β-titanium alloy Ti5321 across the β-transus temperature during hot-compression was investigated by electron backscatter diffraction. In the β-phase field, it is found that the deformation behavior and texture formation varies depending on Z. With decreasing Z dynamic recovery and dynamic recrystallization become more and more important. The activation energy for steady state deformation is 240 kJ/mol and 370 kJ/mol in the β- and (α + β)-phase field, respectively. The texture developed is a <100> <111> double-fiber with < 100 > dominating at all deformation conditions. The <111> fiber gets more prominent with increasing Z suggesting that it is mainly related to deformation. Flow softening behavior of Ti5321 is associated with dynamic globularization of the α-phase and promotion of β-grain formation by continuous dynamic recrystallization.

Keywords: Metastable β-titanium alloy; EBSD; Microstructure; Texture; Dynamic recrystallization; Deformation mechanism

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  • Secondary publication expected from 16.04.2022

Permalink: https://www.hzdr.de/publications/Publ-32620
Publ.-Id: 32620


Advanced Git Usage

Erxleben, F.

A talk and demo session on various topics of advanced usage regarding the version control system Git.

Keywords: Git; Talk

  • Open Access Logo Lecture (others) (Online presentation)
    PCD Data Science Basics, 11.05.2021, Hamburg, Deutschland

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32613
Publ.-Id: 32613


Stratigraphy, depositional setting, and shrimp u-pb geochronology of the banded iron formation–bearing bailadila group in the bacheli iron ore mining district, bastar craton, india

Mukhopadhyay, J.; Armstrong, R. A.; Gutzmer, J.; de Kock, M.; Beukes, N. J.

The Bailadila Group of the Bastar Craton, India, is host to a 200-m-thick banded iron formation (BIF). We document the lithostratigraphic context for the BIF, informally referred to as the Bose iron formation, and provide radiometric constraints for its depositional age. Field evidence illustrates that the BIF was deposited on an inner-shelf succession with a quartz arenite that grades upward into the BIF through storm-dominated offshore shelf deposits. The quartz arenite to BIF transition records a relative sea level rise from transgressive to highstand systems tract when the BIFs were deposited in a starved outer continental shelf. U-Pb SHRIMP analyses of zircons from the basement of the Bailadila Group yielded mostly highly discordant U-Pb SHRIMP ages. However, the ages fall on well-defined discordia lines from which concordia intercept ages could be determined. These ages, in combination with the ages of a few zircons that are less than 6% discordant, indicate that the granitoid basement crystallized at 3500–3550 Ma. The maximum depositional age of the Bailadila Group is constrained from the weighted mean207 Pb/206 Pb SHRIMP age of 2725 5 57 Ma from detrital zircons from the basal arenites. A well-constrained weighted mean207 Pb/206 Pb SHRIMP age of 2733 5 53 Ma for zircons from a unit that unconformably overlies the Bailadila Group is within error of that age. Stratigraphic relationships suggest that the Bailadila succession is unconformably overlain by the ~2.5 Ga Kotri and Dongargarh Supergroups. The depositional age of the Bailadila Group is well constrained between ~2.7 and 2.5 Ga. In contrast to most other Archean Algoma-type iron formations of peninsular India, which are closely related to volcanic rocks in greenstone belts, the Bose iron formation is associated with siliciclastic shelf succession. It thus is considered a Superior-type iron formation that represents the oldest known one of its kind in India.

Keywords: banded iron formation; Bastar Cartoon; stratigraphy; age

Permalink: https://www.hzdr.de/publications/Publ-32611
Publ.-Id: 32611


Towards standalone attitude estimation for instrumented flow followers

Buntkiel, L.; Reinecke, S.; Hampel, U.

A concept for 3D-motion tracking of instrumented flow-following sensor particles, equipped with a gyroscope, accelerometer, magnetometer and pressure sensor, has been developed. Consisting of an error state Kalman filter (ESKF) the algorithm can track the attitude of the sensor particle in relation to a reference coordinate system. In this short paper we investigated if the estimated attitude returns to the reference trajectory after experiencing motion similar to a motion that is expected to be found in the multidisperse fluid flows of a biogas fermenter or a waste water treatment basin. Results show the feasibility of the proposed method. However, the strategy of the measurement update in the ESKF needs improvement.

Keywords: error state kalman filter; motion tracking; fluid dynamics; sensor particle; soft sensor

  • Open Access Logo Contribution to proceedings
    Sensor and Measurement Science International 2021, 03.-06.05.2021, Online, Deutschland
    SMSI 2021 - Sensors and Instrumentation, Wunstorf: AMA Service GmbH, 978-3-9819376-4-0, 141-142
    DOI: 10.5162/SMSI2021/B6.3

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32610
Publ.-Id: 32610


Sustainable Development Goal Conflicts in Re-Mining activities

Büttner, P.; Gutzmer, J.; Engelhardt, J.; Martin, M.

The Davidschacht tailings storage facility (TSF), operated from 1944 to 1964, represents one of the largest tailings dams in the historic Freiberg mining district. It contains a volume of 760,000 m³ of sulfidic flotation tailings, residues of former base metal and silver ore beneficiation. The tailings material still contains elevated concentrations of valuable elements such as zinc (0.4 wt.% on average), lead (0.2 wt.%) and copper (0.05 wt.%) as well as indium (10 ppm). The material has thus become the focus of efforts to enable eventual re-mining and recovery of valuable metals. However, such efforts have to take into account a number of important interests of the public. The first of these is the fact that the unrehabilitated tailings pose a significant risk to the environment. Cd (44 ppm on average) and As (0.6 wt.%) concentrations are particularly high – and have a marked influence on the adjacent water bodies, such as the Freiberg Mulde river. Curbing this influence has been the subject of multiple remediation studies, but pressure to act has risen recently due to increasing regulatory demands on the quality of surface water (EU Water Framework Directive of 2000). This is, in principle, very much in favour of re-mining the tailings in an effort to remove also hazardous components. Counteracting this reclamation scenario is the fact that the TSF is part of the UNESCO World Heritage Site “Erzgebirge / Krusne Hory” that was awarded in 2019. Another restriction pertains to the highly protected status of individual species (esp. sand lizard) settling on the TSF surface. This constellation obviously provides ample space for discussion as to how to deal with the tailings material contained in the Davidschacht TSF in future. Different sustainable development goals (SDG) have to be weighed against each other in order to find a holistic and sustainable. Airlift reactor-based bioleaching has been considered as an opportunity to maximize the sustainability of re-mining activities on the Davidschacht TSF. This innovative approach – and its circumstantial limitations – are documented in this contribution.

Keywords: Re-Mining; recomine; Tailing; Davidschacht; HIF; Resource Technology; Freiberg; Sustainable Development Goals; SDG; Bioleaching

Permalink: https://www.hzdr.de/publications/Publ-32609
Publ.-Id: 32609


Diffusion of In Atoms in SiO2 Films Implanted with As+ Ions

Tyschenko, I. E.; Voelskow, M.; Si, Z.; Popov, V. P.

The diffusion of indium atoms in silicon-dioxide films previously implanted with arsenic ions with different energies is studied in relation to the temperature of postimplantation annealing. It is established that the diffusion properties of indium depend on the presence of arsenic atoms in the film and their energy. An increase in the As content in the region of the average projective range of In+ ions prevents the diffusion of In towards the SiO2 film surface at high annealing temperatures and stimulates the diffusion of In deep into the film in the form of a monovalent interstitial site. The experimentally observed effects are interpreted on the assumption of the formation of In–As pairs in neighboring substitutional positions in the SiO2 matrix.

Permalink: https://www.hzdr.de/publications/Publ-32605
Publ.-Id: 32605


Software: Method for real-time controlled tissue theranostics using a single adaptable laser source

Podlipec, R.

Software support for real-time quantification of the treatment effect on the targeted tissue induced by a pulsed laser. Model functions used to quantify laser treatment effect are based on the calculated descriptor values from FLIM (Fluorescence lifetime imaging microscopy) and AF (autofluorescence) diagnostics images done on human retinal tissue using SPC Image software (B&H).

  • Software in the HZDR data repository RODARE
    Publication date: 2021-05-03
    DOI: 10.14278/rodare.971
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32601
Publ.-Id: 32601


ExPaNDS periodic progress report, September 2019 to February 2021

Servan, S.; Konrad, U.

This document presents the progress of the ExPaNDS (European Open Science Cloud Photon and Neutron Services) project after i ts first 18 months of activities, spanning from September 2019 to February 2021. It reproduces the explanation of the work carried out by the ExPaNDS partners as provided to the European Commission in the first periodic report of the project.

Keywords: EOSC; European Open Science Cloud; Photon Science; Neutron Science; Big Data; Information Technology; Forschungsdaten; Reasearch Data

Permalink: https://www.hzdr.de/publications/Publ-32600
Publ.-Id: 32600


Dataset: Method for real-time controlled tissue theranostics using a single adaptable laser source

Podlipec, R.

Raw data of theranostics laser parameters and calculated descriptor values from FLIM (Fluorescence lifetime imaging microscopy) and AF (autofluorescence) retinal diagnostics for real-time quantification of the treatment effect.

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-05-03
    DOI: 10.14278/rodare.969
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32599
Publ.-Id: 32599


IV-data for Complex Metal Nanostructures with Programmable Shapes from Simple DNA Building Blocks

Jain, A.; Bayrak, T.; Erbe, A.

IV-curves measured on self-organized Au nanogaps. HSQ-wires are 10 nm gaps without DNA molecules, to characterise the insulating properties of HSQ resist. Au_nanowire are measurements of continuous Au nanowires. The temperature dependent measurements characterize self-organised Au contacts to DNA ensembles with 10 nm length

Keywords: Nanoelectronics; Self-Organisation; DNA Origami

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-05-03
    DOI: 10.14278/rodare.967

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32598
Publ.-Id: 32598


A novel approach for the geospatial modelling and resource assessment of tailings storage facilities

Blannin, R.; Frenzel, M.; Gutzmer, J.

Tailings are the fine-grained residues of ore processing operations, typically stored in dedicated tailings storage facilities (TSFs). Despite being viewed as ‘waste’ materials, tailings can contain significant amounts of valuable metals which were not recovered by original processing techniques or were previously not of economic interest. Re-processing of tailings deposits for the recovery of remaining metals has the additional benefits of mitigation of environmental hazards posed by the TSFs, such as Acid Mine Drainage (AMD). The estimation of mineral resources requires the construction of accurate and reproducible geospatial models. However, the sedimentary-style deposition and subsequent weathering of tailings results in a complex internal structure which is challenging to model, with a laterally and vertically heterogeneous distribution of the minerals comprising the residues. The present study investigates a novel approach for the geospatial modelling of a TSF case study. The surface of the tailings deposit was densely sampled in order to assess the intrinsic horizontal variability. Drill core samples were taken from a depth of 1-3 m, on a 30 m grid and nested grids of 15 m and 7.5 m, with additional random and twin holes. The entire depth of the TSF was sampled in 2 m intervals with a total of 10 drill holes to assess vertical variability. All drill core samples were analysed with x-ray fluorescence spectrometry and inductively coupled plasma mass spectrometry. The compositional data was log-ratio-transformed and variography and subsequent ordinary kriging and co-kriging were performed on the surface samples. The variogram models obtained for the surface samples were then applied for kriging of the deeper layers. Historical photographs of the surface of the TSF were used to improve estimates with co-kriging for the corresponding layers. The entire data set will be used to determine the most efficient sampling approach for the resource estimation of TSFs.

  • Open Access Logo Contribution to proceedings
    European Geosciences Union General Assembly 2021, 26.-30.04.2021, Vienna, Austria
    DOI: 10.5194/egusphere-egu21-2992

Permalink: https://www.hzdr.de/publications/Publ-32595
Publ.-Id: 32595


SEM-EDS datasets of titanium alloy wear debris in periprosthetic tissue

Podlipec, R.; Pirker, L.

SEM-EDS images and datasets of titanium alloy wear debris found in periprosthetic tissue obtained at revision surgery of a fractured titanium-alloy modular neck of a patient with hip osteoarthritis.

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-30
    DOI: 10.14278/rodare.965
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32582
Publ.-Id: 32582


Pump-probe data for "A Two‐Dimensional Polyimide‐Graphene Heterostructure with Ultra‐fast Interlayer Charge Transfer"

Li, J.; Pashkin, O.; Schneider, H.; Helm, M.

Pump-probe traces of transient absorption change for graphene, protonated 2DPI and protonated 2DPI on graphene

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-30
    DOI: 10.14278/rodare.963

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32581
Publ.-Id: 32581


Data for: Sensitivity of PS/CoPd Janus particles to an external magnetic field

Eichler-Volf, A.; Alsaadawi, Y.; Vazquez Luna, F.; Khan, Q. A.; Stierle, S.; Xu, C.; Heigl, M.; Fekri, Z.; Zhou, S.; Zahn, P.; Albrecht, M.; Steinhart, M.; Erbe, A.

Movies show the 90-degrees rotation of PS/CoPd Janus particles in weak and strong magnetic fields

EDX/SEM/XRD data were used  to characterize the the CoPd particles

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-29
    DOI: 10.14278/rodare.959
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32578
Publ.-Id: 32578


HELIPORT (HELmholtz ScIentific Project WORkflow PlaTform)

Voigt, M.; Ufer, R.; Schacht, W.; Knodel, O.; Pape, D.; Lokamani, M.; Müller, S.

The guidance system HELIPORT aims to make the entire life cycle of a project at the HZDR searchable, accessible, complete and reusable according to the FAIR principles, mentioned below. In particular, our data management solution deals with the areas from the generation of the data to the publication of primary research data, the workflows carried out and the actual research results. For this purpose, a concept was developed which shows the various essential components and their connections. Descriptions of the individual components can be found in our RODARE publication: 10.14278/rodare.252

Keywords: metadata; HELIPORT; project livecycle; FAIR; data managment

  • Software in the HZDR data repository RODARE
    Publication date: 2021-04-19
    DOI: 10.14278/rodare.946
    License: GPL-3.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32577
Publ.-Id: 32577


Update on Radiation Studies for MU2E-II (and MU2E)

Müller, S.

Presentation at "Mu2e-II Snowmass22 Workshop", 28.04.2021

Keywords: FLUKA; MU2E

  • Lecture (Conference) (Online presentation)
    Mu2e-II Snowmass22 Workshop, 28.04.2021, FERMILAB (virtual), USA

Permalink: https://www.hzdr.de/publications/Publ-32576
Publ.-Id: 32576


Data for: Comparison of Elemental Analysis Techniques for the Characterization of Commercial Alloys

Seidel, P.

The uploaded XRF, OES, and LIBS data served as base for the publication by Seidel et al. 2021 in the journal Metals.

Keywords: Metals; Element analysis; XRF

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-29
    DOI: 10.14278/rodare.957
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32575
Publ.-Id: 32575


Large eddy simulation of the fluid–structure interaction in an abstracted aquatic canopy consisting of flexible blades

Tschisgale, S.; Löhrer, B.; Meller, R.; Fröhlich, J.

The paper addresses the fluid–structure interaction of submerged aquatic canopies, with particular focus on the complex interplay between coherent flow structures and the motion of vegetation elements. New insights into the underlying mechanisms are gained from a large eddy simulation of a submerged model canopy flow. The model canopy is made up of 800 highly flexible blades, each individually resolved by an immersed boundary method. The obtained high-resolution flow data reveal well-known coherent turbulent structures, including velocity streaks, Kelvin–Helmholtz (KH) vortices in the mixing layer as well as hairpin (HP) vortices in the outer flow region. The present results show that the interaction of these prototypical structures plays a key role creating unique turbulent features such as composite KH/HP vortices located between a high-speed and low-speed streak. Under the influence of these pronounced eddies, groups of blades respond by a strong local reconfiguration. Due to the convection of the coherent structures by the mean flow this causes an apparent wave-like motion of the canopy in streamwise direction, known as monami. A frequency analysis of this phenomenon shows that the vegetation responds almost passively, merely reflecting local flow conditions.

Keywords: flow–structure interactions; turbulent boundary layers

Permalink: https://www.hzdr.de/publications/Publ-32572
Publ.-Id: 32572


Reactivation of magma pathways: Insights from field observations, geochronology, geomechanical tests and numerical models

Thiele, S. T.; Cruden, A. R.; Zhang, X.; Micklethwaite, S.; Matchan, E. L.

Field observations and unmanned aerial vehicle surveys from Caldera Taburiente (La Palma, Canary Islands, Spain) show that pre-existing dykes can capture and re-direct younger ones to form multiple dyke composites. Chill margins suggest that the older dykes were solidified and cooled when this occurred. In one multiple dyke example, an 40Ar/39Ar age difference of 200 kyr was determined between co-located dykes. Petrography and geomechanical measurements (ultrasonic pulse and Brazilian disc tests) show that a microscopic preferred alignment of plagioclase laths and sheet-like structures formed by non-randomly distributed vesicles give the solidified dykes anisotropic elastic moduli and fracture toughness. We hypothesise that this anisotropy led to the development of margin-parallel joints within the dykes, during subsequent volcanic loading. Finite element models also suggest that the elastic contrast between solidified dykes and their host rock elevated and re-oriented the stresses that governed subsequent dyke propagation. Thus, the margin-parallel joints, combined with local concentration and rotation of stresses, favoured the deflection of subsequent magma-filled fractures by up to 60° to form the multiple dykes. At the edifice scale, the capture and deflection of active intrusions by older ones could change the organisation of volcanic magma plumbing systems and cause unexpected propagation paths relative to the regional stress. We suggest that reactivation of older dykes by this mechanism gives the volcanic edifice a structural memory of past stress states, potentially encouraging the re-use of older vents and deflecting intrusions along volcanic rift zones or towards shallow magma reservoirs.

Keywords: multiple dyke; elastic anisotropy; fracture deflection; mechanical discontinuity; reactivation; Quaternary; basalt Ar-Ar dating; Canary Islands

  • Open Access Logo Journal of Geophysical Research - Solid Earth (2021)
    Online First (2021) DOI: 10.1029/2020JB021477

Permalink: https://www.hzdr.de/publications/Publ-32563
Publ.-Id: 32563


Origin of the 30 T transition in CeRhIn5 in tilted magnetic fields

Mishra, S.; Gorbunov, D.; Campbell, D. J.; Leboeuf, D.; Hornung, J.; Klotz, J.; Zherlitsyn, S.; Harima, H.; Wosnitza, J.; Aoki, D.; McCollam, A.; Sheikin, I.

We present a comprehensive ultrasound study of the prototypical heavy-fermion material CeRhIn5, examining the origin of the enigmatic 30 T transition. For a field applied at 2° from the c axis, we observed two sharp anomalies in the sound velocity, at Bm ≈ 20 T and B ≈ 30 T, in all the symmetry-breaking ultrasound modes at low temperatures. The lower-field anomaly corresponds to the well-known first-order metamagnetic incommensurate-to-commensurate transition. The higher-field anomaly takes place at 30 T, where an electronic-nematic transition was previously suggested to occur. Both anomalies, observed only within the antiferromagnetic state, are of similar shape, but the corresponding changes of the ultrasound velocity have opposite signs. Based on our experimental results, we suggest that a field-induced magnetic transition from a commensurate to another incommensurate antiferromagnetic state occurs at B. With further increasing the field angle from the c axis, the anomaly at B slowly shifts to higher fields, broadens, and becomes smaller in magnitude. Traced up to 30° from the c axis, it is no longer observed at 40° below 36 T.

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Permalink: https://www.hzdr.de/publications/Publ-32559
Publ.-Id: 32559


Accelerator Programming Using Directives 7th International Workshop, WACCPD 2020, Virtual Event, November 20, 2020, Proceedings

Bhalachandra, S.; Wienke, S.; Chandrasekaran, S.; Juckeland, G.

This book constitutes the proceedings of the 7th International Workshop on Accelerator Programming Using Directives, WACCPD 2020, which took place on November 20, 2021. The workshop was initially planned to take place in Atlanta, GA, USA, and changed to an online format due to the COVID-19 pandemic.
WACCPD is one of the major forums for bringing together users, developers, and the software and tools community to share knowledge and experiences when programming emerging complex parallel computing systems. The 5 papers presented in this volume were carefully reviewed and selected from 7 submissions. They were organized in topical sections named: OpenMP; OpenACC; and Domain-specific Solvers.

Keywords: Compilers; computer networks; CUDA; distributed computer systems; embedded systems; Graphics Processing Unit (GPU); Hardware accelerators; Heterogeneous (hybrid) systems; Massively parallel algorithms; Massively parallel and high-performance simulations

Permalink: https://www.hzdr.de/publications/Publ-32558
Publ.-Id: 32558


Die Rolle von Mikroorganismen bei der Lagerung von hoch-radioaktiven Abfällen - Mikrobiologie am HZDR

Matschiavelli, N.

Durch den Ausstieg Deutschlands aus der Kernkraft tritt immer mehr die dauerhafte und sichere Lagerung der noch hoch-radioaktiven Brennelemente in den Fokus. Aber wie beeinflussen Mikroorganismen die Metalle und Gesteine, aus denen ein Endlager aufgebaut ist? Als Mikrobiologen/innen in der Abteilung für Biogeochemie zeigen wir dir, wie mit modernen biologischen Methoden diese Fragen beantwortet werden.

  • Lecture (others) (Online presentation)
    Gils`& Boys`day am HZDR, 22.04.2021, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-32556
Publ.-Id: 32556


Proton beam quality enhancement by spectral phase control of a PW-class laser system

Ziegler, T.; Albach, D.; Bernert, C.; Bock, S.; Brack, F.-E.; Cowan, T. E.; Dover, N. P.; Garten, M.; Gaus, L.; Gebhardt, R.; Goethel, I.; Helbig, U.; Irman, A.; Kiriyama, H.; Kluge, T.; Kon, A.; Kraft, S.; Kroll, F.; Loeser, M.; Metzkes-Ng, J.; Obst-Huebl, L.; Püschel, T.; Rehwald, M.; Schlenvoigt, H.-P.; Schramm, U.; Zeil, K.

This repository contains the experimental raw data, the analyzed data and corresponding scripts as well as figures for the "Proton beam quality enhancement by spectral phase control of a PW-class laser system" publication.

https://doi.org/10.1038/s41598-021-86547-x

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-01
    DOI: 10.14278/rodare.953
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32554
Publ.-Id: 32554


ExPaNDS Training Catalogue Demo

Knodel, O.

This entry contains a demo video introducing the ExPaNDS/PaNOSC training catalogue developed by HZDR.

Keywords: data management; training; ExPaNDS

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-19
    DOI: 10.14278/rodare.942
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32553
Publ.-Id: 32553


Thermocapillary Effects at Gas Bubbles Growing on Electrodes

Mutschke, G.; Hossain, S. S.; Bashkatov, A.; Yang, X.; Eckert, K.

The contribution summarizes recent progress obtained in our group when studying the dynamics of
hydrogen gas bubbles growing during electrolysis in an aqueous electrolyte. We find that thermocapillary
effects are important to be considered, which lead to characteristic vortical electrolyte flow close to the
bubble [1,2]. We further discuss the resulting force on the bubble and conclude on how the bubble
departure is affected at electrodes of different sizes [3]. This knowledge might contribute to advancing
the efficiency of electrolyzers.

References:
[1] X. Yang et al., Marangoni convection at electrogenerated hydrogen bubbles, Phys. Chem. Chem.
Phys. 20 (2018) 11542.
[2] J. Massing et al., Thermocapillary convection during hydrogen evolution at microelectrodes,
Electrochim. Acta 297 (2019) 929-940.
[3] S.S. Hossain et al., On the thermocapillary effect on gas bubbles growing on electrodes of different
sizes, Electrochim. Acta 353 (2020) 136461.

Keywords: electrolysis; water splitting; gas evolution; thermocapillary effect

  • Lecture (Conference) (Online presentation)
    29th Topical Meeting of the International Society of Electrochemistry, 19.-21.04.2021, Mikulov, Tschechische Republik

Permalink: https://www.hzdr.de/publications/Publ-32552
Publ.-Id: 32552


Macro to generate muon (g-2) summary plot

Müller, S.

This macro gives the status of the muon (g-2) just after the FERMILAB seminar on April 7, 2021.

The theoretical values use the different contributions as given in the

[White Paper](https://arxiv.org/pdf/2006.04822.pdf) of the

[Theory Initiative](https://muon-gm2-theory.illinois.edu/). Since the leading

order hadronic contribution is dominating the uncertainty of the

theoretical values, several values for a$_\mu$ are plotted which use the

different evaluations for the leading order hadronic contribution given in

Table 4 of the White Paper as well as the White Paper average.

Keywords: ROOT; (g-2); Macro

  • Software in the HZDR data repository RODARE
    Publication date: 2021-04-21
    DOI: 10.14278/rodare.950
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32551
Publ.-Id: 32551


A Two‐Dimensional Polyimide‐Graphene Heterostructure with Ultra‐fast Interlayer Charge Transfer

Liu, K.; Li, J.; Qi, H.; Hambsch, M.; Rawle, J.; Romaní Vázquez, A.; Shaygan Nia, A.; Pashkin, O.; Schneider, H.; Polozij, M.; Heine, T.; Helm, M.; Mannsfeld, S. C. B.; Kaiser, U.; Dong, R.; Feng, X.

Two‐dimensional polymers (2DPs) are a class of atomically/molecularly thin crystalline organic 2D materials. They are intriguing candidates for the development of unprecedented organic‐inorganic 2D van der Waals heterostructures (vdWHs) with exotic physicochemical properties. In this work, we demonstrate the on‐water surface synthesis of large‐area (cm 2 ), monolayer 2D polyimide (2DPI) with 3.1‐nm lattice. Such 2DPI comprises metal‐free porphyrin and perylene units linked by imide bonds. We further achieve a scalable synthesis of 2DPI‐graphene (2DPI‐G) vdWHs via a face‐to‐face co‐assembly of graphene and 2DPI on the water surface. Remarkably, femtosecond transient absorption spectroscopy reveals an ultra‐fast interlayer charge transfer (~60 fs) in the resultant 2DPI‐G vdWH upon protonation by acid, which is equivalent to that of the fastest reports among inorganic 2D vdWHs. Such large interlayer electronic coupling is ascribed to the interlayer cation‐π interaction between 2DP and graphene. Our work opens opportunities to develop 2DP‐based vdWHs via the on‐water surface synthesis strategy and highlights the unique interface‐induced optoelectronic properties.

Keywords: 2D polymer; graphene; van der Waals heterostructure; transient absorption spectroscopy

Related publications

Permalink: https://www.hzdr.de/publications/Publ-32550
Publ.-Id: 32550


A tunable autocorrelator for pulse measurements at IR FEL-oscillator facilities

Cicek, E.; Seidel, W.; Ketenoglu, B.

Radiation characteristics of a Free-Electron Laser (FEL) such as pulse length, timestructure, intensity, bandwidth, wavelength, power, frequency, etc., which were measured on adiagnostics table, are thoroughly discussed. In this respect, pulse length measurements of an InfraredFEL (IR-FEL) beam are evaluated through an intensity autocorrelator, designed and installed as adiagnostics tool at the “Helmholtz-Zentrum Dresden-Rossendorf (HZDR)-Radiation Source ELBE”of Germany. In addition, the autocorrelator was designed as a unique, cost-effective, and in-housesetup. It operates within the wavelength range of 3–35 microns, using Cadmium-Telluride (CdTe)crystals in the Second Harmonic Generation (SHG) medium. The intensity autocorrelation curveswere obtained for the FEL beam with the wavelength of 26.2 microns, indicating an FWHM pulseduration ranging between 3.29–8.03 ps with different optical cavity detuning values. Furthermore,the pulse duration of Ti: sapphire laser beam is measured between 1–3 ps through the designedautocorrelator at the ELBE light source. On the other hand, the setup may pave the way for pulselength measurements of the Turkish infrared FEL-oscillator facility (TARLA) as well, which iscurrently under the hardware installation phase. Finally, it is elaborated in section 3 that the uniqueautocorrelator design fully meets all requirements for pulse length measurements of an infraredFEL source.Radiation characteristics of a Free-Electron Laser (FEL) such as pulse length, timestructure, intensity, bandwidth, wavelength, power, frequency, etc., which were measured on adiagnostics table, are thoroughly discussed. In this respect, pulse length measurements of an InfraredFEL (IR-FEL) beam are evaluated through an intensity autocorrelator, designed and installed as adiagnostics tool at the “Helmholtz-Zentrum Dresden-Rossendorf (HZDR)-Radiation Source ELBE”of Germany. In addition, the autocorrelator was designed as a unique, cost-effective, and in-housesetup. It operates within the wavelength range of 3–35 microns, using Cadmium-Telluride (CdTe)crystals in the Second Harmonic Generation (SHG) medium. The intensity autocorrelation curveswere obtained for the FEL beam with the wavelength of 26.2 microns, indicating an FWHM pulseduration ranging between 3.29–8.03 ps with different optical cavity detuning values. Furthermore,the pulse duration of Ti: sapphire laser beam is measured between 1–3 ps through the designedautocorrelator at the ELBE light source. On the other hand, the setup may pave the way for pulselength measurements of the Turkish infrared FEL-oscillator facility (TARLA) as well, which iscurrently under the hardware installation phase. Finally, it is elaborated in section 3 that the uniqueautocorrelator design fully meets all requirements for pulse length measurements of an infraredFEL source.

Keywords: Beam-line instrumentation (beam position and profile monitors; beam-intensity monitors; bunch lengt

Permalink: https://www.hzdr.de/publications/Publ-32549
Publ.-Id: 32549


The Helmholtz cloud services as well suited platform for sustainable OpenFOAM_RCS development

Schlegel, F.; Greenshields, C.; Huste, T.; Lehnigk, R.; Lucas, D.; Peltola, J.

The presentation gives a comprehensive overview about sustainable software development strategies for OpenFOAM_RCS and how this will be supported by the Helmholtz cloud services in the frame of HIFIS.

Keywords: OpenFOAM; HIFIS; Computational Fluid Dynamics; software development

  • Lecture (Conference) (Online presentation)
    32nd Meeting of German CFD Network of Competence, 16.-17.03.2021, München, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-32544
Publ.-Id: 32544


Experimental electronic stopping cross section of tungsten for light ions in a large energy interval

Moro, M. V.; Wolf, P. M.; Bruckner, B.; Munnik, F.; Heller, R.; Bauer, P.; Primetzhofer, D.

Electronic stopping cross section of tungsten for light ions was experimentally measured in a wide energy interval (20 to 6000 keV for protons and 50 to 9000 keV for helium) in backscattering and transmission geometries. The measurements were carried out in three laboratories (Austria, Germany and Sweden) using five different set-ups, the stopping data deduced from different data sets showed excellent agreement amongst each other, with total uncertainty varying within 1.5–3.8% for protons and 2.2–5.5% for helium, averaged over the respective energy range of each data set. The final data is compared to available data and to widely adopted semi-empirical and theoretical approaches, and found to be in good agreement with most adopted models at energies around and above the stopping maximum. Most importantly, our results extend the energy regime towards lower energies, and are thus of high technological relevance, e.g., in fusion research. At these low energies, our findings also revealed that tungsten – featured with fully and partially occupied f- and d-subshells, respectively – can be modeled as an electron gas for the energy loss process.

Keywords: Stopping power; Tungsten; Free electron gas; Bragg peak; Protons; Helium; Fusion

Permalink: https://www.hzdr.de/publications/Publ-32543
Publ.-Id: 32543


Data/Software for: Dynamics of mono- and poly-disperse two-dimensional foams flowing in an obstructed channel

Lecrivain, G.

This archive contains the raw data and the original code described in the manuscript "Dynamics of mono- and poly-disperse two-dimensional foams flowing in an obstructed channel", submitted in 2020 to Journal of Fluid Mechanics by Thales Carl Lavoratti, Sascha Heitkam, Uwe Hampel, and Gregory Lecrivain. The archive contains the following data:

- C++ code used to simulate the foam dynamics and create the raw data (petsc.tar.gz)

- selected raw data in petsc format. The mono-disperse scenarios V125.tar.gz, V200.tar.gz, V250.tar.gz, V350.tar.gz correspond to the gas fractions \varepsilon = 0.44, 0.68, 0.83, and 0.99, respectively. The poly-disperse scenarios V125r.tar.gz, V200r.tar.gz, V250r.tar.gz, V350r.tar.gz correspond to the gas fractions 0.44, 0.69, 0.84, and 0.99, respectively

- bash and python scripts used to create bubble contours from the petsc raw data (scripts.tar.gz)

- extracted bubble contours (contours.tar.gz)

- python codes used to make figures and animations (figures.tar.gz)

- Mathematica notebook testing the wall potential f(\phi_w) = 0 (potential.nb)

- manuscript data (manuscript.tar.gz)

For further questions, feel free to contact me (g.lecrivain@hzdr.de).

Keywords: Flowing foam; Phase-field simulation; Obstructed channel

  • Software in the HZDR data repository RODARE
    Publication date: 2021-01-12
    DOI: 10.14278/rodare.738
    License: CC-BY-4.0
    Embargo: 30.06.2021

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Permalink: https://www.hzdr.de/publications/Publ-32542
Publ.-Id: 32542


Speciation of Pd in minerals from Norilsk ores by X-ray absorption spectroscopy

Brovchenko, V. D.; Merkulova, M.; Sittner, J.; Renno, A. D.

Определены спектры рентгеновского поглощения (XANES) для Pd в пентландите, Pd в металлической форме (Pd фольга) и Pd в минералах платиновой группы, показывающие большие различия в форме всех спектров. Доказано, что палладий в пентландите не имеет ни металлической формы, ни микропримесей минералов платиновой группы, но входит в кристаллическую решетку пентландита. Энергетическое положение белой линии (3173.8 eV) спектра Pd в пентландите аналогично положению белой линии спектров Pd в минералах платиновой группы. Это свидетельствует о том, что палладий в пентландите имеет номинальное состояние окисления +2. Поэтому можно предположить, что палладий замещает атомы железа или никеля в кристаллической структуре пентландита.
X-ray absorption spectra (XANES) for Pd in pentlandite, Pd in metallic form (Pd foil) and Pd in platinum-group minerals were determined showing large differences in the shape of all spectra. It was proved that palladium in pentlandite is neither in its metal form nor in microinclusions of platinum-group minerals, but is included in the crystal lattice of pentlandite. Energy position of white line (3173.8 eV) of Pd spectrum in pentlandite is similar to the position of white line of Pd spectra in platinum group minerals. This indicates that palladium in pentlandite has a nominal oxidation state of +2. Therefore, we can assume that palladium replaces iron or nickel atoms in the crystal structure of pentlandite.

Keywords: Norilsk; X-Ray Absorption Spectroscopy; Palladium; Pentlandite

  • Open Access Logo Lecture (Conference)
    Металлогения древних и современных океанов – 2021. Сингенез, эпигенез, гипергенез Metallogeny of ancient and modern oceans - 2021. Syngenesis, epigenesis, hypergenesis, 26.-30.04.2021, Миасс - Miass, Russland

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Permalink: https://www.hzdr.de/publications/Publ-32538
Publ.-Id: 32538


Example Project Plan generated by HELIPORT

Voigt, M.; Knodel, O.

This dataset contains the metadata for an example project generated using the project export button in our prototype scientific project lifecycle and workflow management system HELIPORT (HELmholtz ScIentific Project WORkflow PlaTform). The metadata schema is still under development and this entry will be updated to reflect further developments.

Keywords: metadata; HELIPORT; project livecycle; FAIR

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-16
    DOI: 10.14278/rodare.938
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32537
Publ.-Id: 32537


3D CT image

Da Assuncao Godinho, J. R.

3D image, experiment 2

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-08
    DOI: 10.14278/rodare.918
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32534
Publ.-Id: 32534


Dataset for: Chemical absorption measurements in a lab scale bubble column

Kipping, R.; Hampel, U.

This data set contains gas phase hydrodynamic data obtained from ultrafast X-ray tomography measurements in a bubble column. Global and local gas holdups, as well as bubble size distributions are given for I) non reactive conditions with nitrogen (gas) and sodium hydroxide solution (liquid) and II) reactive conditions with carbon dioxide (gas) and sodium hydroxide solution (liquid). Additionally the data set contains the corresponding consumption rates obtained from wire-mesh sensor measurements.

Furhter details on the experiments are explained in the corresponding journal paper.

Keywords: bubble columns; wire-mesh sensor; UFXCT

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-13
    DOI: 10.14278/rodare.924

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Permalink: https://www.hzdr.de/publications/Publ-32533
Publ.-Id: 32533


Advancing laser plasma accelerators by means of femto-scale diagnostics for a pilot study of high dose rate in-vivo irradiation

Schramm, U.

Talk on Advancing laser plasma accelerators by means of femto-scale diagnostics for a pilot study of high dose rate in-vivo irradiation

Keywords: laser proton acceleration; high dose rate radiobiology

  • Invited lecture (Conferences) (Online presentation)
    4th international symposium on high power laser science and engineering, HPLSE, 12.-15.04.2021, Suzhou, China

Permalink: https://www.hzdr.de/publications/Publ-32531
Publ.-Id: 32531


Data for: Electron dose rate and oxygen depletion protect zebrafish embryos from radiation damage

Pawelke, J.; Brand, M.; Hans, S.; Hideghéty, K.; Karsch, L.; Leßmann, E.; Löck, S.; Schürer, M.; Szabo, E. R.; Beyreuther, E.

Primary data and data description to publication:

Electron dose rate and oxygen depletion protect zebrafish embryos from radiation damage

Abstract:

Background and purpose
In consequence of a previous study, where no protecting proton Flash effect was found for zebrafish embryos, potential reasons and requirements for inducing a Flash effect should be investigated with the beam pulse structure and the partial oxygen pressure (pO2) as relevant parameters.
Materials and methods
The experiments were performed at the research electron accelerator ELBE, whose variable pulse structure enables dose delivery as electron Flash and quasi-continuously (reference). Zebrafish embryos were irradiated with ~26 Gy either continuously with a dose rate of ~6.7 Gy/min or in one 111 µs long pulse with a pulse dose rate of 109 Gy/s and a mean dose rate of 105 Gy/s, respectively. Using the OxyLite system to measure the pO2 a low- (pO2 ≤ 5 mmHg) and a high-pO2 group were defined on basis of the oxygen depletion kinetics in sealed embryo samples.
Results
A protective Flash effect was seen for most endpoints ranging from 4 % less reduction in embryo length to about 20 – 25 % less embryos with spinal curvature and pericardial edema, relative to reference irradiation. The reduction of pO2 below atmospheric levels (148 mmHg) resulted in higher protection, which was however more pronounced in the low-pO2 group.
Conclusion
The Flash experiment at ELBE showed that the zebrafish embryo model is appropriate for studying the radiobiological response of high dose rate irradiation. Pulse dose and pulse dose rate as important beam parameters were confirmed as well as the pivotal role of pO2 during irradiation.

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-15
    DOI: 10.14278/rodare.928

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Permalink: https://www.hzdr.de/publications/Publ-32529
Publ.-Id: 32529


A Robust PtNi Nanoframe/N-Doped Graphene Aerogel Electrocatalyst with Both High Activity and Stability

Yang, J.; Hübner, R.; Zhang, J.; Wan, H.; Zheng, Y.; Wang, H.; Qi, H.; He, L.; Li, Y.; Aregahegn Dubale, A.; Sun, Y.; Liu, Y.; Peng, D.; Meng, Y.; Zheng, Z.; Rossmeisl, J.; Liu, W.

Insufficient catalytic activity and stability and high cost are the barriers for Pt-based electrocatalysts in wide practical applications. Herein, a hierarchically porous PtNi nanoframe/N-doped graphene aerogel (PtNiNF-NGA) electrocatalyst with outstanding performance toward methanol oxidation reaction (MOR) in acid electrolyte has been developed via facile tert-butanol-assisted structure reconfiguration. The ensemble of high-alloying-degree-modulated electronic
structure and correspondingly the optimum MOR reaction pathway, the structure superiorities of hierarchical porosity, thin edges, Pt-rich corners, and the anchoring effect of the NGA, endow the PtNiNF-NGA with both prominent electrocatalytic activity and stability. The mass and specific activity (1647 mAmgPt -1, 3.8 mAcm-2) of the PtNiNF-NGA are 5.8 and 7.8 times higher than those of commercial Pt/C. It exhibits exceptional stability under a 5-hour chronoamperometry test and 2200-cycle cyclic voltammetry scanning.

Permalink: https://www.hzdr.de/publications/Publ-32527
Publ.-Id: 32527


Didier L. BOURLÈS (1955-2021), the 5 MV cosmogenic rock star

Braucher, R.; Blard, P.-H.; Brown, E. T.; Carcaillet, J.; Lebatard, A.-E.; Siame, L.; Simon, Q.; Thouveny, N.; Aumaître, G.; Bard, E.; Carretier, S.; Cornu, S.; Fink, D.; Finkel, R.; German, C.; Godard, V.; Hamelin, B.; Hofmann, F. M.; Jomelli, V.; Keddadouche, K.; Kurz, M. D.; Palacios, D.; Measures, C.; Merchel, S.; Regard, V.; Schimmelpfennig, I.; von Blanckenburg, F.; Zerathe, S.

paper without abstract

Permalink: https://www.hzdr.de/publications/Publ-32526
Publ.-Id: 32526


Metal-induced progressive alteration of conducting states in memristors for implementing an efficient analog memory: a DFT-supported experimental approach

Das, D.; Barman, A.; Sarkar, P. K.; Rajput, P.; Jha, S. N.; Hübner, R.; Kanjilal, D.; Johari, P.; Kanjilal, A.

Advancement of the memristor-based artificial synapse (AS) is urgently needed for rapid progress in neuromorphic devices. The precise structural and chemical engineering of metal oxide layers by metal dopants (Ni) is presented as an innovative way to set off a decent performance of the AS. An ON/OFF ratio of 103 as well as data retention and endurance capabilities of 104 s and 103 cycles, respectively, are achieved. With these properties, the symmetric alteration in conductance states, short-term plasticity (STP) and long-term plasticity (LTP) are realized within the same device, and compared with the reported values to establish its excellent cognitive behavioural ability. Our combined experimental and the DFT-based first-principles calculation results reveal that the rational designing of AS using metal cations (Ni) can promote an ultra-low-power of about 2.55 fJ per pulse (lower than human brain about 10 fJ per pulse) for STP, promising for next-generation smart memory devices. Here, Ni endorses strong electronic localization, which in turn familiarizes trap states within the forbidden energy gap and improves short-term memory loss. Further, it modifies the local electrostatic barriers to stimulate modulatory action (as commonly observed in the mammalian brain) for LTP. Overall, this work provides a novel pathway to overcome the technological bottleneck.

Permalink: https://www.hzdr.de/publications/Publ-32523
Publ.-Id: 32523


Electric Quadrupolar Contributions in the Magnetic Phases of UNi4B

Yanagisawa, T.; Matsumori, H.; Saito, H.; Hidaka, H.; Amitsuka, H.; Nakamura, S.; Awaji, S.; Gorbunov, D.; Zherlitsyn, S.; Wosnitza, J.; Uhlirova, K.; Valiska, M.; Sechovsky, V.

We present acoustic signatures of the electric quadrupolar degrees of freedom in the honeycomb-layer compound UNi4B. The transverse ultrasonic mode C66 shows softening below 30 K both in the paramagnetic phase and antiferromagnetic phases down to ∼0.33 K. Furthermore, we traced magnetic field-temperature phase diagrams up to 30 T and observed a highly anisotropic elastic response within the honeycomb layer. These observations strongly suggest that Γ6 (E2g) electric quadrupolar degrees of freedom in localized 5f2 (J = 4) states are playing an important role in the magnetic toroidal dipole order and magnetic-field-induced phases of UNi4B, and evidence some of the U ions remain in the paramagnetic state even if the system undergoes magnetic toroidal ordering.

Permalink: https://www.hzdr.de/publications/Publ-32522
Publ.-Id: 32522


Data for: Effective diffusivity prediction of radionuclides in clay formations using an integrated upscaling workflow

Yuan, T.; Fischer, C.

The effective diffusivity is a key parameter in the diffusive transport calculations, thus decisive for predicting the radionuclide migration in low-permeable clay-rich formations. Potential host rocks such as the Opalinus clay exhibit pore network heterogeneities, critically modified due to compositional variability in the sandy facies and owing to diagenetic minerals. Meaningful estimation of the effective diffusivity requires an understanding of transport mechanisms at the nanometer-scale as a starting point and a combination with upscaling strategies for considering compositional heterogeneities at the micrometer-scale.

In this study, we propose an upscaling workflow that integrates transport simulations at both the nanometer-scale and the micrometer-scale to predict the effective diffusivities of radionuclides in the sandy facies of the Opalinus clay. The respective synthetic digital rocks provide conceptually two types of materials at the pore scale, in which the pore space and pore network in the clay matrix at the nanometer scale and mineral complexity in shales at the micrometer scale are considered. The numerical approach using the introduced digital rocks is validated with published experimental data that confirm the general applicability of the models. Sensitivity studies reveal the increase of effective diffusivity of shales as a function of increased pore space, reduced tortuosity, and an increased sheet silicate concentration compared to other rock components. Thus, such spatial variabilities at the pore scale of more complex sedimentary rocks are now addressed in the proposed approach and available for studying heterogeneous diffusion patterns compared to commonly assumed homogeneous behavior. Finally, and as a starting point for further upscaling strategies, we investigate anisotropic diffusion by studying the effect of lamination of the shales towards enhanced predictability of radionuclide migration.

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-13
    DOI: 10.14278/rodare.922

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Permalink: https://www.hzdr.de/publications/Publ-32519
Publ.-Id: 32519


Boundary conditions for the Neel order parameter in a chiral antiferromagnetic slab

Pylypovskyi, O.; Tomilo, A.; Sheka, D.; Faßbender, J.; Makarov, D.

Understanding of the interaction of antiferromagnetic solitons including domain walls and skyrmions with boundaries of chiral antiferromagnetic slabs is important for the design of prospective antiferromagnetic spintronic devices. Here, we derive the transition from spin lattice to micromagnetic nonlinear σ model with the corresponding boundary conditions for a chiral cubic G-type antiferromagnet and analyze the impact of the slab boundaries and antisymmetric exchange (Dzyaloshinskii-Moriya interaction) on the vector order parameter. We apply this model to evaluate modifications of antiferromagnetic domain walls and skyrmions upon interaction with boundaries for different strengths of the antisymmetric exchange. Due to the presence of the antisymmetric exchange, both types of antiferromagnetic solitons become broader when approaching the boundary and transform to a mixed Bloch-Néel structure. Both textures feel the boundary at the distance of about five magnetic lengths. In this respect, our model provides design rules for antiferromagnetic racetracks, which can support bulklike properties of solitons.

Keywords: antiferromagnetism; slab; Dzyaloshinskii-Moriya interaction; domain wall; skyrmion

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Permalink: https://www.hzdr.de/publications/Publ-32511
Publ.-Id: 32511


Effects of geometry on curvilinear antiferromagnetic spin chains

Pylypovskyi, O.; Kononenko, D. Y.; Yershov, K.; Roessler, U. K.; Faßbender, J.; van den Brink, J.; Makarov, D.; Sheka, D.

Antiferromagnets are technologically promising materials for spintronic and spinorbirtonic devices [1]. An efficient manipulation of antiferromagnetic textures requires the presence of the Dzyaloshinskii-Moriya interaction (DMI), which is present in crystals of special symmetry, and thus limits the number of available materials. In contrast to antiferromagnets, it is already established that in ferromagnetic thin films and nanowires chiral responses can be tailored relying on curvilinear geometries [2]. Here, we explore geometry-induced effects in curvilinear antiferromagnets. We demonstrate theoretically that intrinsically achiral curvilinear antiferromagnetic spin chains behave as a biaxial chiral helimagnet with a curvature-tunable anisotropy and DMI [3]. The geometry-driven easy axis anisotropy determines the homogeneous antiferromagnetic state at low curvatures and the gap for spin waves. The geometry-driven DMI determines the helimagnetic phase transition and leads to the appearance of the region with the negative group velocity at the dispersion curve.

[1] V. Baltz et al., Rev. Mod. Phys. 90, 015005 (2018).
[2] R. Streubel et al., J. Phys. D.: Appl. Phys. 49, 363001 (2016).
[3] O. V. Pylypovskyi et al., Nano Lett. (2020) DOI: 10.1021/acs.nanolett.0c03246.

Keywords: spin chain; antiferromagnetism; Dzyaloshinskii-Moriya interaction; curvilinear magnetism

  • Lecture (Conference) (Online presentation)
    APS March Meeting 2021, 15.-19.03.2021, Online, USA

Permalink: https://www.hzdr.de/publications/Publ-32510
Publ.-Id: 32510


Data for: Bubble formation from a microscale submerged orifice- A numerical approach

Mohseni, E.

We developed a mechanistic model for calculation of bubble volume from orifices in the range from 0.03 mm to 0.193 mm under the constant gas flow conditions in a quiescent liquid. It is known that for such small orifices, the mechanism of bubble formation is highly dependent on the gas momentum force and the liquid inertia force. Accordingly, the model incorporates these forces to calculate the bubble volume in three consecutive stages. Moreover, the model includes the influence of the bubble base expansion and bubble rising induced liquid velocity on the formation of bubbles. Eventually the model is validated with own experimental data using air and deionized water. Experimental validation of the model confirms that the maximum deviation of the model is less than 10%.

Keywords: Bubble formation; Micro-scale orifice; Mechanistic model; Stainless steel orifice; Force balance

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-07
    DOI: 10.14278/rodare.916

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Permalink: https://www.hzdr.de/publications/Publ-32507
Publ.-Id: 32507


Highly sensitive ²⁶Al measurements by Ion-Laser-InterAction Mass Spectrometry

Lachner, J.; Martschini, M.; Kalb, A.; Kern, M.; Marchhart, O.; Plasser, F.; Priller, A.; Steier, P.; Wieser, A.; Golser, R.

The method of Ion-Laser InterAction Mass Spectrometry (ILIAMS) offers new options for the determination of ²⁶Al by Accelerator Mass Spectrometry (AMS) and improves the sensitivity and efficiency for the detection of this isotope in artificial and environmental samples. In ILIAMS, a laser is overlapped with the ion beam during its passage through a radiofrequency quadrupole ion cooler. Those ions with electron affinity lower than the energy of the photons are selectively neutralized in a photodetachment process. Because the electron affinity of MgO is lower than that of AlO, ILIAMS can suppress the isobar ²⁶Mg by 14 orders of magnitude. No further isobar suppression on the high-energy side of the spectrometer is necessary, so that the more prolific AlO⁻ beam can now also be used at facilities with terminal voltages < 5 MV. At the 3 MV Vienna Environmental Research Accelerator (VERA) routine ²⁶Al AMS measurements assisted by ILIAMS are performed utilizing AlO⁻ extracted from the ion source and charge states 2+ and 3+ for the Al ions after the accelerator on the high-energy side of the spectrometer. The most efficient generation of AlO- currents (in the range of several mA) is realized when mixing the Al₂O₃ sample material with Fe powder. Blank materials are measured down to ²⁶Al/²⁷Al ratios of 5*10⁻¹⁶. The efficiency relative to the use of Al⁻ extraction is improved typically by a factor 3-5 and thus the new method is useful for measurements with highest sensitivity and down to very low ²⁶Al/²⁷Al ratios.

Permalink: https://www.hzdr.de/publications/Publ-32506
Publ.-Id: 32506


Investigation of an opposed-contact GaAs photoconductive semiconductor switch at 1-kHz excitation

Xu, M.; Dong, H.; Liu, C.; Wang, Y.; Hu, L.; Lan, C.; Luo, W.; Schneider, H.

The transient performance of gallium arsenide (GaAs) photoconductive semiconductor switches (PCSSs) triggered by laser diodes (LDs) at nano-joules (nJ) energy is of great significance for the potential high-power applications at high repetition rates. An opposed-contact GaAs PCSS with Ni/AuGe/WTi/Au electrodes is presented at single-shot and 1-kHz excitation. The influences of bias electric field up to 80 kV/cm on nonlinear characteristics are investigated quantitatively with a carriers' avalanche multiplication factor as high as 0.8 x 10⁴. The effect of electric field on the carriers' dynamic process and thermal accumulation in repetitive operation is analyzed. The transient electric field distribution is demonstrated by an ensemble Monte Carlo simulation.

Keywords: Avalanche multiplication; gallium arsenide GaAs; photoconductive semiconductor switch PCSS

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Permalink: https://www.hzdr.de/publications/Publ-32500
Publ.-Id: 32500


MR Image Changes of Normal-Appearing Brain Tissue after Radiotherapy

Witzmann, K.; Raschke, F.; Troost, E. G. C.

Radiotherapy is part of the standard treatment of most primary brain tumors. Large clinical target volumes and physical characteristics of photon beams inevitably lead to irradiation of surrounding normal brain tissue. This can cause radiation-induced brain injury. In particular, late brain injury, such as cognitive dysfunction, is often irreversible and progressive over time, resulting in a significant reduction in quality of life. Since 50% of patients have survival times greater than six months, radiation-induced side effects become more relevant and need to be balanced against radiation treatment given with curative intent. To develop adequate treatment and prevention strategies, the underlying cause of radiation-induced side-effects needs to be understood. This paper provides an overview of radiation-induced changes observed in normal-appearing brains measured with conventional and advanced MRI techniques and summarizes the current findings and conclusions. Brain atrophy was observed with anatomical MRI. Changes in tissue microstructure were seen on diffusion imaging. Vascular changes were examined with perfusion-weighted imaging and susceptibility-weighted imaging. MR spectroscopy revealed decreasing N-acetyl aspartate, indicating decreased neuronal health or neuronal loss. Based on these findings, multicenter prospective studies incorporating advanced MR techniques as well as neurocognitive function tests should be designed in order to gain more evidence on radiation-induced sequelae.

Keywords: radiotherapy; radiation-induced brain injuries; normal-appearing brain tissue; functional MRI; anatomical MRI; perfusion; diffusion; spectroscopy; atrophy

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Permalink: https://www.hzdr.de/publications/Publ-32499
Publ.-Id: 32499


Proton beam quality enhancement by spectral phase control of a PW-class laser system

Ziegler, T.; Albach, D.; Bernert, C.; Bock, S.; Brack, F.-E.; Cowan, T.; Dover, N. P.; Garten, M.; Gaus, L.; Gebhardt, R.; Goethel, I.; Helbig, U.; Irman, A.; Kiriyama, H.; Kluge, T.; Kon, A.; Kraft, S.; Kroll, F.; Löser, M.; Metzkes-Ng, J.; Nishiuchi, M.; Obst-Hübl, L.; Püschel, T.; Rehwald, M.; Schlenvoigt, H.-P.; Schramm, U.; Zeil, K.

We report on experimental investigations of proton acceleration from solid foils irradiated with PW‑class laser‑pulses, where highest proton cut‑off energies were achieved for temporal pulse parameters that varied significantly from those of an ideally Fourier transform limited (FTL) pulse. Controlled spectral phase modulation of the driver laser by means of an acousto‑optic programmable dispersive filter enabled us to manipulate the temporal shape of the last picoseconds around the main pulse and to study the effect on proton acceleration from thin foil targets. The results show that applying positive third order dispersion values to short pulses is favourable for proton acceleration and can lead to maximum energies of 70 MeV in target normal direction at 18 J laser energy for thin plastic foils, significantly enhancing the maximum energy compared to ideally compressed FTL pulses. The paper further proves the robustness and applicability of this enhancement effect for the use of different target materials and thicknesses as well as laser energy and temporal intensity contrast settings. We demonstrate that application relevant proton beam quality was reliably achieved over many months of operation with appropriate control of spectral phase and temporal contrast conditions using a state‑of‑the‑art high‑repetition rate PW laser system.

Related publications

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Permalink: https://www.hzdr.de/publications/Publ-32498
Publ.-Id: 32498


Dynamics of non-spherical particles at fluidic interface

Lecvrivain, G.

During this talk, I will report about my experimental and numerical results on the attachement of non-spherical particles on and off fluidic interfaces. The results apply to the field of mineral flotation, where hydrophobic particles are separated from water by rising gas bubbles.

  • Invited lecture (Conferences)
    Seminar at the Institute for Nano- and Microfluidics, Center of Smart, Interfaces, TU Darmstadt, 25.04.2019, Darmstadt, Germany

Permalink: https://www.hzdr.de/publications/Publ-32496
Publ.-Id: 32496


Data for: High-bias-field operation of GaAs photoconductive terahertz emitters

Welsch, M.; Singh, A.; Winnerl, S.; Pashkin, O.; Xu, M.; Li, M.; Helm, M.; Schneider, H.

Data file names start with the corresponding figure in the manuscript. For example- file "F1cd_velocity vs E_hs_Jan8.opju" means this data set is used to plot Fig. 1c and 1d (So, name start with F1cd_). 

Keywords: Terahertz emitter; Photoconductive; Terahertz

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-01
    DOI: 10.14278/rodare.907
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32492
Publ.-Id: 32492


Data for: Influence of Muscovite (001) Surface Nanotopography on Radionuclide Adsorption studied by kinetic Monte Carlo Simulations

Schabernack, J.; Kurganskaya, I.; Fischer, C.; Luttge, A.

Raw Data for the Publication: Influence of Muscovite (001) Surface Nanotopography on Europium Adsorption studied by kinetic Monte Carlo Simulations

Kinetic Monte Carlo (KMC) simulations were performed on the (001) muscovite face.
KMC simulations were divided in two parts: (1) surface dissolution (2) europium (Eu3+) adsorption to resulting surface

Simulation Settings:
    - Surface Size [unit cells]: 700 in a, 300 in b, 8 in c
    - Dissolved Atoms: 2,000,000
    - Adsorbed Atoms: 300,000

KMC Simulations:
    - Case(I)  [1PitDepth6]  : One single etch pit with a depth of 6 unit cells or ~12 nm / 10 Simulation Runs
    - Case(II) [6PitsDepth1] : Six inital etch pits with depths of 1 uni cell or ~2 nm / 10 Simulation Runs
    - Study of etch pit depth vs. number of octahedral surface atoms [OctahedralSitesDepth]: Six simulations with pit depths from 1 to 6 unit cells / 1 Simulation Run each

Produced Output Data from KMC Simulations. Each Run contains:
    - Number of Adsorbed Atoms and Time (Ad_Num.txt)
    - Number of Adsorbed Atoms by Position and Time (Ad_Site_Stat.txt)
    - Number of Dissolved Atoms and Time (diss_num_1.txt)
    - Number of Dissolved Atoms by Position and Time (site_stats_1.txt)
    - Four Files for Adsorption Visualization (Ad_mov_01 to _04.pdb)
    - Four Files for Dissolution Visualization (m_mov_001_1 to _4.pdb)

    .pdb files can be opened and viewed by using the Visual Molecular Dynamics (VMD) viewer (https://www.ks.uiuc.edu/Research/vmd/)
        Humphrey, W., Dalke, A. and Schulten, K., "VMD - Visual Molecular Dynamics", J. Molec. Graphics, 1996, vol. 14, pp. 33-38.

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-04-01
    DOI: 10.14278/rodare.911

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32491
Publ.-Id: 32491


Data for: Entrance effects in a radial Hele-Shaw cell: numerical and experimental study

Stergiou, G.; Eckert, K.; Schwarzenberger, K.

Hele-Shaw cells are a frequently used tool in various fields of chemical technology, and in environmental and biomedical engineering. The flow conditions near the inlet of a radial Hele-Shaw cell significantly affect the outcome of its technological applications. The present work combines Computational Fluid Dynamics (CFD) and micro-Particle Image Velocimetry (μPIV) to explain the entrance phenomena, i.e. flow detachment and vortex generation, in radial Hele-Shaw cells. The experiments show that the flow detachment is determined by the inlet flow Reynolds number, Re. Two-dimensional numerical simulations were employed to further investigate the role of the gap width, w to inlet diameter, D aspect ratio, w/D. The resulting flow regime map is divided by a transitional Re number, Ret, that depends on the aspect ratio. A further parametric study examining how Re and the aspect ratio affect the reattachment length yields an empirical correlation in power-law form. Finally, the impact of the inlet's geometrical features is briefly examined. The current work can be used as a design guide for future radial HS engineering applications.

Keywords: Hele-Shaw cell; flow separation; laminar flow; reattachment length; CFD; μPIV

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-31
    DOI: 10.14278/rodare.901

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32487
Publ.-Id: 32487


Status of LISEL@DREAMS

Forstner, O.; Weber, T.; Wendt, K.; Gadelshin, V.; Merchel, S.; Rugel, G.

Accelerator Mass Spectrometry (AMS) is a highly versatile tool to detect radionuclides on the ultra-trace level. LISEL@DREAMS aims for improving the AMS method by reducing the amount of stable isobars limiting its applicability especially in the mass region 50

Keywords: Accelerator Mass Spectrometry; Low-energy Isobar SEparation by Lasers; LISEL; AMS; radionuclide

  • Poster (Online presentation)
    Ion beam workshop 2021 - virtual meeting, 24.-25.03.2021, Online, World-wide

Permalink: https://www.hzdr.de/publications/Publ-32484
Publ.-Id: 32484


Influence of Muscovite (001) Surface Nanotopography on Radionuclide Adsorption Studied by Kinetic Monte Carlo Simulations

Schabernack, J.; Kurganskaya, I.; Fischer, C.; Luttge, A.

Mechanistic understanding and prediction of solute adsorption from fluids onto mineral surfaces is relevant for many natural and technical processes. Mineral surfaces in natural systems are often exposed to fluids at non-equilibrium conditions resulting in surface dissolution reactions. Such reactions cause the formation of surface nanotopography and, consequently, the exposure of different types of surface atoms. The quantitative effect of nanotopography on the efficiency of adsorption reactions at crystal surfaces is not known. Using kinetic Monte Carlo simulations, we combine a model of muscovite (001) face dissolution with a consequent model of europium adsorption on the rough mineral surface. The model considers three different adsorption sites based on the muscovite surface cations: silicon, tetrahedral and octahedral aluminum. Two different surface nanotopography configurations are investigated, both showing similar adsorption behavior. Octahedral aluminum surface atoms defined by having the highest reactivity towards adsorption are exposed solely on steps and pits on the muscovite (001) face. Thus, their availability directly depends on the surface nanotopography. The model results show the need for a more precise parameterization of surface site-specific adsorption, taking into account the coordination of the involved surface cation such as kink, step or terrace sites.

Keywords: kinetic Monte Carlo simulation; adsorption; dissolution; radionuclides; muscovite

Related publications

Permalink: https://www.hzdr.de/publications/Publ-32483
Publ.-Id: 32483


Teaching Machine Learning in 2020

Steinbach, P.; Seibold, H.; Guhr, O.

Faced by the abundant use of machine learning in industry and academia, the effective and efficient teaching of core concepts in this field becomes of high importance. For this, we organized a workshop on teaching methods in the field of machine learning. In this document, we summarize the current standing of the community as by our workshop and their methods. We touch on existing working concepts in machine learning didactics, what methods present initiatives use and cover open teaching resources available to date. With this, we hope to provide a starting point for future collaborations on this central topic given the expanding use of machine learning in science, industry and our daily lives.

Keywords: Machine Learning; Deep Learning; Data Science; Teaching; Didactics

  • Open Access Logo Contribution to proceedings
    Proceedings of the first Teaching Machine Learning and Artificial Intelligence Workshop at ECML-PKDD 2020, 14.09.2020, virtuell, virtuell
    Volume 141: European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases, http://proceedings.mlr.press/v141/

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Permalink: https://www.hzdr.de/publications/Publ-32481
Publ.-Id: 32481


Investigating the interplay of heat and mass transport in a three-layer liquid metal battery model

Klopper, T. S.

Thermal and solutal convection effects have been proven to have a significant impact in liquid metal batteries (LMBs) with potentially beneficial but eventually detrimental effects on their operation. LMBs are likely to be good candidates for solving the 21st century challenge of storing electrical energy on a large scale in order to ensure the stability of electrical grids in the future, which will consist of an increasing amount of renewable energies. With their fully liquid interior, they feature numerous phenomena of fluid dynamics, which are studied in order to adjust the battery’s design. Among them are convective phenomena, which play a role when density gradients form due to heating or compositional variations. The typical LMB consists of three segregated layers featuring different characteristics. Thermal convection typically occurs in the negative electrode and the electrolyte, while solutal convection is unique in the positive electrode, where it occurs during charge of the battery. Previous numerical studies observed that thermal convection is dominant either in the negative electrode or in the electrolyte, which depends strongly on the layers’ thicknesses. Coupling between the interfaces has been observed, but was not yet studied in-depth. Effects of solutal convection have been studied on the isolated positive electrode only and could be associated with substantial flow.
We performed numerical studies to examine the interfacial coupling of the two types of convection in a three-layer model. Therefore we made use of an OpenFOAM solver specifically developed for this problem. The solver was first validated by performing a grid independence study and comparing the results to previous solutions. A configuration was then studied, where significant flow evolves due to both thermal and solutal convection in all three regions. We observed chaotic flow patterns, which were strongly affected by the interfacial coupling. As a result, the flow phenomena in the electrolyte are highly irregular, as it is affected from the other layers both at its top and bottom interfaces. We suspect the behaviour to be highly dependent on the exact configuration of the battery and therefore suggest that these phenomena are studied more extensively in the future.

  • Master thesis
    Carl von Ossietzky Universität Oldenburg, 2021

Permalink: https://www.hzdr.de/publications/Publ-32480
Publ.-Id: 32480


Post-implantation defects in heavy ion implanted monocrystalline ZnO

Werner, Z.; Barlak, M.; Ratajczak, R.; Akhmadaliev, S.; Heller, R.; Staszkiewicz, B.; Zagórski, J.

Monocrystalline ZnO samples were implanted with Co (transition metal) and with Ar and Kr noble gas ions, with energies and doses leading to comparable damage in the host lattice as regards its extension and magnitude. Structural properties of the implantedZnOwere investigated by channeled Rutherford Backscattering Spectrometry (cRBS), aided with calculations using McChasy code. It was shown that the damage produced by implantation does not reach an amorphization level in all cases and is produced deeper in the crystal in comparison with theoretical predictions. The range and magnitude of damaged region are comparable in all cases of ion implantation.

Keywords: ZnO; heavy ion implantation; cRBS measurements; damage simulation

Permalink: https://www.hzdr.de/publications/Publ-32478
Publ.-Id: 32478


Oscillatory Copper Deposition on Conical Iron Electrodes in a Nonuniform Magnetic Field

Marinaro, G.; Huang, M.; Mutschke, G.; Yang, X.; Eckert, K.

We report the effect of a magnetic field on the deposition of copper ions on a conically shaped iron probe. In our setup, the magnetic forces and buoyancy are the key factors influencing the electrolyte flow and the mass transfer. Without external current, a spontaneous reduction of copper on the iron cone occurs, known as electroless deposition. Mach–Zehnder and differential interferometry indicate a variation in the concentration of copper ions near the cone. After an initial transient of about 60 s, temporal oscillations in the copper concentration are found under the effect of a magnetic field. In galvanostatic conditions, a similar oscillatory behavior of the concentration of the electrolyte is observed. Numerical simulations show that the oscillations are caused by the magnetic gradient, Lorentz force, and buoyancy force counteracting one an-other, and the oscillation frequency is estimated analytically based on this mechanism. Fur-thermore, we present a study on the oscillation frequency for both electroless and galvanostatic conditions with different current densities. The results of this study may stimulate future re-search aimed at the local control of the deposition rate and the realization of miniaturized, reg-ularly structured deposits using magnetic fields.

Keywords: Electrodeposition; magnetic field; mass transport; variation of ion concentration; Mach-Zehnder Interferometry

Permalink: https://www.hzdr.de/publications/Publ-32477
Publ.-Id: 32477


Numerical and experimental data set obtained from paraffin phantom measurements based on the capacitance wire-mesh sensor.

de Assis Dias, F.; Wiedemann, P.; Da Silva, M. J.; Schleicher, E.; Hampel, U.

This data set contains experimental and numerical data from a 12x12 wire-mesh sensor. A 12x12 WMS was used to measure paraffin phantoms created to mimic three flow patterns: slug, annular and bubble flow. The sensor was assembled with flanges and filled with tap water. Two models based on finite element model were used to generate the synthetic data. The first one is a basic FEM model, which was designed based on other models reported in the literature (i.e. the output signal is obtained by integrating the current density over the surface of a receiver wire). In the second model (FEM+EC), the electric potential is solved as the basic one, however, external circuits (macromodels) were coupled to the 3D geometry of the sensor to emulate the excitation and amplification systems of a real WMS.A mapping containing the coordinates and electrical properties of the paraffin phantoms was created through image processing and imported into the software COMSOL v.5.6. Thus, both basic FEM and FEM+EC models were used to generate synthetic data that can be direct compared to the experimental data.

Keywords: capacitance wire-mesh sensor; data set; phantom measurement; multiphase flow; finite element method

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-29
    DOI: 10.14278/rodare.897

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32476
Publ.-Id: 32476


Predicting the Risk of Metastases by PSMA-PET/CT—Evaluation of 335 Men with Treatment-Naïve Prostate Carcinoma.

Koerber, S.; Boesch, J.; Kratochwil, C.; Schlampp, I.; Ristau, J.; Winter, E.; Zschaebitz, S.; Hofer, L.; Herfarth, K.; Kopka, K.; Holland-Letz, T.; Jaeger, D.; Hohenfellner, M.; Haberkorn, U.; Debus, J.; Giesel, F.

Men diagnosed with aggressive prostate cancer are at high risk of local relapse or systemic
progression after definitive treatment. Treatment intensification is highly needed for that patient
cohort; however, no relevant stratification tool has been implemented into the clinical work routine
so far. Therefore, the aim of the current study was to analyze the role of initial PSMA-PET/CT as a prediction tool for metastases. In total, 335 men with biopsy-proven prostate carcinoma and PSMA-PET/CT for primary staging were enrolled in the present, retrospective study. The number
and site of metastases were analyzed and correlated with the maximum standardized uptake value (SUVmax) of the intraprostatic, malignant lesion. Receiver operating characteristic (ROC) curves were used to determine sensitivity and specificity and a model was created using multiple logistic regression. PSMA-PET/CT detected 171 metastases with PSMA-uptake in 82 patients. A statistically significant higher SUVmax was found for men with metastatic disease than for the cohort without distant metastases (median 16.1 vs. 11.2; p < 0.001). The area under the curve (AUC) in regard to predicting the presence of any metastases was 0.65. Choosing a cut-off value of 11.9 for SUVmax, a sensitivity and specificity (factor 1:1) of 76.0% and 58.4% was obtained. The current study confirms, that initial PSMA-PET/CT is able to detect a relatively high number of treatment-naïve men with metastatic prostate carcinoma. Intraprostatic SUVmax seems to be a promising parameter for the prediction of distant disease and could be used for treatment stratification—aspects which should be verified within prospective trials.

Keywords: prostate cancer; PSMA; PET; metastases; intraprostatic SUV

Permalink: https://www.hzdr.de/publications/Publ-32473
Publ.-Id: 32473


Chlorine doping of MoSe2 flakes by ion implantation

Prucnal, S.; Hashemi, A.; Ghorbani Asl, M.; Hübner, R.; Duan, J.; Wei, Y.; Sharma, D.; Zahn, D. R. T.; Ziegenrücker, R.; Kentsch, U.; Krasheninnikov, A.; Helm, M.; Zhou, S.

The efficient integration of transition metal dichalcogenides (TMDs) into the current electronic device technology requires mastering the techniques of effective tuning of their optoelectronic properties. Specifically, controllable doping is essential. For conventional bulk semiconductors, ion implantation is the most developed method offering stable and tunable doping. In this work, we demonstrate n-type doping in MoSe2 flakes realized by low-energy ion implantation of Cl+ ions followed by millisecond-range flash lamp annealing (FLA). We further show that FLA for 3 ms with a peak temperature of about 1000 °C is enough to recrystallize implanted MoSe2. The Cl distribution in few-layer-thick MoSe2 is measured by secondary ion mass spectrometry. An increase in the electron concentration with increasing Cl fluence is determined from the softening and red shift of the Raman-active A1g phonon mode due to the Fano effect. The electrical measurements confirm the n-type doping of Cl-implanted MoSe2. A comparison of the results of our density functional theory calculations and experimental temperature-dependent micro-Raman spectroscopy data indicates that Cl atoms are incorporated into the atomic network of MoSe2 as substitutional donor impurities.

Keywords: MoSe2; ion implantation; Flash Lamp Annealing; doping; 2D materials; DFT; Raman

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  • Secondary publication expected from 22.02.2022

Permalink: https://www.hzdr.de/publications/Publ-32472
Publ.-Id: 32472


Conductive hydrogels with dynamic reversible networks for biomedical applications

Xu, Y.; Patino Gaillez, M.; Rothe, R.; Hauser, S.; Voigt, D.; Pietzsch, J.; Zhang, Y.

Conductive hydrogels (CHs) are emerging as a promising and well-utilized platform for three-dimensional (3D) cell culture and tissue engineering to incorporate electron signals as biorelevant physical cues. In conventional covalently crosslinked conductive hydrogels, the network dynamics (e.g., stress relaxation, shear shining, and self-healing) required for complex cellular functions and many biomedical utilities (e.g., injection) cannot be easily realized. In contrast, dynamic conductive hydrogels (DCHs) are fabricated by dynamic and reversible crosslinks. By allowing for the breaking and reforming of the reversible linkages, DCHs can provide dynamic environments for cellular functions while maintaining matrix integrity. These dynamic materials can mimic some properties of native tissues, making them well suited for several biotechnological and medical applications. An overview of the design, synthesis, and engineering of DCHs is presented in this review, focusing on the different dynamic crosslinking mechanisms of DCHs and their biomedical applications.

Permalink: https://www.hzdr.de/publications/Publ-32469
Publ.-Id: 32469


LWFA PIConGPU setup for minimizing transverse phase space effects paper

Pausch, R.; Köhler, A.; Bastrakov, S.; Bussmann, M.; Couperus Cabadağ, J. P.; Irman, A.; Steiniger, K.; Widera, R.; Debus, A.

This repository contains the PIConGPU source code and setup files used for the "Minimizing transverse phase space effects on beam-loaded laser-wakefield accelerated electron beams" paper.

Keywords: PIConGPU; HPC; LWFA

  • Software in the HZDR data repository RODARE
    Publication date: 2021-03-23
    DOI: 10.14278/rodare.891
    License: GPL-3.0-only

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32465
Publ.-Id: 32465


Efficient and low-voltage vertical organic permeable base light-emitting transistors

Wu, Z.; Liu, Y.; Guo, E.; Darbandy, G.; Wang, S.-J.; Hübner, R.; Kloes, A.; Kleemann, H.; Leo, K.

Organic light-emitting transistors, three-terminal devices combining a thin-film transistor with a light-emitting diode, have generated increasing interest in organic electronics. However, increasing their efficiency while keeping the operating voltage low still remains a key challenge. Here, we demonstrate organic permeable base light-emitting transistors; these three-terminal vertical optoelectronic devices operate at driving voltages below 5.0 V; emit in the red, green and blue ranges; and reach, respectively, peak external quantum efficiencies of 19.6%, 24.6% and 11.8%, current efficiencies of 20.6 cd A–1, 90.1 cd A–1 and 27.1 cd A–1 and maximum luminance values of 9,833 cd m–2, 12,513 cd m–2 and 4,753 cd m–2. Our simulations demonstrate that the nano-pore permeable base electrode located at the centre of the device, which forms a distinctive optical microcavity and regulates charge carrier injection and transport, is the key to the good performance obtained. Our work paves the way towards efficient and low-voltage organic light-emitting transistors, useful for power-efficient active matrix displays and solid-state lighting.

Permalink: https://www.hzdr.de/publications/Publ-32463
Publ.-Id: 32463


Porosity characterisation of intact concrete specimens.

Roode-Gutzmer, Q. I.; Kulenkampff, J.; Barkleit, A.; Stumpf, T.

The chemical durability of concrete is largely dependent on the chemical reactivity of the silicate aggregates to alkaline pore water. Concrete irradiated at sufficient neutron fluences results in the breakdown of the Si-tetrahedron connected to 4 Si-atoms (Q⁴) to produce Q³ species, which is significantly more soluble in aqueous media. This leads to the alkali silica reaction (ASR), which is the most important degradation process in radiation-damaged concrete. For biological shielding concrete the occurrence of ASR has two ramifications: loss of mechanical strength (which shortens service life), and changes to the pore structure and reactive surface that play a role in the sorption characteristics and transport of radionuclides (neutron activated species or fission products from leaked reactor cooling water). Most investigations on the porosity of materials are conducted on pulverized specimens. We employ intact specimens. In order to achieve the highest possible resolution via μ-computed tomography (μ-CT), small cylindrical cores (0.15±0.01 g) were examined. The connected porosity of these specimens is examined using mercury intrusion porosimetry.

Keywords: concrete; intact specimens; porosity; mercury intrusion porosimetry; micro computed tomography

  • Open Access Logo Poster (Online presentation)
    3rd ICCCM International Conference on the Chemistry of Construction Materials, 15.-17.03.2021, Karlsruhe / Online, Germany

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Permalink: https://www.hzdr.de/publications/Publ-32460
Publ.-Id: 32460


Sub-diffractional cavity modes of terahertz hyperbolic phonon polaritons in tin oxide

Feres, F. H.; Mayer, R. A.; Wehmeier, L.; Maia, F. C. B.; Viana, E. R.; Malachias, A.; Bechtel, H. A.; Klopf, J. M.; Eng, L. M.; Kehr, S. C.; González, J. C.; Freitas, R. O.; Barcelos, I. D.

Hyperbolic phonon polaritons have recently attracted considerable attention in nanophotonics mostly due to their intrinsic strong electromagnetic field confinement, ultraslow polariton group velocities, and long lifetimes. Here we introduce tin oxide (SnO2) nanobelts as a photonic platform for the transport of surface and volume phonon polaritons in the mid- to far-infrared frequency range. This report brings a comprehensive description of the polaritonic properties of SnO2 as a nanometer-sized dielectric and also as an engineered material in the form of a waveguide. By combining accelerator-based IR-THz sources (synchrotron and free-electron laser) with s-SNOM, we employed nanoscale far-infrared hyperspectral-imaging to uncover a Fabry–Perot cavity mechanism in SnO2 nanobelts via direct detection of phonon-polariton standing waves. Our experimental findings are accurately supported by notable convergence between theory and numerical simulations. Thus, the SnO2 is confirmed as a natural hyperbolic material with unique photonic properties essential for future applications involving subdiffractional light traffic and detection in the farinfrared range.

Keywords: s-SNOM; near-field; THz; phonon polariton

Permalink: https://www.hzdr.de/publications/Publ-32459
Publ.-Id: 32459


Enhanced thermoelectric performance in Mg3+xSb1.5Bi0.49Te0.01 via engineering microstructure through melt-centrifugation

Ozen, M.; Yahyaoglu, M.; Candolfi, C.; Veremchuk, I.; Kaiser, F.; Burkhardt, U.; Snyder, G. J.; Grin, Y.; Aydemir, U.

N-type Zintl phases with earth-abundant and non-toxic constituent elements have attracted intense research interest thanks to their high thermoelectric efficiencies in the mid-temperature range, exemplified by the recently discovered Mg3Sb2 material. In this study, the liquid phase is expelled from the microstructure of the optimized n-type phase Mg3+xSb1.5Bi0.49Te0.01 by applying a melt-centrifugation technique leading to the formation of lattice dislocations, grain boundary dislocations and increasing porosity. Additional phonon scattering mechanisms were introduced in the microstructure through this manufacturing method, resulting in a significant 50% reduction in the total thermal conductivity from ∼1 W m−1 K−1 to ∼0.5 W m−1 K−1 at 723 K. Combined with high power factors, this reduced heat transport leads to a dimensionless thermoelectric figure of merit, zT, value of ∼1.64 at 723 K, 43% higher than the value obtained in untreated Mg3+xSb1.5Bi0.49Te0.01 (zT ∼ 1.14 at 723 K). This peak zT value yields a predicted device ZT of 0.95, and a promising theoretical thermoelectric efficiency of about 12%. These results further underline the great potential of the lightweight Mg3Sb2 material for mid-temperature energy harvesting via thermoelectric effects.

Permalink: https://www.hzdr.de/publications/Publ-32458
Publ.-Id: 32458


Effect of silver ion implantation on antibacterial ability of polyethylene food packing films

Lu, N.; Chen, Z.; Zhang, W.; Yang, G.; Liu, Q.; Böttger, R.; Zhou, S.; Liu, Y.

Bacterial adhesion on medical instruments’ and food packages’ surfaces causes implanted infections, food spoilage and human disease, therefore attracts a lot of attention in the field of medical and food applications. Containing the initial adhesion of bacteria on the surface of the material plays an important role in reducing potential safety hazards. In this work, we investigate the influence of silver ion implantation with different doses on the antibacterial performance of the polyethylene (PE) films. It is found out that silver ion implantation will not color the PE films but can improve their surface hydrophilicity. The silver-implanted PE films show the ability to inhibit bacterial adhesion and have the bactericidal effect, both of which can be improved with increasing silver implantation dose. This method also proves relatively safe, because the silver ions are relatively stable. The results will introduce potential applications for ion implantation in the food packing and food accessible materials.

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  • Secondary publication expected from 28.02.2022

Permalink: https://www.hzdr.de/publications/Publ-32456
Publ.-Id: 32456


Ekman boundary layers in a fluid filled precessing cylinder

Pizzi, F.; Giesecke, A.; Stefani, F.

The fluid flow in a precessing cylinder is investigated numerically with focus on the Ekman boundary layers in the strongly forced regime. Not surprisingly, in that regime, we find deviations from the linear theory due to significant modifications of the base flow in terms of an axisymmetric geostrophic mode whose rotation is opposite to that of the container. The transition of the bulk flow from a three-dimensional non-axisymmetric base flow to a geostrophic axisymmetric pattern is reflected in the scaling of both the sidewall boundary layers and the Ekman boundary layers on top and bottom of the cylinder. In our simulations, the Ekman layers surpass the threshold of the first instability (class A) and show an increase in the thickness together with a marked vertical flow advection inside the boundary layer in a limited range of the forcing magnitude. However, due to numerical restrictions in our simulations, which limit the range of achievable Ekman numbers, no developed boundary layer turbulence is found. An estimation by extrapolation shows that, for this purpose, Ekman numbers smaller by a factor of two have to be achieved.

Permalink: https://www.hzdr.de/publications/Publ-32453
Publ.-Id: 32453


Overview of the Rossendorf Data Repository (RODARE) at HZDR

Knodel, O.; Fiedler, M.; Gruber, T.

The lecture gives a short introduction of the Rossendorf Data Repository RODARE. Features are highlighted, the typical usage is demonstrated and best practices are provided.

Keywords: Rodare; Data Management

  • Invited lecture (Conferences) (Online presentation)
    RADIATE Data Management and Standards Workshop, 17.03.2021, Lisboa, Portugal

Permalink: https://www.hzdr.de/publications/Publ-32452
Publ.-Id: 32452


FFTF startup tests - joint publication raw data

Nikitin, E.

Models and results with DYN3D and Serpent (HZDR), and results of PARCS (PSI) and GenFoam (EPFL).

Keywords: SFR; DYN3D; PARCS; GeN-Foam; diffusion solver

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-17
    DOI: 10.14278/rodare.887

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32446
Publ.-Id: 32446


Neutronic Modelling of the FFTF Control Rod Worth Measurements with Diffusion Codes

Nikitin, E.; Fridman, E.; Mikityuk, K.; Radman, S.; Fiorina, C.

This paper presents an assessment of three deterministic core simulators with the focus on the neutronic performance in steady-state calculations of small Sodium cooled Fast Reactor cores. The selected codes are DYN3D, PARCS and the novel multi-physics solver GeN-Foam. By using these codes, the multi-group diffusion solutions are obtained for the selected twenty control rod worth measurements performed during the isothermal physics tests of the Fast Flux Test Facility (FFTF). The identical set of homogenized few-group cross sections applied in the calculations is generated with the Serpent Monte Carlo code. The numerical results are compared with each other as well as with the measured values. The obtained numerical results, such as the multiplication factors and control rod worth values, are in good agreement as compared to the experimental data. Furthermore, a comparison of the radial power distributions is presented between DYN3D, PARCS and GeN-Foam. Ultimately, the power distributions are compared to the full core Serpent solution, demonstrating an adequate performance of the selected deterministic tools. In overall, this study presents a verification and validation of the neutronic solvers applied by DYN3D, PARCS and GeN-Foam to steady-state calculations of SFR cores.

Keywords: SFR; DYN3D; PARCS; GeN-Foam; diffusion solver

Related publications

  • Contribution to proceedings
    Physics of Reactors PHYSOR 2020, 29.03.-02.04.2020, Cambridge, United Kingdom, 978-1-5272-6447-2
  • Open Access Logo European Physical Journal Web of Conferences 247(2021), 10017
    DOI: 10.1051/epjconf/202124710017

Permalink: https://www.hzdr.de/publications/Publ-32445
Publ.-Id: 32445


Identification and characterization of gallium-binding peptides

Schönberger, N.

The present work demonstrates how a peptide-based material can be obtained for the biosorptive recovery of metals from contaminated industrial wastewater. Starting with Phage surface display for the initial identification and optimization of gallium-binding peptides, all the following application-focussed experiments are based on chemically synthesized peptides.
Two chromatography-based biopanning methods for the identification of gallium-binding peptides from a commercial phage display library were developed. Five gallium-binding peptide sequences were identified and evaluated to show good gallium-binding properties.
Furthermore, the biosorption of free gallium and arsenic by gallium-binding bacteriophage clones was investigated. A large influence of the pH-value on the respective interactions was demonstrated.
Mutagenesis experiments were also carried out for a bacteriophage clone expressed peptide, in which a cysteine pair systematically replaced amino acids. Biosorption experiments with the resulting seven different bacteriophage mutants suggested a relationship between the rigidity of the peptide structure and the gallium-binding properties.
In isothermal titration experiments, the thermodynamics of the interaction between gallium and the peptides as chemically synthesized derivatives were characterized, independent of the bacteriophage. The peptides differed strongly in their interaction with gallium, and in some cases, the complex formation with gallium depended strongly on the surrounding buffer conditions.
The peptide with the amino acid sequence NYLPHQSSSPSR has particularly promising gallium-binding properties. Computer modeling suggests the probable structure of the peptide in aqueous solution and postulates a possible binding site for gallium.
The side-selective and covalent immobilization of the peptides on a polystyrene matrix led to the creation of a biocomposite for the biosorptive recovery of gallium. The sorption performance and desorbability of the peptide-based biosorption materials were determined in studies with model solutions and real waters from the semiconductor industry.

Keywords: Phage Surface Display; Gallium; Wastewater treatment; Peptides

  • Doctoral thesis
    TUBAF, 2021
    Mentor: Dr. Katrin Pollmann
    0112 Seiten

Permalink: https://www.hzdr.de/publications/Publ-32444
Publ.-Id: 32444


Influence of interstitial and substitutional atoms on magnetocaloric effects in RNi compounds

Chzhan, V. B.; Kurganskaya, A. A.; Tereshina, I. S.; Karpenkov, A. Y.; Ovchenkova, I. A.; Tereshina-Chitrova, E. A.; Andreev, A. V.; Gorbunov, D.; Lushnikov, S. A.; Verbetsky, V. N.

The effects of substitutional and interstitial atoms on the magnetic and magnetocaloric properties are investigated for RNi (R is rare earth) compounds attractive for magnetic solid-state cooling at cryogenic temperatures. We focused on combining weakly and highly anisotropic rare earth compounds and obtained GdxDy1-xNi (x = 0.1 and 0.9) compounds and their GdxDy1-xNiH3 hydrides. We observed a considerable decrease in Curie temperatures (TC) in the hydrides GdxDy1-xNiH3 compared to their parent alloys. The magnetocaloric effect (MCE) values of GdxDy1-xNiHy (y = 0 and 3) in the vicinity of TC were obtained and compared with literature data for the final GdNi and DyNi compounds. The maximum specific isothermal entropy changes –ΔsT at μ0ΔH = 5 T were 14.5, 17, and 17.5 J kg−1K−1 for GdNi, Gd0.9Dy0.1Ni, and Gd0.9Dy0.1NiH3, respectively. For DyNi, Gd0.1Dy0.9Ni, and Gd0.1Dy0.9NiH3, they were –ΔsT = 18, 15.5, and 12.5 J kg−1K−1 at μ0ΔH = 5 T, respectively. –ΔsT(H) in Gd0.9Dy0.1NiH3 at T = TC linearly increased in fields up to 7 T, while Gd0.1Dy0.9NiH3 at T ≥ TC showed a plateau-like magnetocaloric effect at μ0ΔH = 5 and 7 T. The observed effects were explained based on altered exchange and magnetocrystalline interactions in the modified compounds.

Permalink: https://www.hzdr.de/publications/Publ-32442
Publ.-Id: 32442


Compensating for artifacts in scanning near-field optical microscopy due to electrostatics

Nörenberg, T.; Wehmeier, L.; Lang, D.; Kehr, S. C.; Eng, L. M.

Nanotechnology and modern materials science demand reliable local probing techniques on the nanoscopic length scale. Most commonly, scanning probe microscopy methods are applied in numerous variants and shades, for probing the different sample properties. Scattering scanning near-field optical microscopy (s-SNOM), in particular, is sensitive to the local optical response of a sample, by scattering light off an atomic force microscopy (AFM) tip, yielding a wavelength-independent lateral resolution in the order of ∼10 nm. However, local electric potential variations on the sample surface may severely affect the probe-sample interaction, thereby introducing artifacts into both the optical near-field signal and the AFM topography. On the other hand, Kelvin-probe force microscopy (KPFM) is capable of both probing and compensating such local electric potentials by applying a combination of ac and dc-voltages to the AFM tip. Here, we propose to combine s-SNOM with KPFM in order to compensate for undesirable electrostatic interaction, enabling the in situ probing of local electric potentials along with pristine optical responses and topography of sample surfaces. We demonstrate the suitability of this method for different types of materials, namely, metals (Au), semiconductors (Si), dielectrics (SiO2), and ferroelectrics (BaTiO3), by exploring the influence of charges in the systems as well as the capability of KPFM to compensate for the resulting electric force interactions.

Permalink: https://www.hzdr.de/publications/Publ-32441
Publ.-Id: 32441


Broadband frequency filters with quantum dot chains

Ehrlich, T.; Schaller, G.

Two-terminal electronic transport systems with a rectangular transmission can violate standard thermodynamic uncertainty relations. This is possible beyond the linear response regime and for parameters that are not accessible with rate equations obeying detailed-balance. Looser bounds originating from fluctuation theorem symmetries alone remain respected. We demonstrate that optimal finite-sized quantum dot chains can implement rectangular transmission functions with high accuracy and discuss the resulting violations of standard thermodynamic uncertainty relations as well as heat engine performance.

Keywords: fluctuation theorems; thermodynamic uncertainty relation; Levitov-Lesovik formula; transmission; reaction-coordinate mapping

Permalink: https://www.hzdr.de/publications/Publ-32439
Publ.-Id: 32439


The Mu2e experiment at Fermilab

Müller, S.; Ferrari, A.; Knodel, O.; Rachamin, R.

Presentation in parallel session "Detector Systems (T19.1)" at 2021 spring meeting of German Physical Society (DPG), section "Particle Physics"

Keywords: Mu2e; DPG; Charged Lepton Flavor Violation

  • Lecture (Conference) (Online presentation)
    2021 spring meeting of German Physical Society (DPG), section "Particle Physics", 15.-19.03.2021, Dortmund (virtual), Germany

Permalink: https://www.hzdr.de/publications/Publ-32437
Publ.-Id: 32437


Demonstration of a laser-driven, narrow spectral bandwidth x-ray source for collective x-ray scattering experiments

Macdonald, M. J.; Saunders, A. M.; Bachmann, B.; Bethkenhagen, M.; Divol, L.; Doyle, M. D.; Fletcher, L. B.; Glenzer, S. H.; Kraus, D.; Landen, O. L.; Lefevre, H. J.; Klein, S. R.; Neumayer, P.; Redmer, R.; Schörner, M.; Whiting, N.; Falcone, R. W.; Döppner, T.

X-ray Thomson scattering (XRTS) is a powerful diagnostic technique that involves an x-ray source interacting with a dense plasma sample,
resulting in a spectrum of elastically and inelastically scattered x-rays. Depending on the plasma conditions, one can measure a range of
parameters from the resulting spectrum, including plasma temperature, electron density, and ionization state. To achieve sensitivity to collective
electron oscillations, XRTS measurements require limited momentum transfer where the spectral separation of elastic and inelastic scattering
is small. Such measurements require an x-ray probe source with a narrow bandwidth in order to reduce the spectral overlap between
scattering contributions, allowing for the different features to be more precisely deconvolved. In this investigation, we discuss the theory
behind how the bandwidth for a common XRTS probe, Zn He-a emission at 9 keV, can be reduced using a Cu K-edge filter. Proof-of-principle
experiments conducted at the OMEGA laser facility confirm that this is an effective method for attenuating the higher energy He-a peak in
the Zn emission spectrum. Calibration measurements at the National Ignition Facility show a reduction in spectral bandwidth from 87 eV to
48 eV when using the Cu filter, which will be important to improve the spectral resolution of future XRTS measurements that will probe plasmon
oscillations in strongly compressed plasmas of low-Z materials at densities of tens of g/cm3.

Permalink: https://www.hzdr.de/publications/Publ-32436
Publ.-Id: 32436


Implicit reduced Vlasov–Fokker–Planck–Maxwell model based on high-order mixed elements

Nikl, J.; Göthel, I.; Kuchařík, M.; Weber, S.; Bussmann, M.

etailed description of the transport processes in plasma is crucial for many disciplines. When the mean-free-path of the electrons is comparable or exceeds a characteristic length scale of the plasma profile, non-local behavior can be observed. Predictions of the diffusion theory are not valid and non-local electric and magnetic fields are generated. Kinetic modeling of these phenomena on time scales several orders of magnitude longer than the electron–electron collision time has proven to be cumbersome due to prohibitive requirements on the time step and violation of the conservation laws in the classical explicit Vlasov–Fokker–Planck methods. Therefore, a multi-dimensional conservative implicit Vlasov–Fokker–Planck–Maxwell method is proposed, where the distribution function is approximated by a truncated Cartesian tensor expansion. The electric and magnetic fields are modeled self-consistently, describing the generation process and emergence of non-locality in detail. Mixed finite elements are employed in space and the velocity dimension is discretized by staggered finite differences. Conservation properties are proved theoretically and the overall features are benchmarked on a series of physically representative problems. The second order convergence in velocity and the spatial order proportional to the polynomial order of the finite elements is shown. Further possible extensions of the method are discussed.

Keywords: plasma; simulation; vlasov; focker-planck; numerical methods; implicit; collisions

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  • Secondary publication expected from 01.06.2022

Permalink: https://www.hzdr.de/publications/Publ-32434
Publ.-Id: 32434


SPX Benchmark Part I: Results of Static neutronics -- HZDR results

Nikitin, E.; Fridman, E.

DYN3D and Serpent calculations (inputs and results) of the SPX Benchmark Part I: Results of Static neutronics.

Keywords: DYN3D; Serpent; Superphénix; Neutronics

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-15
    DOI: 10.14278/rodare.883

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Permalink: https://www.hzdr.de/publications/Publ-32433
Publ.-Id: 32433


ESFR-SMART WP1.2.2 dataset - DecayHeat

Fridman, E.

I/O for ESFR-SMART WP1.2.2  (DecayHeat)

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-15
    DOI: 10.14278/rodare.881

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Permalink: https://www.hzdr.de/publications/Publ-32432
Publ.-Id: 32432


Static Density Response of the Warm Dense Electron Gas beyond Linear Response Theory: Excitation of Harmonics

Böhme, M.; Dornheim, T.; Moldabekov, Z.; Vorberger, J.; Bonitz, M.

Experimental diagnostics as well as theoretical modeling of warm
dense matter (WDM) heavily rely on linear response theory.
However, Dornheim et. al. [Phys. Rev. Lett.125, 085001 (2020)]
showed that assuming the linear regime may not always be
justified in experiments studying WDM. In addition, the
intentional driving of non-linear effects should make new insight
into many-particle effects possible. We use ab initio Path-Integral
Monte-Carlo (PIMC) to obtain exact results for a harmonically
perturbed homogeneous electron gas. A thorough analysis for
different perturbation amplitudes is carried out. The
corresponding density response reveals resonances at the higher
harmonics of the perturbation wave vector. Analyzing the induced
density response as a function of the perturbation amplitude
shows the importance of the cubic response at the first harmonic
and of the quadratic response at the second harmonic.

Keywords: Warm Dense Matter; Path-Intergral Monte-Carlo

  • Poster (Online presentation)
    APS March Meeting, 15.-19.03.2021, Washington DC, USA

Permalink: https://www.hzdr.de/publications/Publ-32431
Publ.-Id: 32431


SPX-StartUp-ATHLET-StandAlone

Di Nora, V. A.

SPX StartUp tests: ATHLET-StandAlone models

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-15
    DOI: 10.14278/rodare.879

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Permalink: https://www.hzdr.de/publications/Publ-32430
Publ.-Id: 32430


Unser Rohstoffbedarf – Forschung für eine nachhaltige Rohstoffsuche in Europa im Spannungsfeld von Umwelt und Wirtschaft

Pospiech, S.

Vortrag für Schüler des Heidelberger Life-Science Labs (HLSL) am Deutschen Krebsforschungszentrum (DKFZ) im Rahmen der Freitagsvorträge, einer öffentlichen Vortragsreihe

Keywords: Schüler; Rohstoffe; Critical raw materials; Exploration; EU-Projekt

  • Lecture (others) (Online presentation)
    Freitagsvorträge des Heidelberger Life-Science Labs, 12.03.2021, Heidelberg, Germany

Permalink: https://www.hzdr.de/publications/Publ-32425
Publ.-Id: 32425


Robust Magnetoelectric Effect in Decorated Graphene/In2Se3 Heterostructure

Shang, J.; Tang, X.; Gu, Y.; Krasheninnikov, A.; Picozzi, S.; Chen, C.; Kou, L.

The magnetoelectric effect is a fundamental physical phenomenon that synergizes electric and magnetic degrees of freedom to generate distinct material responses like electrically tuned magnetism, which serves as a key foundation of the emerging field of spintronics. Here, we show by first-principles studies that ferroelectric (FE) polarization of an In2Se3 monolayer can modulate the magnetism of an adjacent transition-metal (TM)-decorated graphene layer via a ferroelectrically induced electronic transition. The TM nonbonding d-orbital shifts downward and hybridizes with carbon-p states near the Fermi level, suppressing the magnetic moment, under one FE polarization, but on reversed FE polarization this TM d-orbital moves upward, restoring the original magnetic moment. This finding of robust magnetoelectric effect in the TM-decorated graphene/In2Se3 heterostructure offers powerful insights and a promising avenue for experimental exploration of ferroelectrically controlled magnetism in two-dimensional (2D) materials.

Keywords: 2D materials; First-principles calculations

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  • Secondary publication expected from 05.01.2022

Permalink: https://www.hzdr.de/publications/Publ-32421
Publ.-Id: 32421


Formation of Highly Doped Nanostripes in 2D Transition Metal Dichalcogenides via a Dislocation Climb Mechanism

Lin, Y.; Karthikeyan, J.; Chang, Y.; Li, S.; Kretschmer, S.; Komsa, H.; Chiu, P.; Krasheninnikov, A.; Suenaga, K.

Doping of materials beyond the dopant solubility limit remains a challenge, especially when spatially nonuniform doping is required. In 2D materials with a high surface‐to‐volume ratio, such as transition metal dichalcogenides, various post‐synthesis approaches to doping have been demonstrated, but full control over spatial distribution of dopants remains a challenge. A post‐growth doping of single layers of WSe2 is performed by adding transition metal (TM) atoms in a two‐step process, which includes annealing followed by deposition of dopants together with Se or S. The Ti, V, Cr, and Fe impurities at W sites are identified by using transmission electron microscopy and electron energy loss spectroscopy. Remarkably, an extremely high density (6.4–15%) of various types of impurity atoms is achieved. The dopants are revealed to be largely confined within nanostripes embedded in the otherwise pristine WSe2. Density functional theory calculations show that the dislocations assist the incorporation of the dopant during their climb and give rise to stripes of TM dopant atoms. This work demonstrates a possible spatially controllable doping strategy to achieve the desired local electronic, magnetic, and optical properties in 2D materials.

Keywords: 2D materials; doping; first-principles simulations

Permalink: https://www.hzdr.de/publications/Publ-32420
Publ.-Id: 32420


Supporting data to the publication: Impact of surface charge on the motion of light-activated Janus micromotors

Baraban, Larysa

These video set (Video 1-5) summarizes the all experimental results. these videos were analyzed to get the dynamics of the Janus particle in the article further reflected in the figures.

Keywords: Janus particles; particle tracking

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-11
    DOI: 10.14278/rodare.877
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32418
Publ.-Id: 32418


Data (15/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

- Simulationsdaten für den ROFEX 1 zum Vergleich unterschiedlicher Detektorgrößen mit dem USRBIN-Kommando

Keywords: Electron beam; Beam position; FLUKA; ROFEX

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.873

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32417
Publ.-Id: 32417


Data (14/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

- Simulationsdaten für den ROFEX 1 zum Vergleich unterschiedlicher Detektorgrößen mit dem USRBIN-Kommando

Keywords: ROFEX; FLUKA; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.871

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32416
Publ.-Id: 32416


Data (13/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

- Simulationsdaten für den ROFEX 1 mit dem FLUKA-USRBDX-Kommando (Ro1_Pos_*)
- Simulationsdaten für den ROFEX 1 mit dem USRBIN-Kommando zum Vergleich unterschiedlicher Detektorgrößen

Keywords: ROFEX; Electron beam; FLUKA; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.869

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32415
Publ.-Id: 32415


Data (12/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

- Simulationsdaten für den ROFEX 1 mit dem USRBDX-FLUKA-Kommando

Keywords: ROFEX; FLUKA; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.867

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32414
Publ.-Id: 32414


Data (11/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

- Pos_* Simulationsdaten für den ROFEX 3 für verschiedene USRBINs mit EMFCUT=10keV
- Ro1_* Simulationsdaten für den ROFEX 1 mit EMFCUT = 100keV

Keywords: ROFEX; FLUKA; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.865

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32413
Publ.-Id: 32413


Data (10/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Untersuchung des Einflusses verschiedener USRBDX-Strukturen auf den Elektronenfluss.

Keywords: FLUKA; ROFEX; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.863

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32412
Publ.-Id: 32412


Data (9/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandtd, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Untersuchung des Einflusses verschiedener USRBDX-Strukturen auf den Elektronenfluss.

Keywords: ROFEX; FLUKA; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.861

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32411
Publ.-Id: 32411


Data (8/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Untersuchung des Einflusses verschiedener USRBDX-Strukturen auf den Elektronenfluss.

Keywords: ROFEX; FLUKA; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.859

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32410
Publ.-Id: 32410


Data (7/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Untersuchung des Einflusses verschiedener USRBDX-Strukturen auf den Elektronenfluss.

Keywords: ROFEX; FLUKA; Electron Beam

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.857

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32409
Publ.-Id: 32409


Data (6/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Untersuchung des Einflusses verschiedener USRBDX-Strukturen auf den Elektronenfluss.

Keywords: ROFEX; FLUKA; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.855

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32408
Publ.-Id: 32408


Data (5/15) for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Untersuchung des Einflusses verschiedener USRBDX-Strukturen auf den Elektronenfluss.

Keywords: ROFEX; FLUKA; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.849

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32407
Publ.-Id: 32407


Data for (4/15): Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Simulationsdaten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Untersuchung des Einflusses verschieder USRBDX-Strukturen auf den Elektronenfluss.

Keywords: ROFEX; FLUKA; Electron beam; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.851

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32406
Publ.-Id: 32406


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