Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

The actinide-containing mineral monazite–(Ce) is a common accessory rock component that bears petrogenetic information, is widely used in geochronology and thermochronology, and is considered as potential host material for immobilisation of radioactive waste. Natural samples of this mineral show merely moderate degrees of radiation damage, despite having sustained high self-irradiation induced by the decay of Th and U (for the sample studied herein 8.9 ± 0.3 × 10¹⁹ α/g). This is assigned to low damage-annealing temperature of monazite–(Ce) and “alpha-particle-assisted reconstitution”.
Here we show that the response of monazite–(Ce) to alpha radiation changes dramatically, depending on the damage state. Only in radiation-damaged monazite–(Ce), ⁴He ions cause gradual structural restoration. In contrast, its high-temperature annealed (i.e. well crystalline) analogue and synthetic CePO₄ experience He-irradiation damage. Alpha-assisted annealing contributes to preventing irradiation-induced amorphisation (“metamictisation”) of monazite–(Ce); however, this process is only significant above a certain damage level.

Detailed derivation of the analytical, reciprocal-space approach of Hessian calculation within the self- consistent-charge density functional based tight-binding framework (SCC-DFTB) is presented. This ap- proach provides an accurate and efficient way for obtaining the SCC-DFTB Hessian of periodic systems. Its superiority with respect to the traditional numerical force differentiation method is demonstrated for doped graphene, graphene nanoribbons, boron-nitride nanotubes, bulk zinc-oxide and other systems.

Zur Zeit werden in Deutschland noch 6 Kernkraftwerke zur Stromerzeugung betrieben. Bis 2022 soll das letzte Kernkraftwerk abgeschaltet werden – Deutschlands Ausstieg aus der Atomkraft. Der Atomausstieg ist ein wichtiger Schritt für die Energiewende mit dem Ziel einer langfristigen und vollständigen Umstellung auf erneuerbare Energien wie z. B. Wasserkraft, Sonnen- und Windenergie.
Der Ausstieg aus der Kernenergie bringt auch einige Konsequenzen mit sich, für welche wir die Verantwortung übernehmen müssen. Eine der größten Herausforderungen ist dabei die sichere und langfristige Lagerung des Atommülls. Weltweit hat sich hierbei das Konzept einer tiefen-geologischen Lagerung – etwa 500 m bis 1000 m unter der Erde – durchgesetzt. Die unterschiedlichen Materialien und Gesteine werden momentan auf ihre Eignung für das Endlager in Deutschland untersucht. Viele verschiedene Fachdisziplinen sind dafür relevant: Geologie, Mineralogie, (Radio-)Chemie, Physik, Mathematik, Materialwissenschaften, Architektur – um hier nur einige zu nennen.
Interessanterweise spielt auch die Biologie bei der Planung des Endlagers eine Rolle. Lebewesen können auf verschiedene Art und Weise mit den hier verwendeten Materialien – sogar mit dem Atommüll selbst – interagieren. Zu den hauptsächlich hier betrachteten Lebewesen zählen Pflanzen, Pilze und Mikroorganismen (Bakterien, Archaeen, einzellige Eukaryota). Bedingt durch ihren Stoffwechsel sind Mikroorganismen in der Lage, Materialien und deren Eigenschaften zu verändern. Da die Lagerung des Atommülls sicher und langfristig sein muss, ist es wichtig zu erforschen, inwiefern Mikroorganismen die verwendeten Materialien verändern und deren Eigenschaften möglicherweis beeinflussen.

Der Vortrag gibt einen Einblick in die faszinierende Welt der Mikroorganismen und zeigt zugleich deren Relevanz für die sichere und langfristige Lagerung des Atommülls.

Au-silica core-shell nanoparticles have been irradiated with 20 keV He+ ions up to a maximum fluence of 4.7x10(17) ions/cm(2). The nanoscale structural and crystallographic evolution induced by He+ ion irradiation was followed at various stages using Transmission Electron Microscopy (TEM). During irradiation satellite Au clusters are formed around the main Au core, which remained crystalline even after the maximum He+ ion fluence. The spherical silica shell deformed into a hemisphere due to He+ ion irradiation. Three dimensional Monte-Carlo simulations, based on the binary collision approximation, have been performed on stacked infinite layers and an individual particle. The stacked layers results show that the He+ beam interacts with most of the nanoparticle and Au migrates in the direction of beam incidence agreeing with experimental findings. The individual particle results match the experiment in terms of the volume which is sputtered away however additional mechanisms, not included in the simulations, are present in the experiment during the satellite formation and silica shell deformation. These results show the ability for 20 keV He+ ions to be used for the modification of nanostructures. Furthermore, these results contribute to a quantitative understanding of the dynamic evolution of materials observed using microscopy techniques based on He+ ions.

A deep geological disposal by using multiple barriers is favored for the long-term storage of high-level radioactive waste. A safe long-term storage means to analyze the applied materials according to their structural properties and stability in order to identify potential risks that could evolve during the operational phase and on the long run. So far, several concepts in Europe prefer cast iron and copper as canister materials (technical barrier) and bentonite as backfill- and buffering-/sealing material in between the canister and the host rock formation. In order to analyze the influence of naturally occurring microorganisms in bentonite on the respective barrier materials, different microcosm experiments were set up. These slurry experiments contain the Bavarian B25 bentonite, synthetic Opalinus Clay pore water or cap rock solution as well as copper- or cast iron plates in various combinations. During an incubation time of 400 days under anaerobic conditions at 37 °C, several bio-geochemical parameters (e.g. pH, redox potential and the concentration of minerals, sulfate, iron(II/III) and organic acids) were analyzed as well as the development of microbial diversity and incubated metal plates in the respective experiments. The obtained results provide insights into the complex interplay between bentonite, pore water, metals and microorganisms and can help to get a deeper understanding of the corrosion process of canister materials under the applied conditions.

In a previous study, EphB4 was demonstrated to be a positive regulator of A375 melanoma growth but a negative regulator of tumor vascularization and perfusion. To distinguish between EphB4 forward and ephrinB2 reverse signaling, we used the commercially available EphB4 kinase inhibitor NVP BHG712 (NVP), which was later identified as its regioisomer NVPiso. Since there have been reported significant differences between the inhibition profiles of NVP and NVPiso, we compared the influence of NVP and NVPiso on tumor characteristics under the same experimental conditions. Despite of different inhibitory profiles of NVP and NVPiso, the comparative study conducted here showed the same EphB4-induced effects in vivo as in the previous investigation. This confirmed the conclusion that EphB4-ephrinB2 reverse signaling is responsible for increased tumor growth as well as decreased tumor vascularization and perfusion. These results are further substantiated by microarrays showing differences between mock-transfected and EphB4-transfected (A375-EphB4) cells with respect to at least 9 angiogenesis-related proteins. Decreased expression of VEGF, Ang-1, and Akt/PKB, together with the increased expression of TIMP-1 and TGF-2, is consistent with the impaired vascularization of A375-EphB4 xenografts. Functional overexpression of EphB4 in A375-EphB4 cells was confirmed by activation of a variety of signaling pathways including JAK/STAT, Ras/Raf/MEK, and NFkB.

We conduct magnetic spherical Couette (MSC) flow experiments in the return flow instability regime with GaInSn as the working fluid, and the ratio of the inner to the outer sphere radii rᵢ/rₒ= 0.5, the Reynolds number Re = 1000, and the Hartmann number Ha ∈ [27.5, 40]. Rotating waves with different azimuthal wavenumbers m ∈ {2, 3, 4} manifest in certain ranges of Ha in the experiments, depending on whether the values of Ha were fixed or varied from different initial values. These observations demonstrate the multistability of rotating waves, which we attribute to the dynamical system representing the state of the MSC flow tending to move along the same solution branch of the bifurcation diagram when Ha is varied. In experiments with both fixed and varying Ha, the rotation frequencies of the rotating waves are consistent with the results of nonlinear stability analysis. A brief numerical investigation shows that differences in the azimuthal wavenumbers of the rotating waves that develop in the flow also depend on the azimuthal modes that are initially excited.

The China Institute of Atomic Energy (CIAE) proposed some of the China Experimental Fast Reactor (CEFR) neutronics start-up test data for the IAEA benchmark within the scope of the IAEA’s coordinated research activity. The coordinated research project (CRP) on “Neutronics Benchmark of CEFR Start-Up Tests” was launched in 2018. This benchmark aims to perform validation and verification of the physical models and the neutronics simulation codes by comparing calculation results against collected experimental data. Twenty-nine participating research organizations finished performing independent blind calculations and are refining their calculation results by referring to measurement data. The main objective of this benchmark is to improve understanding of the start-up of SFRs and validate the state-of-the-art fast reactor analysis computer codes against the recent experimental data obtained at the modern experimental SFR.
This paper introduces the following three kinds of reactivity measurements in the CEFR start-up test and presents the results by participants: temperature coefficient, sodium void reactivity, and swap reactivity. The measurements were done at the basic core in operation loading with fuel assemblies. First, for the measurement of temperature coefficients, ten sets of data were obtained by increasing and decreasing the temperature. For each temperature, the control rod position is changed to maintain the reactor as a critical. Second, sodium void reactivity is measured by replacing a fuel SA by vacuum-sealed SA and searching for the critical position of control rods. Third, for the measurement of the swap reactivity, fuel subassembly is replaced by SS subassembly, and SS subassembly is switched with one fuel subassembly. Swap reactivities are measured in two ways, with more than two control rods moving to find the criticality of the core in ‘Multiple Rods’ case, and only one control rod moving in the ‘Single Rod’ case. All three reactivities are obtained by a combination of control rod worth for changed rod position and criticality difference. Therefore, accuracy on control rod worth is important for benchmark calculation.
The comparison shows that uncertainty of calculations, modeling errors, and inaccurately determined control assembly worths make it challenging to calculate the temperature coefficient precisely. Depending on how modeling a vacuum-sealed fuel SA, the sodium void reactivity results from participants show large deviations. For swap reactivity calculation, the reactivity induced by the assembly swap is relatively larger than the temperature coefficient measurement. The swap reactivity calculation results from participants have similar trends and show good agreement with measurement.

Paper considers results of control rods worth calculation tests which have been done in IAEA coordinate research project (CRP) of China Experimental Fast Reactor (CEFR). Obtained results of more than 20 participants from 17 countries include neutronic calculations by using deterministic and stochastic codes. During RCM these results been compared by method of calculation and between it.
Calculation performed for all types of control rods used in CEFR as “light” for power control and “heavy” rods for shutdown and fuel burning compensation. Summary values of k-eff and rods worth are closed to each other, of course the some difference can be seen in comparison of two different methods of calculation but, in general, this difference not more 2 percent. For light rods relative deviation from average value is not more 10 % mostly. For heavy rods such deviation is not more 5%. Considering calculation results for group rods worth can be saying that difference between codes not more 2% in most cases.

From the analysis of the cyclotron resonance, we experimentally obtain the band structure of the threedimensional topological insulator based on a HgTe thin film. Top gating was used to shift the Fermi level in the film, allowing us to detect separate resonance modes corresponding to the surface states at two opposite film interfaces, the bulk conduction band, and the valence band. The experimental band structure agrees reasonably well with the predictions of the k · p model. Due to the strong hybridization of the surface and bulk bands, the dispersion of the surface states is close to parabolic in the broad range of the electron energies.

The objective of this WP is to identify and explain synergetic effects of VVER-1000 typical alloying elements in terms of irradiation-induced microstructures and mechanical property changes. Suitable materials are available in the neutron-irradiated condition from the LYRA-10 irradiation experiment. The approach is based on the application of complementary microstructural characterization techniques such as SEM, (S)TEM, APT, SANS, PAS to study low-Cu base and weld materials of intentionally varied contents of Ni, Mn and Si. In order to identify a synergetic effect of elements X and Y, low-X/low-Y, high-X/low-Y, low-X/high-Y and high-X/high-Y materials are to be compared and statistically evaluated with respect to mechanical property changes as well as type, composition, volume fraction, number density and size of irradiation-induced nano-features. Post-irradiation annealing allows the thermal stability of the defects to be evaluated. An additional objective is to provide a link between irradiated microstructures and mechanical property changes for highly irradiated VVER-1000 type steels.

In this talk, selected results of nanoindentation testing of unirradiated, neutron irradiated and ion irradiated (1 and 5 MeV) Fe-based materials are presented. The Nix-Gao approach is applied in order to extract the bulk-equivalent hardenss. Cross-sectional transmission electron microscopy shows how ion-irradiated microstructures look like. The available information is used to develop a microstructure-informed prediction model of irradiation hardening.

The talk presents the goals and intended work within the EU ENTENTE project. The focus is on work package 3, task 3.2 regarding microstructural characterisation planned within the project.

The talk presents the goals and intended work within the EU ENTENTE project. The focus is on work package 2, task 2.4 regarding the data collection contribution within the project.

We investigate AlN grown on 4H- and 6H-SiC substrates using Raman spectroscopy. We obtain the Raman peak shifts in 4H- and 6H-SiC substrates across the heterointerface and along the entire depth of the SiC layer. Using the earlier experimental prediction for the phonon deformation potential constants, we determine the stress tensor components in the 4H-SiC layer as a function of the distance from the AlN/SiC heterointerface and estimate the stress tensor value along the entire depth of the 6H-SiC layer. The maximum compressing stress values lie in the range of -1.7 GPa for the 4H-SiC/AlN heterostructure and in the range of -1.5 GPa for the 6H-SiC/AlN heterostructure.

In contrast to all other members of the RMn₂O₅ family with nonzero 4 f electrons (R = Nd to Lu), PrMn₂O₅ does not show any spin driven ferroelectricity in the magnetically ordered phase. By means of high-field electric polarization measurements up to 45 T, we have found that this exceptional candidate undergoes a spin driven multiferroic phase under magnetic field. X-ray magnetic circular dichroism studies up to 30 T at the Pr L₂ edge show that this ferroelectricity originates from and directly couples to the ferromagnetic component of the Pr³⁺spins. Experimental observations along with our generalized gradient-approximation+U calculations reveal that this exotic ferroelectric-ferromagnetic combination stabilizes through the exchange-striction mechanism solely driven by a 3d-4f-type coupling, as opposed to the other RMn₂O₅ members with 3d-3d driven ferroelectric-antiferromagnetic-type conventional type-II multiferroicity.

The correlative approach of real-time aerosol measurements with offline filter analysis and ParticleInduced X-ray Emission (PIXE) can significantly enhance the scope of aerosol studies. Aerosol particles have diverse physical and chemical properties, thus having a direct impact on air quality, cloud nucleation the planetary radiation balance, public health, etc. Essential information on the chemical composition of aerosol particles can be deduced from the elemental concentrations measured simultaneously for many elements by non-destructive and undemanding PIXE (Lucarelli, 2018). Furthermore, PIXE measurements can be performed with a focused beam allowing the analysis of individual particles (Biancato, 2006). Determining elemental concentrations is also important input information for aerosol source apportionment models and consequently abatement measures in order to improve air quality (Artaxo, 1999). Complementary information of aerosol particles structure down to nm scale, can be obtained with a Helium Ion Microscope (HIM), which, to our knowledge, has never been used before for aerosol characterization. The detection of secondary electrons and backscattered ions enables sub nm lateral resolution and large depth-of-field, also on insulating samples. In addition, a concurrent secondary ion mass spectrometry (ToF-SIMS) integrated in the HIM can provide insights of the composition of elements and molecules with imaging capabilities of sub 8 nm (Klingner, 2019).
In this study we coupled real-time measurements of optical properties of aerosols with an Aethalometer (Drinovec, 2015) and their carbon content with a Total Carbon Analyzer (Rigler, 2019) with PIXE and HIM analysis. Ambient aerosols were collected on quartz filters and quartz filters with Teflon coating during different pollution events (traffic or biomass burning dominated, Saharan dust dominated, etc.) at an urban background sampling site in Ljubljana, Slovenia (46o04’17’’N, 14o30’06’’E). The PM2.5 inlet was used for sampling carbonaceous aerosol while a virtual impactor was used for concentrating coarse particles during Saharan dust events.
PIXE measurements have been performed on these collected samples and compared to optical properties and source apportionment obtained by the online instruments. The PIXE measurements were performed across several hundred-micrometer regions and on individual points and results are presented including a description of the procedures for quantification. Complementary high-resolution imaging and sputtered ion analysis on single black carbon and Saharian dust aerosol particles was done on the HIM to study their structure and coating composition. The combination of all methods yields a comprehensive view of the aerosol particles.

HIFIS aims to ensure an excellent information environment for outstanding research in all Helmholtz research fields and a seamless and performant IT-infrastructure connecting knowledge from all centres. It will build a secure and easy-to-use collaborative environment with efficiently accessible ICT services from anywhere. HIFIS will also support the development of research software with a high level of quality, visibility and sustainability.
In this talk we will present current offers of the HIFIS platform. The focus is on the Software Services pillar of HIFIS.

Next generation sequencing (NGS) in combination with phage surface display (PSD) are powerful tools in the newly equipped molecular biology toolbox for the identification of specific target binding biomolecules. Application of PSD led to the discovery of manifold ligands in clinical and material research. However, limitations of traditional phage display hinder the identification process. Growth-based library biases and target-unrelated peptides often result in the dominance of parasitic sequences and the collapse of library diversity. This study describes the effective enrichment of specific peptide motifs potentially binding to arsenic as proof-of-concept using the combination of PSD and NGS. Arsenic is an environmental toxin, which is applied in various semiconductors as gallium arsenide and selective recovery of this element is crucial for recycling and remediation. The development of biomolecules as specific arsenic-binding sorbents is a new approach for its recovery. Usage of NGS for all biopanning fractions allowed for evaluation of motif enrichment, in-depth insight into the selection process and the discrimination of biopanning artefacts, e.g., the amplification-induced library-wide reduction in hydrophobic amino acid proportion. Application of bioinformatics tools led to the identification of an SxHS and a carboxy-terminal QxQ motif, which are potentially involved in the binding of arsenic. To the best of our knowledge, this is the first report of PSD combined with NGS of all relevant biopanning fractions.

A detection system based on a microchannel plate with a delay line readout structure has been developed to perform scanning transmission ion microscopy (STIM) in the helium ion microscope (HIM). This system is an improvement over other existing approaches since it combines the information of the scanning beam position on the sample with the position (scattering angle) and time of the transmission events. Various imaging modes such as bright and dark field or the direct image of the transmitted signal can be created by post-processing the collected STIM data. Furthermore, the detector has high spatial and time resolution, is sensitive to both ions and neutral particles over a wide energy range, and shows robustness against ion beam-induced damage. A special in-vacuum movable support gives the possibility of moving the detector vertically, placing the detector closer to the sample for the detection of high-angle scattering events, or moving it down to increase the angular resolution and distance for time-of-flight measurements. With this new system, we show composition-dependent contrast for amorphous materials and the contrast difference between small and high angle scattering signals. We also detect channeling related contrast on polycrystalline silicon, thallium chloride nanocrystals, and single crystalline silicon by comparing the signal transmitted at different directions for the same data set

We are daily exposed to a multitude of health hazardous airborne particulate matter with notable deposition in the fragile alveolar region of our lungs. Hence, there is a great need for identification and prediction of material-associated diseases, currently hindered due to the lack of in-depth understanding of causal relationships, in particular between acute exposures and chronic symptoms. By applying advanced microscopies and omics to in vitro and in vivo systems, together with in silico molecular modelling, we have here determined that the long-lasting response to a single exposure can originate from the interplay between the newly discovered nanomaterial quarantining and nanomaterial cycling between different lung cell types. This new insight finally allows us to predict the spectrum of lung inflammation associated with materials of interest using only in vitro measurements and in silico modelling potentially relating outcomes to material properties for large number of materials thus boosting safe-by-design-based material development. Because of its profound implications for animal-free predictive toxicology, our work paves the way to a more efficient and hazard-free introduction of numerous new advanced materials into our lives.

In order to determine the magnesium level in a titanium reduction retort by inductive methods, many interfering influences have to be considered to achieve precise measurement results. By using a look-up-table method, the magnesium level can be identified while taking into account the interfering effects of titanium sponge rings that are forming at the walls of the retort during the reduction process with their unknown geometrical and electrical parameters. This new method uses a combination of numerical simulations and measurements, whereby the simulation model is calibrated so that it represents the experimental setup as closely as possible. Previously we have presented purely theoretical studies on this method. Here, we demonstrate the practical feasibility of that method by performing measurements on a model experiment. This method is not limited to the production of titanium but can also be applied to other applications in metal production and processing.

We present an experimental study of time refraction of spin waves propagating in microscopic waveguides under the influence of time-varying magnetic fields. Using space- and time-resolved Brillouin light scattering microscopy, we demonstrate that the broken translational symmetry along the time coordinate can be used to in- or decrease the energy of spin waves during their propagation. This allows for a broadband and controllable shift of the spin-wave frequency. Using an integrated design of spin-wave waveguide and microscopic current line for the generation of strong, nanosecond-long, magnetic field pulses, a conversion efficiency up to 39% of the carrier spin-wave frequency is achieved, significantly larger compared to photonic systems. Given the strength of the magnetic field pulses and its strong impact on the spin-wave dispersion relation, the effect of time refraction can be quantified on a length scale comparable to the spin-wave wavelength. Furthermore, we utilize time refraction to excite spin-wave bursts with pulse durations in the nanosecond range and a frequency shift depending on the pulse polarity.

Theoretical and numerical studies on curved magnetic nano-objects predict numerous exciting effects that can be referred to as magneto-chiral effects, which do not originate from the intrinsic Dzyaloshinskii-Moriya interaction or surface-induced anisotropies. The origin of these chiral effects is the isotropic exchange or the dipole-dipole interaction present in all magnetic materials but renormalized by the curvature. Here, we demonstrate experimentally that curvature induced effects originating from the dipole-dipole interaction are directly observable by measuring spin-wave propagation in magnetic nanotubes with hexagonal cross section using time resolved scanning transmission X-ray microscopy. We show that the dispersion relation is asymmetric upon reversal of the wave vector when the propagation direction is perpendicular to the static magnetization. Therefore counter-propagating spin waves of the same frequency exhibit different wavelenghts. Hexagonal nanotubes have a complex dispersion, resulting from spin-wave modes localised to the flat facets or to the extremely curved regions between the facets. The dispersion relations obtained experimentally and from micromagnetic simulations are in good agreement. %The asymmetric spin-wave transport is present for all modes, promoting hexagonal nanotubes for magnonic applications. These results show that spin-wave transport is possible in 3D, and that the dipole-dipole induced magneto-chiral effects are significant.

Protein adsorption is the initial step in the response of biological systems to artificial surfaces and thus a ubiquitous phenomenon in biomedicine and tissue engineering. Here, we investigate the adsorption of the three globular proteins myoglobin (MGB), thyroglobulin (TGL), and bovine serum albumin (BSA) at flat and nanorippled SiO_x/Si and TiO_x/Ti surfaces. Despite having lateral and vertical dimensions of only about 30 nm and less than 2 nm, respectively, these nanoripples influence protein adsorption and adsorption-induced protein denaturation in a highly protein- and material-specific way. Adsorption of small, positively charged MGB results in preferential protein alignment along the nanoripples on both oxide surfaces. The larger and strongly negatively charged TGL forms layers of similar thickness on all four surfaces except the nanorippled TiO_x/Ti surface. Here, a smaller layer thickness is attributed to different denaturation states of the adsorbed proteins. Similarly, the smaller and less negatively charged BSA shows different degrees of denaturation on the flat and rippled SiO_x/Si surfaces. Our results thus demonstrate that topographic surface features with vertical dimensions well below 10 nm may have a surprisingly strong effect on protein adsorption and thus need to be considered in the interaction of biological systems even with apparently flat surfaces.

The safe enclosure of nuclear waste in deep-geological repositories is not only a challenge for engineers to build it, but also for geoscientist to predict that the eventually forming leaks do not lead to a contamination of the biosphere – and this for a period of up to one million years, as dictated by the slow decay of long-lived radionuclides. A precise, molecular-scale understanding of the retention processes at water/mineral interfaces is one of the fundamental requirements to improve the prediction of radionuclide migration by (reactive) transport models. These processes include physical and chemical sorption, and structural incorporation by existing or neoforming mineral phases. Interfacial redox reactions with structural or sorbed Fe(II) play a pivotal role during these processes, since Fe(II) is the most ubiquitous redox agent in the deep anoxic underground, and is released from steel canisters corroding under radiolytic H2 production. Synchrotron-based X-ray absorption spectroscopy is ideally suited to elucidate such processes, since it provides information on oxidation state, bonding and short-range structure of an element at the same time, and this in situ due to the high penetration depth and element-specifity of the used synchrotron radiation. I will show selected examples for a range of metals occurring in radwaste (Tc, U, Np, Pu, Am), while the observed processes are transferable to many other metals and metalloids of general geochemical interest.

A flexible sensor is presented for electrochemical detection of ascorbic acid in sweat based on single-step modified gold microelectrodes. The modification consists of electrodeposition of alginate membrane with trapped CuO nanoparticles. The electrodes are fabricated at a thin polyimide support and the soft nature of the membrane can withstand mechanical stress beyond requirements for skin monitoring. After characterization of the membrane via optical and scanning electron microscopy and cyclic voltammetry, the oxidative properties of CuO are exploited toward ascorbic acid for amperometric measurement at micromolar levels in neutral buffer and acidic artificial sweat, at ultralow applied potential (− 5 mV vs. Au pseudo-reference electrode). Alternatively, measurement of the horizontal shift of redox peaks by cyclic voltammetry is also possible. Obtaining a limit of detection of 1.97 μM, sensitivity of 0.103 V log (μM)−1 of peak shift, and linear range of 10–150 μM, the effect of possible interfering species present in sweat is minimized, with no observable cross-reaction, thus maintaining a high degree of selectivity despite the absence of enzymes in the fabrication scheme. With a lateral flow approach for sample delivery, repeated measurements show recovery in few seconds, with relative standard deviation of about 20%, which can serve to detect increased loss or absence of vitamin, and yet be improved in future by optimized device designs. This sensor is envisioned as a promising component of wearable devices for e.g. non-invasive monitoring of micronutrient loss through sweat, comprising features of light weight, low cost, and easy fabrication needed for such application.

Femtosecond (fs) x-ray pulses are a key tool to study the structure and dynamics of matter on its natural length and time scale. To complement radio-frequency accelerator-based large-scale facilities, novel laser-based mechanisms hold promise for compact laboratory-scale x-ray sources. Laser-plasma driven undulator radiation in particular offers high peak-brightness, optically synchronized few-fs pulses reaching into the few-nanometer (nm) regime. To date, however, few experiments have successfully demonstrated plasma-driven undulator radiation. Those that have, typically operated at single and comparably long wavelengths. Here we demonstrate plasma-driven undulator radiation with octave-spanning tuneability at discrete wavelengths reaching from 13 nm to 4 nm. Studying spontaneous undulator radiation is an important step towards a plasma-driven free-electron laser. Our specific setup creates a photon pulse, which closely resembles the plasma electron bunch length and charge profile and thus might enable novel methods to characterize the longitudinal electron phase space.

In the firrst-quantised worldline approach to quantum field theory, a long-standing problem has been to extend this formalism to amplitudes involving open fermion lines while maintaining the efficiency of the well-tested closed-loop case. In the present series of papers, we develop a suitable formalism for the case of quantum electrodynamics (QED) in vacuum (part one and two) and in a constant external electromagnetic field (part three), based on second-order fermions and the symbol map. We derive this formalism from standard field theory, but also give an alternative derivation intrinsic to the worldline theory. In this first part, we use it to obtain a Bern-Kosower type master formula for the fermion propagator, dressed with N photons in configuration as well as in momentum space.

Anatomical and functional imaging by means of computed tomography, magnetic resonance imaging, and positron emission tomography are, besides a thorough physical examination, of utmost importance for accurate staging of primary tumors in the head and neck region. This chapter deals with the particular advan-tages and disadvantages of those imaging techniques and gives practical guidance on how to employ these in radiation treatment planning.

The present work proposes a new approach for measuring the effective froth height on column trays. This approach is applied on the two-phase dispersion data gathered by a novel multi-probe sensor installed inside a large-scale tray column mockup. A physical explanation of the proposed approach describes how to distinguish between the liquid-continuous and gas-continuous regions in the froth. Accordingly, the effective froth height distributions are reported for selected tray loadings.

The fluvial-aeolian Upper Rotliegend sandstones from the Bebertal outcrop (Flechtingen High, Germany) are the famous reservoir analog for the deeply-buried Upper Rotliegend gas reservoirs of the Southern Permian Basin (SPB). While most diagenetic and reservoir quality investigations are conducted on a meter scale, there is an emerging consensus that significant reservoir heterogeneity is inherited from diagenetic complexity at smaller scales. In this study, we utilize information about diagenetic products and processes at the pore-and plug-scale and analyze their impact on the heterogeneity of porosity, permeability, and cement patterns. Eodiagenetic poikilitic calcite cements, illite/iron oxide grain coatings, and the amount of infiltrated clay are responsible for mm-to cm-scale reservoir heterogeneities in the Parchim formation of the Upper Rotliegend sandstones. Using the Petrel E&P software platform, spatial fluctuations and spatial variations of permeability, porosity, and calcite cements are modeled and compared, offering opportunities for predicting small-scale reservoir rock properties based on diagenetic constraints.

Germanium is a nonpolar semiconductor with missing one-phonon absorption. The absence of a Reststrahlen band enables the generation of a gapless THz spectrum spreading up to 13 THz [1], limited only by the duration of the excitation and detection laser pulses. However, in spite of other promising properties including low bandgap and small effective mass, the long, µs-scale recombination time arising from the indirect bandgap of intrinsic germanium has been prohibitive for practical application as photoconductive THz emitters. Although not essential for broadband THz emission, shorter recombination times are necessary to ensure complete carrier recombination between subsequent laser pulses and to make these emitters compatible with standard modelocked laser systems operating at pulse repetition rates up to hundreds of MHz.
By introducing deep traps into germanium via gold implantation, we have reduced the carrier lifetime to sub-nanosecond values. Fabricated on this Au-implanted Ge material, we have demonstrated a photoconductive THz antenna which is compatible with modelocked fibre lasers operating at wavelengths of 1.1 and 1.55 m and with pulse repetition rates of 78 MHz [2] and potentially up to several hundreds of MHz. Reaching up to 70 THz bandwidth, which is almost one order of magnitude higher than that of existing state-of–the-art photoconductive THz emitters fabricated on GaAs or InGaAs, our approach points towards the possibility of compact, high-bandwidth THz photonic devices compatible with Si CMOS technology.
[1] A. Singh et al., ACS Photonics 5, 2718 (2018).
[2] A. Singh et al., Light Science & Applications 9, 30 (2020).

This presentation reviews some recent experiments using free-electron-laser-based narrow-band as well as tabletop-laser-based single-cycle terahertz (THz) fields for exploring electronic properties in semiconducting GaAs/InGaAs core/shell nanowires (NW) [1]. In undoped NW, charge carriers are optically excited by near-infrared pulses and probed by strong single-cycle THz fields up to 0.6 MV/cm. The photoexcited charge carriers exhibit a pronounced plasmon resonance, which undergoes a systematic redshift and a suppression of its spectral weight, which indicates a drop of the electron mobility at the highest fields to about half of the original value [2]. In n-type NWs, intense narrowband THz excitation causes a nonlinear plasmonic response, which manifests itself by a similar pronounced red shift of the plasma resonance. This nonlinearity is investigated by scattering-type scanning near-field infrared microscopy on individual NWs. For NW doped with Si to a concentration of 9x10^18 cm^-3, a spectrally sharp plasma resonance, located at a photon energy of 125 meV for weak excitation, undergoes a power-dependent redshift to about 95 meV [3]. In these experiments, the observed behavior is attributed to a pronounced increase of the average electron effective mass caused by transient carrier heating and electron intervalley transfer. The results quantify the nonlinear transport regime in GaAs-based nanowires and show their high potential for development of nanodevices operating at THz frequencies.
[1] L. Balaghi et al., Widely tunable GaAs band gap via strain engineering in core/shell nanowires, Nature Comm. 10, 2793 (2019)
[2] R. Rana et al., Nonlinear terahertz field-induced charge transport and transferred-electron effect in InGaAs nanowires, Nano Lett. 20, 3225 (2020)
[3] D. Lang et al., Nonlinear plasmonic response of doped nanowires observed by infrared nanospectroscopy, Nanotechnol. 30, 084003 (2019)

This talk does not have an abstract.

CeRhIn₅ provides a textbook example of quantum criticality in a heavy fermion system: Pressure suppresses local-moment antiferromagnetic (AFM) order and induces superconductivity in a dome around the associated quantum critical point (QCP) near p_c ≈ 23 kbar. Strong magnetic fields also suppress the AFM order at a field-induced QCP at B_c ≈ 50 T. In its vicinity, a nematic phase at B* ≈ 28 T characterized by a large in-plane resistivity anisotropy emerges. Here, we directly investigate the interrelation between these phenomena via magnetoresistivity measurements under high pressure. As pressure increases, the nematic transition shifts to higher fields, until it vanishes just below p. While pressure suppresses magnetic order in zero field as pc is approached, we find magnetism to strengthen under strong magnetic fields due to suppression of the Kondo effect. We reveal a strongly nonmean-field-like phase diagram, much richer than the common local-moment description of CeRhIn would suggest.

The magnetization of SmFe₁₁Ti single crystals has been measured along the principal crystallographic directions in steady (14 T) and pulsed (43 T) magnetic fields. The fourfold symmetry axis [001] is an easy magnetization direction. The magnetization curves measured in directions perpendicular to [001] are remarkable in two ways: (i) They do not depend on orientation of H within the basal plane; (ii) at low temperature they are S shaped, with an inflection point at about 0.6 times saturation magnetization. These two facts enable us to conclude that three out of five crystal field parameters of SmFe₁₁Ti are negligibly small; only A⁰ ₂ and A⁰ ₆ are essentially nonzero. A comparison with an isomorphous compound DyFe₁₁Ti reveals a dramatic disparity of their crystal fields, especially as regards A⁴ ₄, nearly zero in SmFe₁₁Ti but outstandingly large in DyFe₁₁Ti.

We report on a comprehensive characterization of the newly synthesized Cu²⁺-based molecular magnet Cu(pz)₂ (2-HOpy)₂ K, as revealed by μ⁺SR. In applied magnetic fields, our ¹H-NMR data reveal a strong increase of the magnetic anisotropy, manifested by a pronounced enhancement of the transition temperature to commensurate long-range order at T_N = 2.8 K and 7 T.

Numerous materials feature unexplained phases with invisible or hidden order of electronic origin. A particularly mysterious case is that of Tb₂Ti₂O₇, which avoids magnetic order to the lowest temperatures, but nevertheless has an unexplained second-order phase transition near T = 0.5 K. Our ultrasound measurements of Tb₂Ti₂O₇ provide direct evidence of a huge softening followed by strong hardening of the structural lattice below T = 0.5 K. In the absence of magnetic order at this temperature, our results provide conclusive evidence for the proposed quadrupolar order and emphasize the importance of higher-order multipolar interactions in rare-earth frustrated magnets.

We propose a solution to the longstanding problem of experimentally reproducing the metal pad roll instability at room temperature. Combining theoretical arguments with numerical simulations we show that the instability can occur in a centimeter scale set-up, with reasonable values of the magnetic field and electrical current and using either gallium with mercury (immiscible fluid pair) or gallium with GaInSn eutectic alloy (miscible fluid pair).

The photonic bandgap and localization in photonic crystals can be effectively modulated by energetic ion beams owing to the induced modification of the thickness and refractive indices of the materials. In this work, the modulation of photonic bandgap and defect modes in 1D all-dielectric photonic crystals is investigated theoretically and experimentally by using carbon (C⁵⁺) ion irradiation. It is found that the photonic bandgap and defect mode have a remarkable hypsochromic shift under the C⁵⁺ ion irradiation. The degree of the blueshift mainly depends on the reduction of the material thickness that is nearly proportional to the fluences of C⁵⁺ ions. The blueshift of the band edges and defect modes shows a step-like behavior from transparency to opacification (near-zero transmittance or high reflectance) or a converse trend. The work paves a new way to tailor the photonic crystals toward the development of novel devices with tunable specific wavelengths and wavebands.

Reimbursement is a key factor in defining which resources are made available to ensure quality, efficiency, availability,
and access to specific health-care interventions. This Policy Review assesses publicly funded radiotherapy
reimbursement systems in Europe. We did a survey of the national societies of radiation oncology in Europe, focusing
on the general features and global structure of the reimbursement system, the coverage scope, and level for typical
indications. The annual expenditure covering radiotherapy in each country was also collected. Most countries have a
predominantly budgetary-based system. Variability was the major finding, both in the components of the treatment
considered for reimbursement, and in the fees paid for specific treatment techniques, fractionations, and indications.
Annual expenses for radiotherapy, including capital investment, available in 12 countries, represented between 4·3%
and 12·3% (average 7·8%) of the cancer care budget. Although an essential pillar in multidisciplinary oncology,
radiotherapy is an inexpensive modality with a modest contribution to total cancer care costs. Scientific societies and
policy makers across Europe need to discuss new strategies for reimbursement, combining flexibility with incentives
to improve productivity and quality, allowing radiation oncology services to follow evolving evidence.

The combination of the beneficial effects of high dose-rate Flash-RT and proton depth dose distribution promise the differential sparing of normal tissue under similar tumour treating efficacy. However, of the two published attempts [1,2] made at clinical proton facilities, one in vivo study on zebrafish embryo was not able to measure a Flash effect [2]. In the discussion of this experiment, the zebrafish model, a non-ideal pulse-time-regime and an uncertain oxygen level during irradiation were identified as potential explanations for the missing Flash effect. In order to investigate these parameters in detail an experiment was scheduled at the research electron accelerator ELBE at HZDR, because an electron Flash effect was already demonstrated for zebrafish embryo [3]. The highly variable pulse structure of ELBE enables to deliver the dose either in therapy like quasi-continuous (cw) beams or as electron Flash irradiation.
Zebrafish embryo were irradiated with 40 Gy with pulse dose rates of 109 Gy/s and mean dose rates of 106 Gy/s in comparison to 0.1 Gy/s with cw irradiation. In addition to this, the Oxylite system was applied to measure and control oxygen depletion kinetics in sealed embryo samples. A protective Flash effect was seen for most endpoints ranging from 4 % less reduction in embryo length to about 20 – 25 % less embryo with spinal curvature and pericardial oedema, relative to cw-irradiation. The reduction of partial oxygen pressure below atmospheric levels results in higher protection, the more the lower the oxygen level.
In conclusion, the Flash experiment at ELBE show that the zebrafish embryo model is appropriate for the study of the radiobiological response of high dose rate irradiation. A sufficiently pulse dose seems to be more important than pulse dose rate and the partial oxygen pressure during irradiation plays a pivotal role.
[1] Diffenderfer et al.: https://doi.org/10.1016/j.ijrobp.2019.10.049
[2] Beyreuther et al.: https://doi.org/10.1016/j.radonc.2019.06.024
[3] Vozenin et al.: https://doi.org/10.1016/j.clon.2019.04.001

Room-temperature broadband infrared photoresponse in Si is of great interest for the development of on-chip complementary metal-oxide-semiconductor (CMOS)-compatible photonic platforms. One effective approach to extend the room-temperature photoresponse of Si to the mid-infrared range is the so-called hyperdoping. This consists of introducing deep-level impurities into Si to form an intermediate band within its bandgap enabling a strong intermediate band-mediated infrared photoresponse.Typically, impurity concentrations in excess of the equilibrium solubility limit can be introduced into the Si host either by pulsed laser melting of Si with a gas-phase impurity precursor, by pulsed laser mixing of a thin-film layer of impurities atop the Si surface or by ion implantation followed by a sub-second annealing step. In this review, a conspectus of the current status of room-temperature infrared photoresponse in hyperdoped Si by ion implantation followed by nanosecond-pulsed laser annealing is provided. The possibilities of achieving room-temperature broadband infrared photoresponse in ion beam-hyperdoped Si with different deep-level impurities are discussed in terms of material fabrication and device performance. The thermal stability of hyperdoped Si with deep-level impurities is addressed with special emphasis on the structural and the opto-electronic material properties. The future perspectives of achieving room-temperature Si-based broadband infrared photodetectors are outlined.

Hyperdoping Si with chalcogens is a topic of great interest due to the strong sub-band-gap absorption exhibited by the resulting material, which can be exploited to develop broadband room-temperature infrared photodetectors using fully Si-compatible technology. Here, we report on the critical behavior of the impurity-driven insulator-tometal transition in Te-hyperdoped Si layers fabricated via ion implantation followed by nanosecond pulsed-laser melting. Electrical transport measurements reveal an insulator-to-metal transition, which is also confirmed and understood by density functional theory calculations. We demonstrate that the metallic phase is governed by a power-law dependence of the conductivity at temperatures below 25 K, whereas the conductivity in the insulating phase is well described by a variable-range hopping mechanism with a Coulomb gap at temperatures in the range of 2–50 K. These results show that the electron wave function in the vicinity of the transition is strongly affected by the disorder and the electron-electron interaction.

2D conjugated metal-organic frameworks (2D c-MOFs) are emerging as a novel class of conductive redox-active materials for electrochemical energy storage. However, developing 2D c-MOFs as flexible thin-flm electrodes have been largely limited, due to the lack of capability of solution-processing and integration into nanodevices arising from the rigid powder samples by solvothermal synthesis. Here, the synthesis of phthalocyanine-based 2D c-MOF (Ni2[CuPc(NH)8]) nanosheets through ball milling mechanical exfoliation method are reported. The nanosheets feature with average lateral size of ≈160 nm and mean thickness of ≈7 nm (≈10 layers), and exhibit high crystallinity and chemical stability as well as a p-type semiconducting behavior with mobility of ≈1.5 cm2 V−1 s−1 at room temperature. Benefting from the ultrathin feature, the nanosheets allow high utilization of active sites and facile solution-processability. Thus, micro-supercapacitor (MSC) devices are fabricated mixing Ni2[CuPc(NH)8] nanosheets with exfoliated graphene, which display outstanding cycling stability and a high areal capacitance up to 18.9 mF cm−2; the performance surpasses most of the reported conducting polymers-based and 2D materials-based MSCs.

Two-dimensional conjugated metal–organic frameworks (2D c-MOFs) have recently emerged for potential applications in (opto-)electronics, chemiresistive sensing, and energy storage and conversion, due to their excellent electrical conductivity, abundant active sites, and intrinsic porous structures. However, developing ultrathin 2D c-MOF nanosheets (NSs) for facile solution processing and integration into devices remains a great challenge, mostly due to unscalable synthesis, low yield, limited lateral size and low crystallinity.
Here, we report a surfactant-assisted solution synthesis toward ultrathin 2D c-MOF NSs, including HHBCu (HHB ¼ hexahydroxybenzene), HHB-Ni and HHTP-Cu (HHTP ¼ 2,3,6,7,10,11-hexahydroxytriphenylene). For the first time, we achieve single-crystalline HHB-Cu(Ni) NSs featured with a thickness of 4–5 nm (~8–10 layers) and a lateral size of 0.25–0.65 mm2, as well as single-crystalline HHTP-Cu NSs with a thickness of ~5.1 + 2.6 nm (~10 layers) and a lateral size of 0.002–0.02 mm2.Benefiting from the ultrathin feature, the synthetic NSs allow fast ion diffusion and high utilization of active sites. As a proof of concept, when serving as a cathode material for Li-ion storage, HHB-Cu NSs
deliver a remarkable rate capability (charge within 3 min) and long-term cycling stability (90% capacity retention after 1000 cycles), superior to the corresponding bulk materials and other reported MOF cathodes.

Monte Carlo (MC) simulations are indispensable for many research and advanced clinical questions in proton therapy (PT). However, the necessary site-specifc modeling of a double scattering (DS) PT system is extensive and challenging and requires a clear strategy. This work describes a comprehensive method for precise and accurate modeling of a DS nozzle that minimizes additional measurement effort. A detailed model of the IBA universal nozzle is created within the TOPAS simulation framework. This model is subsequently fine-tuned using a step by step procedure to match the same dose profiles used for the commissioning of the treatment planning system. In the proposed bottom-up approach, the geometry of beam-shaping elements is first adjusted to measured quantities and then the beam and model properties are optimized using iterative methods. The resulting dose distributions are validated with a set of independent measurement data to estimate the achieved quality. The resulting simulated dose distributions agree well with the data and show residual range diifferences typically better than 0.5 mm. The shape of the SOBP plateau regions is accurately reproduced with a spread of the residuals below 1% (i.e., near to the statistical limit) over a large part of the machine settings. The simulated lateral dose profiles, although not directly included in the optimization, match the shape of the validation data better than 0.14 mm. The minimal measurement effort and high-precision proton field modeling make this method attractive, in particular, for retrospective beam modeling needed in clinical outcome studies after DS treatment.

Much of contemporary landslide research is concerned with predicting and mapping susceptibility to slope failure. Many studies rely on generalised linear models with environmental predictors that are trained with data collected from within and outside of the margins of mapped landslides. Whether and how the performance of these models depends on sample size, location, or time remains largely untested. We address this question by exploring the sensitivity of a multivariate logistic regression—one of the most widely used susceptibility models—to data sampled from different portions of landslides in two independent inventories (i.e. a historic and a multi-temporal) covering parts of the eastern rim of the Fergana Basin, Kyrgyzstan. We find that considering only areas on lower parts of landslides, and hence most likely their deposits, can improve the model performance by >10% over the reference case that uses the entire landslide areas, especially for landslides of intermediate size. Hence, using landslide toe areas may suffice for this particular model and come in useful where landslide scars are vague or hidden in this part of Central Asia. The model performance marginally varied after progressively updating and adding more landslides data through time. We conclude that landslide susceptibility estimates for the study area remain largely insensitive to changes in data over about a decade. Spatial or temporal stratified sampling contributes only minor variations to model performance. Our findings call for more extensive testing of the concept of dynamic susceptibility and its interpretation in data-driven models, especially within the broader framework of landslide risk assessment under environmental and land-use change.

This chapter considers the case of B2-ordered alloys that are initially non-ferromagnetic and where the introduction of lattice defects can cause the onset of ferromagnetism. This disorder-induced ferromagnetism is confined to the regions where the defects are concentrated. In general, the lattice can be thermally re-ordered, removing the defects and erasing the magnetized regions. Using B2 Fe60Al40 thin films as a prototype, the use of ion irradiation as well as pulsed laser irradiation for inducing antisite defects in the crystalline lattice is demonstrated. Ion beams can be applied as broad beams in combination with shadow masks for printing magnetic patterns over large areas, or focused down to approximately nanometer diameters for stylus-like writing of nanomagnets of desired geometries. The patterning resolution is limited by the lateral scattering of ions and can be estimated by semi-empirical modelling, described in this chapter. In the case of laser pulsing, disordering can be induced at thin film surfaces for pulse fluences above the melting threshold. Pulsing below the threshold can lead to surface re-ordering, erasing the magnetic regions and achieving all-laser re-writeable patterning. Localized disordering of B2 ordered systems thus enables a versatile path to embedding highly resolved non-volatile magnets at room temperature, with potential in magnetic device applications.

Background: Due to the beneficial inverse physical depth-dose profile, proton radiotherapy (PT) offers the potential to reduce normal tissue toxicity by depositing the maximum dose within the tumor volume while sparing the surrounding tissue. However, range uncertainties and necessary clinical safety margins in combination with varying relative biological effectiveness may result in a critical dose in the normal tissue. Dedicated preclinical studies are needed to assess and better understand potential adverse effects of PT and to develop potential biomarkers and countermeasures for backtranslation into clinics.
For this purpose, a high-precision image-guided proton irradiation setup for small animals was established at the University Proton Therapy Dresden that mimics the clinical workflow, including pre-treatment imaging, treatment planning and image-guided brain irradiation.
The right hippocampus of C57BL/6 and C3H/HeN mice was irradiated to study the dose- and time-dependent radiation response of mouse brain tissue after short or long-term follow-up analysis. A Monte Carlo model of the proton beam was designed in the simulation toolkit TOPAS to calculate the dose distributions in vivo and to correlate the outcome with proton dose and LET.
The geometric accuracy of proton irradiation, detailed dose simulations on mouse CT and cell-based assessment enable a biologically and spatially resolved analysis of short-term radiation response and RBE. In addition, the long-term follow up over six month provides first insights into the formation of normal tissue damage in mouse brain after PT.

Radiation induced late side effects such as cognitive decline and normal tissue complications can severely affect quality of life and outcome in long-term survivors of brain tumors. Proton therapy offers a favorable depth-dose deposition with the potential to spare tumor-surrounding normal tissue, thus potentially reducing such side effects. In this study, we describe a preclinical model to reveal underlying biological mechanisms caused by precise high-dose proton irradiation of a brain subvolume.
We studied the dose- and time-dependent radiation response of mouse brain tissue, using a high-precision image-guided proton irradiation setup for small animals established at the University Proton Therapy Dresden. The right hippocampal area of ten C57BL/6 and ten C3H/He mice was irradiated. Both strains consisted of four groups treated with increasing doses (0 – 85 Gy and 0 – 80 Gy, respectively). Follow-ups were performed up to six months, including longitudinal monitoring of general health status and regular contrast-enhanced magnetic resonance imaging (MRI) of mouse brains. These findings were related to comprehensive final histological analysis.
In mice of the highest dose group, first symptoms of blood-brain barrier (BBB) damage appeared one week after irradiation, while a dose-dependent delay in onset was observed for lower doses. MRI contrast agent leakage occurred in the irradiated brain areas and was progressive in the higher dose groups. Mouse health status and survival corresponded to the extent of contrast agent leakage. Histological analysis revealed tissue changes such as vessel abnormalities, gliosis, and granule cell dispersion, which also partly affected the non-irradiated contralateral hippocampus.
All observed effects depended strongly on the prescribed radiation doses and the outcome, i.e. survival, image changes and tissue alterations, within an experimental dose cohort was very consistent. A derived dose-response model will determine doses in future experiments and may support the formulation of clinical hypotheses on brain toxicity after proton therapy.

Synchrotron radiation (SR)-based X-ray methods are powerful analytical tools for several purposes and we widely use them for probing the degradation mechanisms of inorganic artists’ pigments in paintings, including chrome yellows (PbCr1-xSxO4; 0 ≤x≤0.8), a class of compounds often found in Van Gogh masterpieces. However, the high intensity and brightness of SR beams raise important issues regarding potential damages of the analyzed samples. A thorough knowledge of the SR X-ray sensitivity of each class of pigment in the painting matrix is therefore required to find analytical strategies that contribute to minimize the damage for preserving the integrity of the analyzed sample and to avoid misinterpretation of the data. Here, we employ a combination of Cr K-edge X-ray absorption near edge structure (XANES) spectroscopy, Cr-Kβ X-ray emission spectroscopy (XES) and X-ray diffraction (XRD) to monitor and quantify the effects of SR X-rays on the stability of chrome yellows and related Cr-compounds and to define strategies for mitigating their damage. We found that the SR X-ray beam exposure induces changes in the oxidation state and local coordination environment of Cr-ions and leads to a loss of the compound’s crystalline structure. The extent of X-ray damage depends on some intrinsic properties of the samples (chemical composition of the pigment as well as the presence/absence and nature of the binder) and it can be minimized by optimizing the overall fluence/dose released to the samples and by working in vacuum and cryogenic conditions.

In recent years, a number of drugs targeting the prostate specific-membrane antigen (PSMA) have become important tools in the diagnosis and treatment of prostate cancer. In the present work, we report on the synthesis and preclinical evaluation of a series of 18F-labeled PSMA ligands for diagnostic application based on the theragnostic ligand PSMA-617. By applying modifications to the linker-structure, insight into the structure-activity relationship could be gained highlighting the importance of hydrophilicity and stereoselectivity on interaction with PSMA and hence the biodistribution. Selected compounds were co-crystallized with the PSMA-protein and analyzed by X-ray with mixed results. Amongst these, PSMA-1007 (compound 5) showed the best interaction with the PSMA protein. The respective radiotracer [18F]PSMA-1007 was translated into the clinic and is in the meantime subject of advanced clinical trials.

Simulations allow us to get a detailed understanding of processes inside plasmas not directly accessible to experiments. They are therefore a very important tool for theoretical and experimental research and are continually being improved.
One improvement in development is the direct inclusion of atomic physics in Particle in Cell(PIC) simulations, a specific simulation technic used for non fluid-like plasmas.
In this talk I will describe possible approaches to realise atomic physics in PIC and give a short introduction to PIC algorithms and atomic physics in plasmas.

Die Erfindung betrifft eine Verbindung, die

• eine Calixaren-Einheit, die n Phenoleinheiten aufweist, wobei n 4, 5, 6 oder 8 ist;
• eine Ethereinheit, die unter Ausbildung eines Kronenethers an die Calixaren-Einheit gebunden ist; und
• zumindest eine Sulfonsäureamid-Einheit der Formel

Die Erfindung betrifft eine Tomographievorrichtung und ein Tomographieverfahren zum Abbilden der inneren Struktur eines Untersuchungsobjekts, wobei aufeinanderfolgend in einer ersten, einer zweiten und einer dritten Scanebene Strahlung zum tomographischen Untersuchen des Untersuchungsobjekts erzeugt wird und die Strahlung mittels einer Detektorvorrichtung mit mehreren Detektorsegmenten erfasst wird, wobei jedes Detektorsegment einen in der ersten Scanebene angeordneten ersten Strahlungsdetektor, einen in der zweiten Scanebene angeordneten zweiten Strahlungsdetektor und einen in der dritten Scanebene angeordneten dritten Strahlungsdetektor zum Erfassen der Strahlung unter Erzeugung von Detektorsignalen aufweist, und wobei die Detektorsignale des ersten und des dritten Strahlungsdetektors mittels eines ersten Verstärkers verstärkt werden und die Detektorsignale des zweiten Strahlungsdetektors mittels eines zweiten Verstärkers verstärkt werden.

Die Erfindung betrifft einen Wärmeübertrager mit wenigstens einer Trennwand und wenigstens von einer Seite der Trennwand abstehenden und die Oberfläche der Trennwand vergrößernden Oberflächenelementen, die von einem Fluid umströmbar sind. Dabei weisen die Oberflächenelemente Verstärkungswülste und zwischen den Verstärkungswülsten befindliche Flächenbereiche auf, wobei sich die Verstärkungswülste von der Trennwand ausgehend erstrecken und eine kreisrunde oder ovale Querschnittform haben. Die Verstärkungswülste erstrecken sich ausgehend von der Trennwand über mindestens einen Teil der Höhe des Oberflächenelementes und verjüngen sich von der Trennwand aus entlang der Höhe der Oberflächenelemente. Die Oberflächenelemente weisen eine Vielzahl konvexer Aussparungen auf, wobei jede der konvexen Aussparungen in einem der Flächenbereiche zwischen zwei Verstärkungswülsten angeordnet ist und sich von einer Außenkante des Oberflächenelementes erstreckt. Der Scheitelpunkt der konvexen Aussparung liegt bei einer Höhe größer als oder gleich 30% und kleiner als oder gleich 70% der gesamten Höhe des Oberflächenelementes, wobei die Höhe ausgehend von der Trennwand gemessen ist.

Die Erfindung betrifft eine Verbindung der allgemeinen Formel I worin Ar ein Pyridin-Ring ist; R¹ Wasserstoff oder Fluor ist; R² aus der Gruppe ausgewählt ist, die aus Wasserstoff, Hydroxy, Halogen, -CN, -NO₂, -N(R³R⁴), -(CR⁹R¹⁰)ₚ-C(O)-N(R⁵R⁶), -(CR⁹R¹⁰)q-CHO, -(CR⁹R¹⁰)r-C(O)-(CR⁹R¹⁰)s-R⁷, -(CR⁹R¹⁰)t-O-(CR⁹R¹⁰)v-R⁸ oder einer verzweigten oder unverzweigten, substituierten oder unsubstituierten C₁-C₁₂-Alkylgruppe besteht; R³, R⁴, R⁵, R⁶ und R⁷ unabhängig voneinander jeweils Wasserstoff oder eine verzweigte oder unverzweigte, substituierte oder unsubstituierte C₁-C₁₂-Alkylgruppe sind; R⁸ eine verzweigte oder unverzweigte, substituierte oder unsubstituierte C₁-C₁₂-Alkylgruppe ist; R⁹ und R¹⁰ unabhängig voneinander bei jedem Vorkommen Wasserstoff, Halogen, verzweigtes oder unverzweigtes, unsubstituiertes oder substituiertes C₁-C₁₂-Alkyl oder unsubstituiertes oder substituiertes C₂-C₆-Alkenyl sind; 1 1, 2, 3 oder 4 ist m 0, 1 oder 2 ist, mit der Maßgabe, dass 1 + m nicht größer als 4 ist; n 1, 2 oder 3 ist; und p, q, r, s, t und v unabhängig voneinander 0 oder eine Ganzzahl von 1 bis 6 sind. Außerdem ist eine Präkursor-Verbindung zur Herstellung einer Verbindung der Formel I vorgesehen, die anstelle einer Gruppe R¹ eine Abgangsgruppe aufweist.

Ein Markierungsvorläufer umfasst einen Chelator oder eine Fluorierungsgruppe für die Radiomarkierung mit ⁴⁴Sc, ⁴⁷Sc, ⁵⁵Co, ⁶²Cu, ⁶⁴Cu, ⁶⁷Cu, ⁶⁶Ga, ⁶⁷Ga, ⁶⁸Ga, ⁸⁹Zr, ⁸⁶Y, ⁹⁰Y, ⁹⁰Nb, ⁹⁹ᵐTc, ¹¹¹In, ¹³⁵Sm, ¹⁴⁰Pr, ¹⁵⁹Gd, ¹⁴⁹Tb, ¹⁶⁰Tb, ¹⁶¹Tb, ¹⁶⁵Er, ¹⁶⁶Dy, ¹⁶⁶Ho, ¹⁷⁵Yb, ¹⁷⁷Lu, ¹⁸⁶Re, ¹⁸⁸Re, ¹¹³Bi und ¹¹⁵Ac beziehungsweise mit ¹⁸F, ¹³¹I oder ¹¹¹At und einen oder zwei biologische Targetingvektoren, die über eine oder mehrere Quadratsäuregruppen mit dem Chelator oder der Fluorierungsgruppe gekoppelt sind.

Die Erfindung betrifft eine Tomographievorrichtung und ein Tomographieverfahren zum Abbilden der inneren Struktur eines Untersuchungsobjekts, wobei ein Elektronenstrahl derart über ein erstes Target mit mehreren Durchtrittsöffnungen geführt wird, dass der Elektronenstrahl nacheinander mehrere der Durchtrittsöffnungen überstreicht, wobei an dem ersten Target erste Röntgenstrahlung zum Durchstrahlen des Untersuchungsobjekts entsteht, wenn der Elektronenstrahl abseits der Durchtrittsöffungen auf das erste Target trifft, und wobei der Elektronenstrahl durch das erste Target hindurchtritt und mittels einer zwischen das erste Target und ein zweites Target angelegten elektrischen Spannung auf das zweite Target beschleunigt wird, wenn der Elektronenstrahl auf eine der Durchtrittsöffnungen gerichtet ist, wobei an dem zweiten Target zweite Röntgenstrahlung zum Durchstrahlen des Untersuchungsobjekts
entsteht.

The impact of the contamination of living organisms by actinide elements has been a constant subject of attention since the 1950s. But to date still little is understood. Ferritin is the major storage and regulation protein of iron in many organisms, it consists of a protein ring and a ferrihydric core at the center. This work sheds light on the interactions of early actinides (Th, Pu) at oxidation state +IV with ferritin and its ability to store those elements at physiological pH compared to Fe. The Ferritin ‐ thorium load curve suggests that Th(IV) saturates the protein (2840 Th atoms per ferritin) in a similar way that Fe does on the protein ring. Complementary spectroscopic techniques (Spectrophotometry, Infrared Spectroscopy and X‐ray Absorption Spectroscopy) were combined with Molecular Dynamics to provide a structural model of the interaction of Th(IV) and Pu(IV) with ferritin. Comparison of spectroscopic data together with MD calculations suggests that Th(IV) and Pu(IV) are complexed mainly on the protein ring and not on the ferrihydric core. Indeed from XAS data, there is no evidence of Fe neighbors in the Th and Pu environments. On the other hand, carboxylates from amino acids of the protein ring and a possible additional carbonate anion are shaping the cation coordination spheres. This thorough description from a molecular view point of Th(IV) and Pu(IV) interaction with ferritin, an essential iron storage protein, is a cornerstone in comprehensive nuclear toxicology.

We present a numerical approach to obtain the Ferromagnetic Resonance (FMR) spectra of micrometer- and nano-sized magnetic elements by micromagnetic simulations. Mimicking common experimental conditions, a static magnetic field is applied and a linearly polarized oscillating magnetic field is used to excite magnetization dynamics. A continuous single-frequency excitation is utilized, which permits to study the steady-state dynamics in space- and time-domain. This gives direct access to resonance fields, line widths and relative amplitudes as observed in the experiments, which is not easily accessible in pulsed schemes and allows for a one-to-one identification between simulation and experiment. Similar to numerical approaches using pulsed excitations the phases, ellipticity and spatial mode profiles of the spin-wave excitations may also be accessed. Using large excitation powers we then showcase that one can additionally study nonlinear responses by this method such as the nonlinear shift of the resonance fields and the fold-over of the absorption lines. Since the dynamic susceptibility is directly determined from standard outputs of common micromagnetic codes, the presented method is robust, efficient and easy-to-use, adding to its practical importance.

We study the non-linear Breit-Wheeler process γ⃗ ′+L⃗ →e++e− in the interaction of linearly polarized probe photons (γ⃗ ′) with a linearly polarized laser beam (L⃗ ). In particular, we consider the asymmetry of the total cross section and the azimuthal electron distributions when the polarizations of the photon and laser beams in the initial state are mutually perpendicular or parallel. Considering intense laser beams and the strong field asymptotic we explore essentially the multi-photon dynamics. The asymmetry exhibits some non-monotonic behavior depending on initial kinematic conditions; it depends sensitively on the laser pulse duration. Our results provide additional knowledge for studying non-linear multi-photon effects in quantum electrodynamics and may be used in planning experiments in upcoming laser facilities.

A holographic model of probe quarkonia is presented, where the dynamical gravity-dilaton background is adjusted to the thermodynamics of 2 +1 flavor QCD with physical quark masses. The quarkonia action is modified to account for a systematic study of the heavy-quark mass dependence. We focus on the J/ψ and Υ spectral functions and relate our model to heavy quarkonia formation as a special aspect of hadron phenomenology in heavy-ion collisions at LHC.

The lifetime of tungsten (W) monoblocks under fusion conditions is ambivalent. In this work, the microstructure dependent mechanical behaviour of pulsed high heat flux (HHF) exposed W monoblock is investigated. Two different microstructural states, i.e. initial (deformed) and recrystallized, both machined from HHF exposed monoblocks are tested using tensile and small punch tests. The initial microstructural state reveals a higher fraction of low angle boundaries along with a preferred orientation of crystals. Following HHF exposure, the recrystallized state exhibits weakening of initial texture along with a higher fraction of high angle boundaries. Irrespective of the testing methodology, both the microstructural states display brittle failure for temperatures lower than 400∘C. For higher temperatures (>400∘C), the recrystallized microstructure exhibits more ductile behaviour as compared to the initial state. The observed microstructural state-dependent mechanical behaviour is further discussed in terms of different microstructural features. The estimated brittle-to-ductile transition temperature (BDTT) range is noticed to be lower for the recrystallized state as compared to the initial state. The lower BDTT in the recrystallized state is attributed to the high purity of the W in combination with its low defect density, thereby preventing segregation of impurities at the recrystallized boundaries and the related premature failure. Based on this observation, it is concluded that the common opinion of the aggravation of BDTT in W due to recrystallization is not unerring, and as a matter of fact, recrystallization in W could be instrumental for preventing the self-castellation of the monoblocks.

Uranium mining and milling activities raise environmental concerns due to the release of radioactive and other toxic elements. Their long-term management thus requires a knowledge of past events coupled with a good understanding of the geochemical mechanisms regulating the mobility of residual radionuclides. This article presents the results on the traces of anthropic activity linked to previous uranium (U) mining activities in the vicinity of the Rophin tailings storage site (Puy de Dôme, France). Several complementary approaches were developed based on a study of the site's history and records, as well as on a radiological and chemical characterization of soil cores and a dendrochronology. Gamma survey measurements of the wetland downstream of the Rophin site revealed a level of 1050 nSv.h−1. Soil cores extracted in the wetland showed U concentrations of up to 1855 mg.kg−1, which appears to be associated with the presence of a whitish silt loam (WSL) soil layer located below an organic topsoil layer. Records, corroborated by prior aerial photographs and analyses of 137Cs and 14C activities, suggest the discharge of U mineral particles while the site was being operated. Moreover, lead isotope ratios indicate that contamination in the WSL layer can be discriminated by a larger contribution of radiogenic lead to total lead. The dendroanalysis correlate U emissions from Rophin with the site's history. Oak tree rings located downstream of the site contain uranium concentrations ten times higher than values measured on unaffected trees. Moreover, the highest U concentrations were recorded not only for the operating period, but more surprisingly for the recent site renovations as well. This integrated approach corroborates that U mineral particles were initially transported as mineral particles in Rophin's watershed and that amajority of the deposited uranium appears to have been trapped in the topsoil layer, with high organic matter content.

Color centers in silicon carbide (SiC) are promising candidates for quantum technologies. However, the richness of the poly-type and defect coniguration of SiC makes the accurate control of the types and position of defects in SiC still challenging. In this study, helium ion-implanted 4H–SiC was characterized by atomic force microscopy (AFM), confocal photoluminescence (PL), and Raman spectroscopy at room temperature. PL signals of silicon vacancy were found and analyzed using 638-nm and 785-nm laser excitation by means of depth proiling and SWIFT mapping. Lattice defects (C–C bond) were detected by continuous laser excitation at 532 nm and 638 nm, respectively. PL/Raman depth proiling is helpful in revealing the three-dimensional distribution of produced defects. Diferences in the depth proiling results and SRIM simulation results were explained by considering the depth resolution of the confocal measurement setup, helium bubbles, as well as swelling.

We observe third-harmonic generation (THG) in boron-doped silicon (Si:B) upon pumping with picosecond 1.56 THz pulses from a free-electon laser with a peak electric field strength of up to 12 kV/cm. The measurements are performed at cryogenic temperatures where the majority of holes are bound to the acceptor dopants. The dependence of the THG on the pump intensity exhibits a threshold-free power-law behavior with an exponent close to 4. The observations can be explained by THz emission by free holes accelerated in the non-parabolic valence band, under the assumption that the density of free holes increases with the pump intensity. A quantitative treatment supports that these carriers are generated by impact ionization, initiated by the population of thermally ionized carriers , as opposed to direct tunneling ionization. In addition, we also observe intracavity THG by embedding the Si:B in a one-dimensional photonic crystal cavity. The THG efficiency is increased by a factor of eight due to the field enhancement in the cavity, with the potential to reach a factor of more than 100 for pump pulses with a spectrum narrower than the linewidth of the cavity resonance.

Recent astronomical data have provided the primordial deuterium abundance with percent pre- cision. As a result, Big Bang nucleosynthesis may provide a constraint on the universal baryon to photon ratio that is as precise as, but independent from, analyses of the cosmic microwave back- ground. However, such a constraint requires that the nuclear reaction rates governing the production and destruction of primordial deuterium are sufficiently well known.
Here, a new measurement of the 2H(p,γ)3He cross section is reported. This nuclear reaction dominates the error on the predicted Big Bang deuterium abundance. A proton beam of 400- 1650keV beam energy was incident on solid titanium deuteride targets, and the emitted γ-rays were detected in two high-purity germanium detectors at angles of 55◦ and 90◦, respectively. The deuterium content of the targets has been obtained in situ by the 2H(3He,p)4He reaction and offline using the Elastic Recoil Detection method.
The astrophysical S-factor has been determined at center of mass energies between 265 and 1094 keV, addressing the uppermost part of the relevant energy range for Big Bang nucleosynthesis and complementary to ongoing work at lower energies. The new data support a higher S-factor at Big Bang temperatures than previously assumed, reducing the predicted deuterium abundance.

Safe disposal of radioactive waste is one of the big challenges of modern society. The concept of final storage in deep geological formations has become internationally accepted as a means of safe waste management waste in order to isolate it from the Biosphere for hundreds of thousands of years. The safety case has hence to prove that migration from the disposal site into the Biosphere can be effectively prevented across this time span. The potential migration is primarily controlled by sorption/desorption processes onto mineral surfaces along the migration path. Clay minerals are major constituents in both the engineered barriers and in the argillaceous host rock formations being considered for the deep high-level radioactive waste (HLW) repository in Switzerland. Therefore it is critically important to develop an understanding of the uptake processes of radionuclides on clay minerals and other minerals under a wide range of relevant geochemical conditions, to quantify and characterize them with the aim of strengthening the confidence in the safety case. An overview of the work performed at the Laboratory for Waste Management on the retention of radionuclides on clay rich materials will be presented.

The inducible isoenzyme cyclooxygenase-2 (COX-2) is an important hub in cellular signaling, which contributes to tumor progression by modulating and enhancing a pro-inflammatory tu-mor microenvironment, tumor growth, apoptosis resistance, angiogenesis, and metastasis. In order to understand the role of COX-2 expression in melanoma, we investigated the effect of functional knockout of COX-2 in A2058 human melanoma cells. COX-2 knockout was validated by western blot and flow cytometry analysis. When comparing COX-2 knockout cells to con-trols, we observed significantly reduced invasion, colony and spheroid formation potential in cell monolayers and three-dimensional models in vitro, and significantly reduced tumor devel-opment in xenograft mouse models in vivo. Moreover, COX-2 knockout alters the metabolic ac-tivity of cells under normoxia and experimental hypoxia as demonstrated by using the radio-tracers [18F]FDG and [18F]FMISO. Finally, a pilot protein array analysis in COX-2 knockout cells verified significantly altered downstream signaling pathways that can be linked to cellular and molecular mechanisms of cancer metastasis closely related to the enzyme. Given the complexity of the signaling pathways and the multifaceted role of COX-2, targeted suppression of COX-2 in melanoma cells, in combination with modulation of related signaling pathways, appears to be a promising therapeutic approach.

Poly- and single-crystalline samples of In0.670.33In2S4 thiospinel were obtained by various powder metallurgical and chemical vapor transport methods, respectively. All synthesized samples contained β-In0.670.33In2S4 modification only, independent from synthesis procedure. High-resolution powder X-ray diffraction (PXRD) experiment at 80 K enabled observation of split tetragonal reflections (completely overlapped at room temperature), which proves the correctness of crystal structure model accepted for β-polymorph. Combined single-crystal XRD, transmission electron microscopy and selected-area electron diffraction confirmed the presence of three twin domains in as-grown crystals. High temperature PXRD study revealed both abrupt (in full width at half maximum) and gradual (in intensity of satellites, c/a ratio and unit-cell volume) changes in the vicinity of the α-β phase transition. On the other hand, clear thermal effect in heat capacity, magnitude of enthalpy/entropy change and temperature dependence of electrical resistivity, associated with hysteresis, hinted towards the 1st order type of the transition. Two scenarios, based on Rietveld refinement analysis, were proposed for the description of crystal structure evolution from β- to α-modification. Seebeck coefficient, electrical resistivity and thermal conductivity were shown to be influenced not only by phase transition, but also by annealing conditions (S-poor or S-rich atmosphere). Theoretical density functional calculations predicted n-type semiconducting behavior of In0.670.33In2S4, as well as instability of fictitious InIn2S4 thiospinel.

We report on acoustically driven spin resonances in atomic-scale centers in silicon carbide at room temperature. Specifically, we use a surface acoustic wave cavity to selectively address spin transitions with magnetic quantum number differences of 1 and 2 in the absence of external microwave electromagnetic fields. These spin-acoustic resonances reveal a nontrivial dependence on the static magnetic field orientation, which is attributed to the intrinsic symmetry of the acoustic fields combined with the peculiar properties of a half-integer spin system. We develop a microscopic model of the spin-acoustic interaction, which describes our experimental data without fitting parameters. Furthermore, we predict that traveling surface waves lead to a chiral spin-acoustic resonance that changes upon magnetic field inversion. These results establish silicon carbide as a highly promising hybrid platform for on-chip spin-optomechanical quantum control enabling engineered interactions at room temperature.

Open-cell ceramic foams are promising materials in the field of microwave heating. They can be manufactured from susceptor materials and can, therefore, be used as selective heating elements. In this study, the complex permittivities of ceramic foam materials, including silicon-infiltrated silicon carbide (SiSiC), pressureless sintered silicon carbide (SSiC), silicate bonded silicon carbide (SBSiC), and cordierite were determined. The dielectric properties of the foams were determined by the cavity perturbation technique using a TE104 WR340 waveguide resonator at 2.45 GHz. Samples were preheated in a tubular furnace, enabling temperature-dependent permittivity measurements up to 200 °C. The effective dielectric constant and effective loss factor were found to depend on the porosity and material composition of the foam. The SiSiC material had a higher effective dielectric constant than the SSiC and SBSiC ceramics. The effective dielectric constant of the foams showed a trend of gradual increase with increasing temperature. Some selected dielectric mixing relations were then applied to describe the effective permittivity of the foams and compare them with predictions from finite element simulations performed using the CST Studio Suite. The foam morphologies and simple block inclusions were used in the simulations.

Auto-oscillations of magnetization driven by direct spin current have been previously observed in multiple quasi-zero-dimensional (0D) ferromagnetic systems such as nanomagnets and nanocontacts. Recently, it was shown that pure spin Hall current can excite coherent auto-oscillatory dynamics in quasi-one-dimensional (1D) ferromagnetic nanowires but not in quasi-two-dimensional (2D) ferromagnetic films. Here we study the 1D to 2D dimensional crossover of current-driven magnetization dynamics in wire-based Pt/Ni80Fe20 bilayer spin Hall oscillators via varying the wire width.We find that increasing the wire width results in an increase of the number of excited auto-oscillatory modes accompanied by a decrease of the amplitude and coherence of each mode. We also observe a crossover from a hard to a soft onset of the auto-oscillations with increasing wire width. The amplitude of auto-oscillations rapidly decreases with increasing temperature suggesting that interactions of the phase-coherent auto-oscillatory modes with incoherent thermal magnons play an important role in suppression of the auto-oscillatory dynamics. Our measurements set the upper limit on the dimensions of an individual spin Hall oscillator and elucidate the mechanisms leading to suppression of coherent auto-oscillations with increasing oscillator size.

Focused Ion Beam (FIB) is a modern tool for µm and sub-µm structure fabrication and analysis. Commercial systems work mostly with a Gallium - Liquid Metal Ion Source (LMIS) and can achieve a resolution lower than 10 nm and current densities more than 10 Acm-2. The use of alloy LMIS, mainly developed at HZDR, opens a broad field of new applications. In combination with modern FIB systems, like the VELION (Raith) the application field can be extended due to a broad spectrum of available ion species in high resolution ion beams and the stage properties. All these aspects will be concentrated to the ZIM project GRANT No.-ZF4330902 DF7 dealing with the prospective modern topic of nano-magnetic structures from basic research up to new applications. Main topics are: i) the local modification of magnetic single nano-structures using a FIB with Co, Ni, Fe, … ions and ii) the fabrication and investigation of magnonic crystals, made by writing FIB implantation with rare earth ions (Nd, Dy, Ho, Er, …).

In metallurgical processing, non-metallic inclusions in metallic materials are one highly relevant challenge. Bubble injection into molten metals boosts the inclusion control and removal, thus enhancing metal homogenisation and purification. Although this principle of bubble flotation has been used for a long time, the effects of bubble-inclusion interactions in molten metals are not yet well researched. Imaging measurements of multiphase metal flows are challenging for two main reasons: the metals’ high melting temperatures, and their opaqueness for visible light. This work focuses on X-ray and neutron radiographic experiments employing low-melting gallium alloys laden with model particles smaller than 1 mm in diameter. Both, bubbles and particles, are visualised simultaneously with high spatial and temporal resolution to analyse their motions by tracking algorithms. We demonstrate the capability of time-resolved X-ray and neutron radiography to image multiphase flows in particle-laden optically opaque liquid metal, thus contributing to pave the way for systematic investigations on bubble-inclusion interactions in molten metals.

A bremsstrahlung radiation hard x-ray source, produced by a picosecond intense laser irradiated solid target, was used to diagnose an implosion capsule at stagnation phase via Compton radiography in experiments. By performing Monte Carlo and particle-in-cell simulation, we investigated the influence of target materials and laser intensity on the >70 keV bremsstrahlung hard x-ray emission. We found that the brightness of the hard x-rays is proportional to the atomic number multiplied by area density (ZρL), which indicates that the higher Z and higher density gold or uranium material will produce the brightest hard x-rays source at the same thickness. In relativistic laser solid interactions, hot electron recirculation plays an important role in hard x-ray emission. Without recirculation, hard x-ray conversion efficiency decays when increasing the laser intensity. While the hard x-ray emission comes to the maximal saturated conversion efficiency at relativistic laser intensity if considering the electron recirculation.
These results provide valuable insights into the experimental design of Compton radiography

In preclinical cancer research, three-dimensional (3D) cell culture systems such as multicellular spheroids and organoids are becoming increasingly important. They provide valuable information before studies on animal models begin and, in some cases, are even suitable for reducing or replacing animal experiments. Furthermore, they recapitulate microtumors, metastases and the tumor microenvironment much better than monolayer culture systems could. 3D models show higher structural complexity and diverse cell interactions, while reflecting (patho)physiological phenomena such as oxygen and nutrient gradients in the course of their growth or development. These interactions and properties are of great importance for understanding the pathophysiological importance of stromal cells and the extracellular matrix for tumor progression, treatment response or resistance mechanisms of solid tumors. Special emphasis is placed on co-cultivation with tumor-associated cells, which further increases the predictive value of 3D models, e.g. for drug development. The aim of this overview is to shed light on selected 3D models and their advantages and disadvantages, especially from the radiopharmacist´s point of view with focus on the suitability of 3D models for the radiopharmacological characterization of novel radiotracers and radiotherapeutics. Special attention is paid to pancreatic ductal adenocarcinoma (PDAC), as predestined target for the development of new radionuclide-based theranostics.

Background: Detailed information on the low-lying dipole response in atomic nuclei along isotonic or isotopic chains is well suited to systematically investigate the structure and evolution of the Pygmy Dipole Resonance (PDR). Moreover, the dipole strength below and around the neutron separation energy Sn has impact on statistical model calculations for nucleosynthesis processes. Purpose: The photon strength function (PSF) of 87 Rb, which is directly connected to the photoabsorption cross section, is a crucial input for statistical model calculations constraining the Maxwellian-averaged cross section (MACS) of the neutron capture of the unstable s-process branching-point nucleus 86 Rb. Within this work, the photoabsorption cross section is investigated.
Methods: The photoabsorption cross section of the N = 50 nucleus 87 Rb was determined from photon-scattering experiments via the Nuclear Resonance Fluorescence (NRF) technique. Bremsstrahlung beams at the γELBE facility in conjunction with monoenergetic photon beams at the HIGS facility were used to determine the integrated cross sections Is of isolated states as well as the averaged cross section as function of the excitation energy. Decays to the ground state were disentangled from decays to first low-lying excited states. Statistical and experimental approaches for the γ-decay properties at various excitation energies were applied. The linearly polarized photon beams at HIGS provide information on the ratio of electric and magnetic type of radiation.
Results: Within this work, more than 200 ground-state decays and associated levels in ⁸⁷Rb were identified. Moreover, transitions below the sensitivity limit of the state-by-state analysis were taken into account via a statistical approach from the bremsstrahlung data as well as model-independently from the HIGS data. The photoabsorption cross sections at various excitation energies were determined. The dipole response between 6 and 10 MeV of 87 Rb is in agreement with assuming contributions of electric multipolarity, only.
Conclusions: The photoabsorption cross section of ⁸⁷Rb does not contradict with the trend of decreasing E1 strength with increasing proton number along the N = 50 isotonic chain but might also be associated with a constant trend. The experimental γ decay at various excitation energies of the HIGS data supports the statistical approach but does not provide a stringent proof due to the limited sensitivity in the decay channels. The additional E1 strength observed in the present experiments significantly enhances the MACSs compared to recent microscopic D1M HFB+QRPA calculations only. Moreover, theoretical estimations provided by the KADoN iS project could be significantly improved.

After the Chernobyl and Fukushima incidents it has become clear that fungi can take up and accumulate large quantities of radionuclides and heavy metals, but the underlying processes are not well understood yet. For this study, the molecular interactions of uranium(VI) with the white-rot fungi, Schizophyllum commune and Pleurotus ostreatus, and the soil-living fungus, Leucoagaricus naucinus, were investigated. First, the uranium concentration in the biomass was determined by time-dependent bioassociation experiments. To characterize the molecular interactions, uranium was localized in the biomass by transmission electron microscopy analysis. Second, the formed uranyl complexes in both biomass and supernatant were determined by fluorescence spectroscopy. Additionally, possible bioligands in the supernatant were identified. The results show that the discernible interactions between metals and fungi are similar, namely biosorption, accumulation, and subsequent crystallization. But at the same time, the underlying biochemical mechanisms are different and specific to the fungal species. In addition, Schizophyllum commune was found to be the only fungus that, under the chosen experimental conditions, released tryptophan and other indole derivatives in the presence of uranium(VI) as determined by nuclear magnetic resonance spectroscopy. These released substances most likely act as messenger molecules rather than serving the direct detoxification of uranium(VI).

Many phenomena described in relativistic quantum field theory are inaccessible to direct observations, but analogue processes studied under well-defined laboratory conditions can present an alternative perspective. Recently, we demonstrated an analogy of particle creation using an intrinsically robust motional mode of two trapped atomic ions. Here, we substantially extend our classical control techniques by implementing machine-learning strategies in our platform and, consequently, increase the accessible parameter regime. As a proof of methodology, we present experimental results of multiple quenches and parametric modulation of an unprotected motional mode of a single ion, demonstrating the increased level of real-time control. In combination with previous results, we enable future experiments that may yield entanglement generation using a process in analogy to Hawking radiation. This article is part of a discussion meeting issue 'The next generation of analogue gravity experiments'.

Purpose

[18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) parameters have shown prognostic value in nasopharyngeal carcinomas (NPC), mostly in monocenter studies. The aim of this study was to assess the prognostic impact of standard and novel PET parameters in a multicenter cohort of patients.
Methods

The established PET parameters metabolic tumor volume (MTV), total lesion glycolysis (TLG) and maximal standardized uptake value (SUVmax) as well as the novel parameter tumor asphericity (ASP) were evaluated in a retrospective multicenter cohort of 114 NPC patients with FDG-PET staging, treated with (chemo)radiation at 8 international institutions. Uni- and multivariable Cox regression and Kaplan-Meier analysis with respect to overall survival (OS), event-free survival (EFS), distant metastases-free survival (FFDM), and locoregional control (LRC) was performed for clinical and PET parameters.
Results

When analyzing metric PET parameters, ASP showed a significant association with EFS (p = 0.035) and a trend for OS (p = 0.058). MTV was significantly associated with EFS (p = 0.026), OS (p = 0.008) and LRC (p = 0.012) and TLG with LRC (p = 0.019). TLG and MTV showed a very high correlation (Spearman’s rho = 0.95), therefore TLG was subesequently not further analysed. Optimal cutoff values for defining high and low risk groups were determined by maximization of the p-value in univariate Cox regression considering all possible cutoff values. Generation of stable cutoff values was feasible for MTV (p<0.001), ASP (p = 0.023) and combination of both (MTV+ASP = occurrence of one or both risk factors, p<0.001) for OS and for MTV regarding the endpoints OS (p<0.001) and LRC (p<0.001). In multivariable Cox (age >55 years + one binarized PET parameter), MTV >11.1ml (hazard ratio (HR): 3.57, p<0.001) and ASP > 14.4% (HR: 3.2, p = 0.031) remained prognostic for OS. MTV additionally remained prognostic for LRC (HR: 4.86 p<0.001) and EFS (HR: 2.51 p = 0.004). Bootstrapping analyses showed that a combination of high MTV and ASP improved prognostic value for OS compared to each single variable significantly (p = 0.005 and p = 0.04, respectively). When using the cohort from China (n = 57 patients) for establishment of prognostic parameters and all other patients for validation (n = 57 patients), MTV could be successfully validated as prognostic parameter regarding OS, EFS and LRC (all p-values <0.05 for both cohorts).
Conclusions

In this analysis, PET parameters were associated with outcome of NPC patients. MTV showed a robust association with OS, EFS and LRC. Our data suggest that combination of MTV and ASP may potentially further improve the risk stratification of NPC patients.

The granitic pegmatites of the Tørdal area in southern Norway have been known for their Sc enrichment for about 100 years. Scandium is a compatible element in garnet. In this study, 32 garnet samples from 16 pegmatite localities across the Tørdal pegmatite field were investigated to determine the Sc distribution within garnets (crystal scale), within pegmatite bodies (pegmatite scale) and across the Tørdal pegmatite field (regional scale). In the Tørdal pegmatites, Sc content in garnet is representative for the Sc bulk composition of pegmatites, defining garnet as a reliable pathfinder mineral for the exploration of Sc mineralization in pegmatite fields. Garnets with highest Sc concentrations of up to 2197 µg/g have a spessartine component ranging from 50 to 60 mol.%. Since most garnets crystallized during the early stage of pegmatite formation (wall zone stage) Sc decreases in the remaining pegmatite melt, as documented by generally decreasing Sc from core to rim of crystals and by the occurrence of late-stage garnets (albite zone stage) with low Sc. Thus, with progressing crystallization Sc decreases in the melt. The regional Sc distribution in the Tørdal pegmatite field revealed that the Skardsfjell-Heftetjern-Høydalen pegmatites have highest Sc enrichments to sub-economic levels, with an average bulk Sc content of 53 µg/g and an average Sc content in garnet of about 1900 µg/g in the Heftetjern 2 pegmatite.
The assumed resources of the Skardsfjell-Heftetjern-Høydalen area are about 125,000 t ore grading c. 50 µg/g Sc resulting in a total of 625 t Sc, which is too small to have economic potential. However, the strong Sc enrichment of the Tørdal pegmatites is unusual for granitic pegmatites, making them a specific Sc deposit type. The amphibolitic host rocks of the Tørdal pegmatites are identified as the source rocks of Sc. The host rocks, which are part of the Nissedal Outlier supracrustals, are enriched in Sc (mean 34 µg/g) compared to average crustal compositions (mean 14 µg/g). Scandium of amphiboles was preferentially released at the onset of partial melting of the amphibolites. Thus, the Sc content in the pegmatite is strongly dependent on the degree of partial melting.

The mesoscopic scale is usually used to realize the dynamics calculation on a larger spatial scale and time scale. However, there have been few dynamic simulation calculations attempted on the mesoscopic scale for coal flotation systems. In this study, based on the Martini force field, the Coarse-Grain (CG) models of coal, dodecane, and water were established, and the dynamics simulations were performed to study the collector droplet spreading at the coal-water interface. The CG dynamics simulations results showed that the interaction between dodecane and coal was a spontaneous process, and dodecane existed as a collector at the coal-water interface. The radial distribution function of dodecane around coal and water indicated that dodecane was more likely to be distributed around the coal, and as far away as possible from the water. The CG dynamics simulations also revealed the specific spreading stages of the dodecane droplet. The dodecane drop first moved in the form of droplets to the coal-water interface in the aqueous phase. Then at the coal-water interface, the circular droplet broke its shape and spread rapidly on the coal surface through the dodecane CG molecules. Finally, the dodecane CG molecules penetrated deeper into the coal surface layer and formed a dynamic and stable oil film. This provided a good attempt and reference for studying the spreading of collector droplets on the coal-water interface.

A challenge in cancer research is the definition of reproducible, reliable, and practical models, which reflect the effects of complex treatment modalities and the heterogeneous response of patients. Proton beam radiotherapy (PBRT), relative to conventional photon-based radiotherapy, offers the potential for iso-effective tumor control, while protecting the normal tissue surrounding the tumor. However, the effects of PBRT on the tumor microenvironment and the interplay with newly developed chemo-and immunotherapeutic approaches are still open for investigation. This work evaluated thin-cut tumor slice cultures (TSC) of head and neck cancer and organotypic brain slice cultures (OBSC) of adult mice brain, regarding their relevance for translational radiooncology research. TSC and OBSC were treated with PBRT and investigated for cell survival with a lactate dehydrogenase (LDH) assay, DNA repair via the DNA double strand break marker γH2AX, as well as histology with regards to morphology. Adult OBSC failed to be an appropriate model for radiobiological research questions. However, histological analysis of TSC showed DNA damage and tumor morphological results, comparable to known in vivo and in vitro data, making them a promising model to study novel treatment approaches in patient-derived xenografts or primary tumor material.

We report observations of coherent optical transition radiation interferometry (COTRI) patterns generated by microbunched∼200-MeV electrons as they emerge from a laser-driven plasma accelerator. The divergence of the microbunched portion of electrons, deduced by comparison to a COTRI model, is ∼9× smaller than the ∼3 mrad ensemble beam divergence, while the radius of the microbunched beam, obtained from COTR images on the same shot, is <3 μm. The combined results show that the microbunched distribution has estimated transverse normalized emittance∼0.4mm mrad.

Two-dimensional (2D) materials with nanometer-size holes are promising systems for DNA sequencing, water purification, and molecule selection/separation. However, controllable creation of holes with uniform sizes and shapes is still a challenge, especially when the 2D material consists of several atomic layers as, e.g., MoS2, the archetypical transition metal dichalcogenide.We use analytical potential molecular dynamics simulations to study the response of 2D MoS2tocluster irradiation. We model both freestanding and supported sheets and assess the amount of damage created in MoS2by the impacts of noble gas clusters in a wide range of cluster energies and incident angles. We show that cluster irradiation can be used to produce uniform holes in 2DMoS2with the diameter being dependent on cluster size and energy. Energetic clusters can also beused to displace sulfur atoms preferentially from either top or bottom layers of S atoms in MoS2and also clean the surface of MoS2sheets from adsorbents. Our results for MoS2, which should be relevant to other 2D transition metal dichalcogenides, suggest new routes toward cluster beam engineering of devices based on 2Dinorganic materials.

D rilling is a key task in exploration campaigns to characterize mineral deposits at depth. Drillcores are first logged in the field by a geologist and with regards to, e.g., mineral assemblages, alteration patterns, and structural features. The core-logging information is then used to locate and target the important ore accumulations and select representative samples that are further analyzed by laboratory measurements (e.g., Scanning Electron Microscopy (SEM), Xray diffraction (XRD), X-ray Fluorescence (XRF)). However, core-logging is a laborious task and subject to the expertise of the geologist. Hyperspectral imaging is a non invasive and non-destructive technique that is increasingly being used to support the geologist in the analysis of drill-core samples. Nonetheless, the benefit and impact of using hyperspectral data depend on the applied methods. With this in mind, machine learning techniques, which have been applied in different research fields, provide useful tools for an advance and more automatic analysis of the data. Lately, machine learning frameworks are also being implemented for mapping minerals in drill-core hyperspectral data. In this context, this work follows an approach to map minerals on drill-core hyperspectral data using supervised machine learning techniques, in which SEM data, integrated with the mineral liberation analysis (MLA) software, are used in training a classifier. More specifically, the high-resolution mineralogical data obtained by SEM-MLA analysis is resampled and co-registered to the hyperspectral data to generate a training set. Due to the large difference in spatial resolution between the SEM-MLA and hyperspectral images, a pre-labeling strategy is required to link these two images at the hyperspectral data spatial resolution. In this study, we use the SEM-MLA image to compute the abundances of minerals for each hyperspectral pixel in the corresponding SEM-MLA region. We then use the abundances as features in a clustering procedure to generate the training labels. In the final step, the generated training set is fed into a supervised classification technique for the mineral mapping over a large area of a drill-core. The experiments are carried out on a visible to near-infrared (VNIR) and shortwave infrared (SWIR) hyperspectral data set and based on preliminary tests the mineral mapping task improves significantly.

Mineral mapping is an important task in exploration campaigns where it is required to obtain a preliminary idea about the composition of ore deposits. Hyperspectral imaging is becoming a trending technology within the mining community to map minerals during exploration campaigns. This is because minerals have unique spectral responses in specific parts of the electromagnetic spectrum. These responses depend on the bonds between the atoms and electron orbitals of the minerals. In other words, based on the molecular vibrations and composition of the minerals the light reflects differently from the minerals and therefore, the spectral responses vary. In general, alteration minerals (e.g., phyllosilicates) can be mapped using the visible to near-infrared (VNIR) and short-wave infrared (SWIR) parts of the electromagnetic spectrum, whereas rock-forming minerals, (e.g., feldspars and quartz) are better distinguishable using the long-wave infrared (LWIR). Therefore, fusing the VNIR-SWIR and LWIR parts of the electromagnetic spectrum provides a complete range of data for the mineral mapping task. The benefit of using hyperspectral data from both regions of the electromagnetic spectrum to map minerals is clear and it has been previously implemented in an independent manner. However, in this work, we focus on different machine learning strategies to fuse VNIR-SWIR and LWIR hyperspectral data for an accurate mineral mapping. We test two fusion scenarios: feature level fusion and decision-level fusion. For the feature-level fusion, we adopt a state-of-the-art multiple feature learning technique to adequately exploit the information containing in both data types. Hence, we take advantage of the complementary information using only one classifier. For the decision-level fusion, we integrate the independent classification results obtained using the VNIR-SWIR and LWIR data. In this way, higher robustness is expected from the combination of the classification results. The experiments are carried out on real hyperspectral datasets of drill core samples. With this contribution, we introduce a novel approach for the mining community to map minerals using a full range of hyperspectral data where not only alteration minerals but rock-forming minerals can be jointly mapped. Moreover, our proposed approach can accurately map minerals with weak spectral responses in both wavelength ranges. Based on preliminary attempts, the fusion of the VNIRSWIR and LWIR at both decision and feature levels performed better than considering both datasets independently.

A multi-label classification concept is introduced for the mineral mapping task in drill-core hyperspectral data analysis. As opposed to traditional classification methods, this approach has the advantage of considering the different mineral mixtures present in each pixel. For the multi-label classification, the well-known Classifier Chain method (CC) is implemented using the Random Forest (RF) algorithm as the base classifier. High resolution mineralogical data obtained from Scanning Electron Microscopy (SEM) instrument equipped with the Mineral Liberation Analysis (MLA) software are used for generating the training data set. The drillcore hyperspectral data used in this paper cover the visible-near infrared (VNIR) and the short-wave infrared (SWIR) range of the electromagnetic spectrum. The quantitative and qualitative analysis of the obtained results shows that the multi-label classification approach provides meaningful and descriptive mineral maps and outperforms the single-label RF classification for the mineral
mapping task.