Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

"Online First" included
Without submitted and only approved publications
Only approved publications

35200 Publications

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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  • Secondary publication expected

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


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

Downloads:

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

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


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

Downloads:

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


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

  • 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

Downloads:

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 (Online), 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

Downloads:

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, Katharina; Raschke, Felix; Troost, Esther 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 Europium 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.

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

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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

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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


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


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


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


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.

  • Journal of Materials Chemistry A (2021)

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


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

Downloads:

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

Downloads:

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

Downloads:

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

Downloads:

  • 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

Downloads:

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


Data (3/15) 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_17* enthält die Elektronenflusssimulationen für den ROFEX 3 mit EMFCUT=10keV

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.847

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32405
Publ.-Id: 32405


Data (2/15) 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

FLUKA-Daten für den ROFEX 3:
- Pos_18_* wurden zur Erstellung des Gleichungssystems Elektronenfluss(r, phi) verwendet.

Messdaten für den ROFEX 1:
-DC_4_2kHz* aufgenommen mit dem Präzisionsmessgerät LTT24

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.841

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32404
Publ.-Id: 32404


Data (1/15) 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

Daten für den ROFEX 3:
- Pos_17 bzw. Pos_19 wurden zur Bestimmung des Gleichungssystems Elektronenfluss(r, phi) verwendet
- groessenvgl diente dem Vergleich verschiedener USRBIN-Größen bei den ROFEX-3-Simulationen
- USRBIN70_Ro3 zeigte den Elektronenfluss an einer weiteren Detektorposition
- 66_21_Ro3 untersuchte einen leicht verschobenen USRBIN 66.

Daten für den ROFEX 1:
-Ro1_USRBIN_gekippt wurde für den Vergleich von USRBINs mit unterschiedlichen Winkeln verwendet

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.837

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32403
Publ.-Id: 32403


Scripts for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Skripte und FLUKA-Eingangsdateien ohne Strahlposition für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Keywords: FLUKA; ROFEX; Electron beam; Beam position

Related publications

  • Software in the HZDR data repository RODARE
    Publication date: 2021-03-08
    DOI: 10.14278/rodare.835

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-32402
Publ.-Id: 32402


Results for: Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Brandt, M.
Supervisor: Barthel, Frank

Auswertungen der Daten für die Masterarbeit Analysen zur Anwendbarkeit verschiedener Strahlbahn-Monitoring-Konzepte für die ultraschnelle Röntgencomputertomografie

Keywords: Electron beam; ROFEX; Beam position

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.845

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Permalink: https://www.hzdr.de/publications/Publ-32401
Publ.-Id: 32401


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

Brandt, Mira

Deutsch:
Die vorliegende Arbeit beschäftigt sich mit der Suche nach einem für die ultraschnelle Röntgencomputertomografie geeigneten Strahlbahn-Monitoring-Konzept. Mehrere Sekundäreffekte, die durch den Primärelektronenstrahl ausgelöst werden, wurden analysiert und aus ihnen die Rückstreuelektronenverteilung als Parameter für das Monitoring ausgewählt. Auf Grundlage von für verschiedene Strahlpositionen durchgeführten Simulationen des Elektronenflusses mit dem Monte-Carlo-Simulationspaket FLUKA wurden geeignet positionierte Kupferelektroden als Elektronendetektoren verwendet. Mit diesen Elektroden wurden Testmessungen durchgeführt. Die aufgenommenen Spannungskurven wurden mit den simulierten Elektronenflusskurven verglichen, wobei die Kurvenformen ähnlich waren. Das Spannungssignal wurde dagegen von den Simulationen unterschätzt. Da es während der ersten Messungen zu Spannungsüberschlägen kam, wurde ein zweites, verbessertes System entwickelt, das diese vermeiden soll.

English:
This thesis shows the search for a beam path monitoring concept suitable for ultrafast X-ray computed tomography. Several secondary effects triggered by the primary electron beam were analysed and from them the backscattered electron distribution was selected as a parameter to monitor the beam position. Based on simulations of the electron fluence, carried out for different beam positions with the Monte Carlo simulation package FLUKA, well positioned copper electrodes were used as electron detectors. Test measurements were done with these electrodes. The recorded voltage curves were compared with the simulated electron fluence curves which showed that the curve shapes are similar. However, the voltage signal was underestimated by the simulations. Because voltage flashovers occurred during the first measurements, a second improved system was developed to avoid them.

Keywords: Electron beam; Computed tomography; Beam position; Beam monitoring; ROFEX

Related publications

  • Master thesis
    TU Dresden, 2021
    Mentor: Dr.-Ing. Frank Barthel
    151 Seiten

Permalink: https://www.hzdr.de/publications/Publ-32400
Publ.-Id: 32400


Research data "Fluorination of graphene leads to susceptibility for nanopore formation by highly charged ion impact"

Creutzburg, S.; Hübner, R.; Facsko, S.

The depository contains STEM images, experimental data from charge exchange measurements and data from charge exchange simulations.

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-10
    DOI: 10.14278/rodare.843
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32397
Publ.-Id: 32397


Impact of surface charge on the motion of light-activated Janus micromotors

Huang, T.; Ibarlucea, B.; Caspari, A.; Synytska, A.; Cuniberti, G.; de Graaf, J.; Baraban, L.

Control over the motion of micromotors is of high relevance for lab-on-a-chip and biomedical engineering, wherein such particles encounter complex microenvironments. Here, we introduce an efficient way to influence the direction of motion and speed of Janus micromotors by modifying their surface properties and those of their immediate surroundings. We fabricated light-responsive Janus micromotors with positive and negative surface charge, both driven by ionic self-diffusiophoresis. These were used to observe direction-of-motion reversal in proximity to glass substrates for which we varied the surface charge. Quantitative analysis allowed us to extract the dependence of the particle velocity on the surface charge density at the substrate. This constitutes the first quantitative demonstration of the substrate’s surface charge on the motility of the light-activited diffusiophoretic motors in water. We provide qualitative understanding of these observations in terms of osmotic flow along the substrate generated through the ions released by the propulsion mechanism. Our results constitute a crucial step in moving toward practical application of self-phoretic artificial micromotors.

Related publications

Permalink: https://www.hzdr.de/publications/Publ-32393
Publ.-Id: 32393


PIConGPU setup: LPWFA downramp injection

Pausch, R.; Couperus Cabadag, J. P.; Bastrakov, S.; Bussmann, M.; Irman, A.; Kurz, T.; Schöbel, S.; Schramm, U.; Steiniger, K.; Ufer, P.; Widera, R.; Debus, A.

PIConGPU source code and setup files used for the LPWFA downramp injection simulation study

Keywords: PIConGPU; LWFA; PWFA; LPWFA; hybrid

  • Software in the HZDR data repository RODARE
    Publication date: 2021-03-09
    DOI: 10.14278/rodare.839
    License: GPL-3.0

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Permalink: https://www.hzdr.de/publications/Publ-32392
Publ.-Id: 32392


Reaction Pathways for Atomic Layer Deposition with Lithium Hexamethyl Disilazide, Trimethyl Phosphate, and Oxygen Plasma

Werbrouck, A.; Mattelaer, F.; Minjauw, M.; Nisula, M.; Julin, J. A.; Munnik, F.; Dendooven, J.; Detavernier, C.

Atomic layer deposition (ALD) of lithium-containing films is of interest for the development of next-generation energy storage devices. Lithium hexamethyl disilazide (LiHMDS) is an established precursor to grow these types of films. The LiHMDS molecule can either be used as a single-source precursor molecule for lithium or as a dual-source precursor molecule for lithium and silicon. Single-source behavior of LiHMDS is observed in the deposition process with trimethylphosphate (TMP) resulting in the deposition of crystalline lithium phosphate (Li3PO4). In contrast, LiHMDS exhibits dual-source behavior when combined with O-2 plasma, resulting in a lithium silicate. Both processes were characterized with in situ ellipsometry, in situ time-resolved full-range mass spectrometry, X-ray photoelectron spectroscopy (XPS), and elastic recoil detection analysis (ERDA). When we combined both reactants into a three-step LiHMDS-TMP-O-2* or LiHMDS-O-2*-TMP process, the dual-source nature of LiHMDS emerged again. By carefully combining our measurements, it is shown that film growth with LiHMDS (in combination with TMP and O-2 plasma) is driven by dipole-driven self-saturated surface interactions combined with dissociative chemisorption. We show that when hydroxyl groups are present on the surface, silicon will be incorporated in the films. These insights benefit the general understanding of the behavior of the LiHMDS and TMP precursors and may facilitate their effective use in ternary or quaternary processes.

Keywords: Reaction products; Adsorption; Precursors; Molecules; Plasma

Permalink: https://www.hzdr.de/publications/Publ-32388
Publ.-Id: 32388


Development and Validation of a GMP-Compliant High-Pressure Liquid Chromatography Method for the Determination of the Chemical and Radiochemical Purity of [18F]PSMA-1007, a PET Tracer for the Imaging of Prostate Cancer

Katzschmann, I.; Marx, H.; Kopka, K.; Hennrich, U.

For the PET imaging of prostate cancer, radiotracers targeting the prostate-specific membrane antigen (PSMA) are nowadays used in clinical practice. [18F]PSMA-1007, a radiopharmaceutical labeled with fluorine-18, has excellent properties for the detection of prostate cancer. Essential for the human use of a radiotracer is its production and quality control under GMP-compliance. For this purpose, all analytical methods have to be validated. [18F]PSMA-1007 is easily radiosynthesized in a one-step procedure and isolated using solid phase extraction (SPE) cartridges followed by formulation of a buffered injection solution and for the determination of its chemical and radiochemical purity a robust, fast and reliable quality control method using radio-HPLC is necessary. After development and optimizations overcoming problems in reproducibility, the here described radio-HPLC method fulfills all acceptance criteria-for e.g., specificity, linearity, and accuracy-and is therefore well suited for the routine quality control of [18F]PSMA-1007 before release of the radiopharmaceutical. Recently a European Pharmacopeia monograph for [18F]PSMA-1007 was published suggesting a different radio-HPLC method for the determination of its chemical and radiochemical purity. Since the here described method has certain advantages, not least of all easier technical implementation, it can be an attractive alternative to the monograph method. The here described method was successfully validated on several radio-HPLC systems in our lab and used for the analysis of more than 60 batches of [18F]PSMA-1007. Using this method, the chemical and radiochemical purity of [18F]PSMA-1007 can routinely be evaluated assuring patient safety.

Keywords: GMP; PSMA; [18F]PSMA-1007; high performance liquid chromatography (HPLC); positron emission tomography (PET); prostate cancer; validation

Permalink: https://www.hzdr.de/publications/Publ-32386
Publ.-Id: 32386


Synthesis and application of a thiol-reactive HBED-type chelator for development of easy-toproduce Ga-radiopharmaceutical kits and imaging probes

Klika, K.; Da, P. C.; Kopka, K.; Smith, G.; Makarem, A.

In radiopharmaceutical syntheses, maleimide is commonly used for linking thiol-bearing bioactive molecules to metal-complexing ligands (chelators). However, due to instability of the resulting linkage, phenyloxadiazolyl methylsulfone (PODS) was developed as an alternative to maleimide. This coupling strategy has never been attempted with HBED which is a powerful chelator for gallium-radiolabeling especially at ambient temperature. Here we present HBED-CC-PODS as a bifunctional chelator scaffold for the site-selective conjugation of thiol-bearing vectors and [68Ga]Ga-radiolabeling.

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  • Secondary publication expected from 04.03.2022

Permalink: https://www.hzdr.de/publications/Publ-32385
Publ.-Id: 32385


Radiation Studies for Mu2e and Mu2e-II - brief status report

Müller, S.

Presentation at "MU2E-II workshop" (virtuell)

  • Open Access Logo Lecture (Conference) (Online presentation)
    Mu2e-II Snowmass22 Workshop, 03.03.2021, Chicago (virtual), USA

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Permalink: https://www.hzdr.de/publications/Publ-32375
Publ.-Id: 32375


Highlight selection of radiochemistry and radiopharmacy developments by editorial board

Aime, S.; Al-Qahtani, M.; Behe, M.; Bormans, G.; Carlucci, G.; Dasilva, J.; Decristoforo, C.; Duatti, A.; Elsinga, P.; Kopka, K.; Li, X.; Liu, Z.; Mach, R.; Middel, O.; Passchier, J.; Patt, M.; Penuelas, I.; Rey, A.; Scott, P.; Todde, S.; Toyohara, J.; Vugts, D.; Yang, Z.

Background: The Editorial Board of EJNMMI Radiopharmacy and Chemistry releases a biyearly highlight commentary to update the readership on trends in the field of radiopharmaceutical development.
Results: This commentary of highlights has resulted in 23 different topics selected by each member of the Editorial Board addressing a variety of aspects ranging from novel radiochemistry to first in man application of novel radiopharmaceuticals.
Conclusion: Trends in radiochemistry and radiopharmacy are highlighted demonstrating the progress in the research field being the scope of EJNMMI Radiopharmacy and Chemistry.

Permalink: https://www.hzdr.de/publications/Publ-32374
Publ.-Id: 32374


Field-induced valence fluctuations in YbB12

Kurihara, R.; Miyake, A.; Tokunaga, M.; Ikeda, A.; Matsuda, Y. H.; Miyata, A.; Gorbunov, D.; Nomura, T.; Zherlitsyn, S.; Wosnitza, J.

We performed high-magnetic-field ultrasonic experiments on YbB12 up to 59 T to investigate the valence fluctuations in Yb ions. In zero field, the longitudinal elastic constant C11, the transverse elastic constants C44 and (C11 −C12)/2, and the bulk modulus CB show a hardening with a change of curvature at around 35 K indicating a small contribution of valence fluctuations to the elastic constants. When high magnetic fields are applied at low temperatures, CB exhibits a softening above a field-induced insulator-metal transition signaling field-induced valence fluctuations. Furthermore, at elevated temperatures, the field-induced softening of CB takes place at even lower fields and CB decreases continuously with field. Our analysis using the multipole susceptibility based on a two-band model reveals that the softening of CB originates from the enhancement of multipole-strain interaction in addition to the decrease of the insulator energy gap. This analysis indicates that field-induced valence fluctuations of Yb cause the instability of the bulk modulus CB.

Permalink: https://www.hzdr.de/publications/Publ-32373
Publ.-Id: 32373


SC-XRD data of U13 cluster

Fichter, S.; Radoske, T.; Ikeda-Ohno, A.

Collected frames of SC-XRD measurement of crystal consisting of U13 cluster. Refined cif file is also included.

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-04
    DOI: 10.14278/rodare.829

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Permalink: https://www.hzdr.de/publications/Publ-32371
Publ.-Id: 32371


Towards Targeted Alpha Therapy with Actinium 225: Chelators for Mild Condition Radiolabeling and Targeting PSMA – a Proof of Concept Study

Reissig, F.; Bauer, D.; Zarschler, K.; Novy, Z.; Bendova, K.; Kopka, K.; Pietzsch, H.-J.; Petrik, M.; Mamat, C.

Currently, targeted alpha therapy is one of the most investigated topics in radiopharmaceutical cancer management. Especially, the alpha emitter 225 Ac provides excellent nuclear properties and is gaining increasing popularity for the treatment of various tumor entities. We herein report on the synthesis of two universal 225Ac-chelators for mild condition radiolabeling and binding sites to conjugate biomolecules via the copper-mediated click chemistry. A convenient radiolabeling procedure was investigated as well as the complex stability proved for both chelators and two PSMA-targeting model radioconjugates. Studies regarding affinity and cell survival were per-formed on LNCaP cells followed by biodistribution studies, which were performed using LNCaP tumor-bearing mice. High efficiency radiolabeling for all conjugates was demonstrated. Cell binding studies revealed a fourfold lower cell affinity for the PSMA conjugate with one targeting vector compared to the conjugate owing two targeting vectors. Additionally, these differences were verified by in vitro cell survival evaluation and biodistribution studies, both showing a higher therapeutic efficiency for the same dose on a cellular leve, a higher tumor up-take (15%ID/g) and a rapid whole body clearance after 24 hours. The synthesized chelators will overcome obstacles of lacking stability and worse labeling needs regarding 225Ac complexation using the DOTA chelator. Moreover, the universal functionalization expands the coverage of these chelators in combination with any sensitive bio(macro)molecule, thus improving treat-ment of any addressable tumor target.

Keywords: Targeted Alpha Therapy; click labeling; Actinium-225; PSMA; Biodistribution

Permalink: https://www.hzdr.de/publications/Publ-32369
Publ.-Id: 32369


Characterization of the LUNA neutron detector array for the measurement of the 13C(alpha,n)16O reaction

Csedreki, L.; Ciani, G. F.; Balibrea-Correa, J.; Best, A.; Aliotta, M.; Barile, F.; Bemmerer, D.; Boeltzig, A.; Broggini, C.; Bruno, C. G.; Caciolli, A.; Cavanna, F.; Chillery, T.; Colombetti, P.; Corvisiero, P.; Davinson, T.; Depalo, R.; Di Leva, A.; Elekes, Z.; Ferraro, F.; Fiore, E. M.; Formicola, A.; Fülöp, Z.; Gervino, G.; Guglielmetti, A.; Gustavino, C.; Gyürky, G.; Imbriani, G.; Janas, Z.; Junker, M.; Kochanek, I.; Lugaro, M.; Marigo, P.; Masha, E.; Mazzocchi, C.; Menegazzo, R.; Mossa, V.; Pantaleo, F. R.; Paticchio, V.; Perrino, R.; Piatti, D.; Prati, P.; Schiavulli, L.; Stöckel, K.; Straniero, O.; Szücs, T.; Takács, M. P.; Terrasi, F.; Zavatarelli, S.

We introduce the LUNA neutron detector array developed for the investigation of the 13C(𝛼, 𝑛)16O reaction towards its astrophysical 𝑠-process Gamow peak in the low-background environment of the Laboratori Nazionali del Gran Sasso (LNGS). Eighteen 3He counters are arranged in two different configurations (in a vertical and a horizontal orientation) to optimize neutron detection efficiency, target handling and target cooling over the investigated energy range E𝛼,lab = 300 − 400 keV (En = 2.2 − 2.6 MeV in emitted neutron energy). As a result of the deep underground location, the passive shielding of the setup and active background suppression using pulse shape discrimination, we reached a total background rate of 1.23 ± 0.12 counts/hour. This resulted in an improvement of two orders of magnitude over the state of the art allowing a direct measurement of the 13C(𝛼, 𝑛)16O cross-section down to E𝛼,lab = 300 keV. The absolute neutron detection efficiency of the setup was determined using the 51V(p,n)51Cr reaction and an AmBe radioactive source, and completed with a Geant4 simulation. We determined a (34 ± 3)% and (38 ± 3)% detection efficiency for the vertical and horizontal configurations, respectively, for En = 2.4 MeV neutrons.

Permalink: https://www.hzdr.de/publications/Publ-32368
Publ.-Id: 32368


SERPENT2-SUBCHANFLOW-TRANSURANUS pin-by-pin depletion calculations for a PWR fuel assembly

Garcia, M.; Tuominen, R.; Gommlich, A.; Ferraro, D.; Valtavirta, V.; Imke, U.; van Uffelen, P.; Mercatali, L.; Sanchez-Espinoza, V.; Leppänen, J.; Kliem, S.

This work presents the results for a coupled neutronic-thermalhydraulic-thermomechanic pin-level depletion calculation of a PWR fuel assembly using Serpent2-SUBCHANFLOWTRANSURANUS. This tool is based on a semi-implicit depletion scheme with pin-by-pin feedback, mesh-based field exchange and an object-oriented software design. The impact of including fuel-performance capabilities is analyzed, with focus on high-burnup effects. The treatment of the Doppler feedback to the neutronics is examined as well, in particular the use of radial fuel-temperature profiles or radially averaged values.

Keywords: SERPENT2; SUBCHANFLOW; TRANSURANUS; Multiphysics; PWR

Permalink: https://www.hzdr.de/publications/Publ-32367
Publ.-Id: 32367


Data for: Experimental studies on bubble aspect ratio and corresponding correlations under bubble swarm condition

Liu, L.; Zhang, H.; Yan, H.; Ziegenhein, T.; Heßenkemper, H.; Zhou, P.; Lucas, D.

Zip-file that contains the raw images on a study on bubble aspect ratio under swarm condition. Further information can be found in the respective paper.

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-02
    DOI: 10.14278/rodare.827
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32366
Publ.-Id: 32366


Data for: Bremsstrahlung emission and plasma characterization driven by moderately relativistic laser–plasma interactions

Singh, S.; Armstrong, C. D.; Kang, N.; Ren, L.; Liu, H.; Hua, N.; Rusby, D. R.; Klimo, O.; Versaci, R.; Zhang, Y.; Sun, M.; Zhu, B.; Lei, A.; Ouyang, X.; Lancia, L.; Laso Garcia, A.; Wagner, A.; Cowan, T. E.; Zhu, J.; Schlegel, T.; Weber, S.; McKenna, P.; Neely, D.; Tikhonchuk, V.; Kumar, D.

Relativistic electrons generated by the interaction of petawatt-class short laser pulses with solid targets can be used to generate bright x-rays via bremsstrahlung. The efficiency of laser energy transfer into these electrons depends on multiple parameters including the focused intensity and pre-plasma level. This paper reports experimental results from the interaction of a high intensity petawatt-class glass laser pulses with solid targets at a maximum intensity of 1019 W cm−2. In-situ measurements of specularly reflected light are used to provide an upper bound of laser absorption and to characterize focused laser intensity, the pre-plasma level and the generation mechanism of second harmonic light. The measured spectrum of electrons and bremsstrahlung radiation provide information about the efficiency of laser energy transfer.

Keywords: Plasma physics; Bremsstrahlung; Laser-plasma

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-01-06
    DOI: 10.14278/rodare.825
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32365
Publ.-Id: 32365


HZDR Multiphase Case Collection for OpenFOAM

Hänsch, S.; Draw, M.; Evdokimov, I.; Khan, H.; Krull, B.; Lehnigk, R.; Liao, Y.; Lyu, H.; Meller, R.; Schlegel, F.; Tekavčič, M.
Other: Couteau, Arthur; Other: Upadhyay, Kartik; Other: Mohite, Onkar; Other: Kriebitzsch, Sebastian

HZDR Multiphase Case Collection for OpenFOAM contains simulation setups for the open-source CFD software OpenFOAM with the HZDR multiphase addon. The simulation setups are separated into polydisperse bubbly flows utilising the HZDR Baseline model set according to Liao et al. (Chem Eng Sci, 2019, Vol. 202, 55-69) and setups for a hybrid modelling approach (disperse and resolved interfaces) according to Meller et al. (Int J Numer Meth Fluids, 2021, Vol. 93, 748–773).

Cases using the HZDR Baseline model set

baseline/1998_Liu

baseline/2005_Lucas_et_al

baseline/2008_Shawkat

baseline/2009_Hosokawa

baseline/2013_Hosokawa_and_Tomiyama

baseline/2016_Kim_et_al

Cases using the hybrid modelling approach

hybrid/wenka/2D-MP3-23

hybrid/risingBubbleHysingEtAl2009

hybrid/risingBubbleBalcazarEtAl2015

hybrid/risingBubbleMellerEtAl2021

  • Reference for case setup: Meller et al., Flow Turbul Combust (submitted)

Keywords: Multiphase Flow; Numerical Simulations; OpenFOAM; CFD; Baseline model; Multi-field two-fluid model; Eulerian-Eulerian model; Free Surface

  • Software in the HZDR data repository RODARE
    Publication date: 2021-02-15
    DOI: 10.14278/rodare.811
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-32364
Publ.-Id: 32364


Control Over Self-Assembled Janus Clusters by the Strength of Magnetic Field in H₂O₂

Alsaadawi, Y.; Eichler-Volf, A.; Heigl, M.; Zahn, P.; Albrecht, M.; Erbe, A.

Microscope video of capped Janus particles propelled in Hydrogen peroxide under influence of varying magnetic fields. The caps compose of ferromagnetic (Co) and paramagnetic (Pd, H2O2 catalyst) elements carefully deposited onto one hemisphere of silica particles, which will later exhibit aligned magnetic moments upon saturation in 1 T magnetic field. The videos demonstrate different motion profiles depending on cluster shapes, with the later determined by cap-cap interaction of individual particles. 

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-03-01
    DOI: 10.14278/rodare.823

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Permalink: https://www.hzdr.de/publications/Publ-32363
Publ.-Id: 32363


Experimental studies on bubble aspect ratio and corresponding correlations under bubble swarm condition

Liu, L.; Zhang, H.; Yan, H.; Ziegenhein, T.; Heßenkemper, H.; Zhou, P.; Lucas, D.

The bubble shape affects the gas-liquid interface momentum, heat and mass transfer, as well as the flow field around the bubble. Correctly predicting the bubble shape is challenging but indispensable under bubble swarm conditions. In this work, the bubble aspect ratio, which is adopted for the characterization of the bubble shape, is obtained through high-speed photography combined with an image processing algorithm from several experiments with an oscillating bubble plume. The results show that the bubble aspect ratio tends to be a constant value with increasing the bubble diameter, rather than decreasing as predicted by various empirical correlations developed in single bubble experiments. None of the available empirical correlations can accurately correlate the bubble aspect ratio with Weber number or Tadaki number. Among the available correlations in literature, Eo based correlation proposed by Besagni and Inzoli (2016) and Eo-Re based correlation proposed by Besagni and Deen (2019) show a better performance. The predicted values of Eo-Re based correlation developed in this work are the closest to the experimental data compared with others.

Keywords: bubble shape; bubble aspect ratio; bubble swarm; dimensionless number; emperical correlation

Related publications

Permalink: https://www.hzdr.de/publications/Publ-32354
Publ.-Id: 32354


ASTRID-DYN3D

Fridman, Emil

ASTRID-DYN3D: XS generation and full core simulations

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-02-25
    DOI: 10.14278/rodare.821

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Permalink: https://www.hzdr.de/publications/Publ-32353
Publ.-Id: 32353


Spatially resolved Eu(III) environments by chemical microscopy

Drobot, B.

Archiv of research data for the manuscript

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-02-24
    DOI: 10.14278/rodare.819

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Permalink: https://www.hzdr.de/publications/Publ-32350
Publ.-Id: 32350


Microfocus X-ray Computed Tomography of a Plastic Toy ("HIPPO"): Projection Data

Boden, S.

Raw and preprocessed projection data from a microfocus X-ray CT of a plastic toy ("HIPPO"). To be used as demo dataset for the PARIS reconstruction framework.

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2021-02-23
    DOI: 10.14278/rodare.817

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Permalink: https://www.hzdr.de/publications/Publ-32348
Publ.-Id: 32348


Cytoplasmic localization of prostate-specific membrane antigen inhibitors may confer advantages for targeted cancer therapies.

Matthias, J.; Engelhardt, J.; Schäfer, M.; Bauder-Wüst, U.; Meyer, P.; Haberkorn, U.; Eder, M.; Kopka, K.; Hell, S.; Eder, A.

Targeted imaging and therapy approaches based on novel prostate-specific membrane antigen (PSMA) inhibitors have fundamentally changed the treatment regimen of prostate cancer. However, the exact mechanism of PSMA inhibitor internalization has not yet been studied, and the inhibitors' subcellular fate remains elusive. Here we investigated the intracellular distribution of peptidomimetic PSMA inhibitors and of PSMA itself by stimulated emission depletion (STED) nanoscopy, applying a novel non-standard live cell staining protocol. Imaging analysis confirmed PSMA cluster formation at the cell surface of prostate cancer cells and clathrin-dependent endocytosis of PSMA inhibitors. Following the endosomal pathway, PSMA inhibitors accumulated in prostate cancer cells at clinically relevant time points. In contrast to PSMA itself, PSMA inhibitors were found to eventually distribute homogeneously in the cytoplasm, a molecular condition that promises benefits for treatment as cytoplasmic and in particular perinuclear enrichment of the radionuclide carriers may better facilitate the radiation-mediated damage of cancerous cells. This study is the first to reveal the subcellular fate of PSMA/PSMA inhibitor complexes at the nanoscale and aims to inspire the development of new approaches in the field of prostate cancer research, diagnostics, and therapeutics.

Keywords: Prostate Cancer; Prostate-Specific Membrane Antigen; Dual-Labeled PSMA Inhibitors; Stimulated Emission Depletion Nanoscopy; Theranostics

Permalink: https://www.hzdr.de/publications/Publ-32347
Publ.-Id: 32347


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