Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

GeSn alloys hold great promise as high-performance, low-cost, near- and short-wavelength infrared photodetectors with the potential to replace the relatively expensive and currently market-dominant InGaAs- and InSb-based photodetectors. In this Letter, we demonstrate room-temperature GeSn pn photodetectors fabricated by a complementary metal-oxide-semiconductor compatible process, involving Sn and P ion implantation and flash-lamp annealing prior to device fabrication. The fabrication process enables the alloying of Ge with Sn at concentrations up to 4.5% while maintaining the high-quality single-crystalline structure of the material. This allows us to create Ge0.955Sn0.045 pn photodetec-tors with a low dark current density of 12.8 mA/cm2 and a relatively high extended responsivity of 0.56 A/W at 1.71 l m. These results pave the way for the implementation of a cost-effective, scalable, and CMOS-compatible short-wavelength infrared detector technology.

Using the external field method, {\it i.e.\/} evaluating the effective action $V_{\mathrm{eff}}$ for an arbitrarily strong constant and homogeneous field, we explore nonperturbative properties of QED allowing arbitrary gyromagnetic ratio $g$. We find a cusp at $g = 2$ in: a) The QED $b_0$-renormalization group coefficient, and in the infinite wavelength limit in b) a subclass containing the pseudoscalar ${\cal P}^{2n}= (\vec E\cdot\vec B)^{2n} $ of light-light scattering coefficients. Properties of $b_0$ imply for certain domains of $g$ asymptotic freedom in an Abelian theory.

We study the impact of axions or axion-like particles on birefringent (i.e., polarization changing) scattering of x-ray photons at the Coulomb field of nuclei superimposed by optical lasers of ultra-high intensity. Applying the specifications of the Helmholtz International Beamline for Extreme Fields (HIBEF), we find that this set-up can be more sensitive than previous experiments such as PVLAS in a large domain of parameter space. Furthermore, by changing the pump and probe laser orientations and frequencies, one can scan different axion masses.

We implement a longstanding proposal by Weisskopf to apply virtual polarization corrections to
the in/out external fields in study of the Euler-Heisenberg-Schwinger effective action. Our approach
requires distinguishing the electromagnetic and polarization fields based on mathematical tools
developed by Bia lynicki-Birula, originally for the Born-Infeld action. Our solution is expressed
as a differential equation where the one-loop effective action serves as input. As a first result of
our approach, we recover the higher-order one-cut reducible loop diagrams discovered by Gies and
Karbstein.

We investigate the lane formation in nonequilibrium systems of colloidal particles moving in
parallel that are driven by the force of gravity. For this setup, an experimental implementation of a channel on a slope can be conceptualized. We employ the Brownian dynamics algorithm and confine the repulsive particles with hard walls based on the solution of the Smoluchowski equation in the half space. A difference of the driving force acting on the colloids could be achieved by using two spherical particle types with differing diameters but equal mass density. Firstly, we investigate how a difference in the channel slope affects the lane formation of the systems, after which we analyze the lanes that formed. We found that the large particles push the small particles to the walls, resulting in exclusively small particle lanes at the walls. This contrasts the equilibrium state, where depletion forces push the larger particles to the walls. Additionally, we have a closer look at the mechanisms by which the lanes form. Finally, we found system parameter values that foster lane formation to lay the foundation for an experimental realization of our proposed setup. To round this off, we give an exemplary calculation of the slope angle needed to get the experimental system into a state of lane order. With the examination of lane order in systems that are driven in parallel, we hope to deepen our understanding of nonequilibrium order phenomena.

Nonlinear phenomena in the THz spectral domain are important for the understanding of optoelectronic properties of quantum systems and provide a basis for modern information technologies. Here, we report a giant THz nonlinearity in high-mobility 2D topological insulators based on HgTe quantum wells, which manifests itself in a highly efficient third harmonic generation. We observe a third harmonic THz susceptibility several times higher than in bare graphene and many orders of magnitude higher than in trivial quantum well structures based on other materials. To explain the strong nonlinearity of HgTe-based heterostructures at the THz frequencies, we consider the acceleration of free carriers with high mobility and variable dispersion. This acceleration model, for which the non-parabolicity of the band dispersion is key, in combination with independently measured scattering time and conductivity is in good agreement with our experimental data in a wide temperature range for THz fields below the saturation. Our approach provides a route to material engineering for THz applications based on frequency conversion.

On May 9, 2023, the Helmholtz Open Science Office organized the Forum "Research Evaluation, Reputation Systems, and Openness". On this occasion, experts from Helmholtz and the scientific community presented current developments in the field of research evaluation and reflected on the connection between reputation systems and openness. The event focused on three main topics: 1) Development of Helmholtz quality indicators for data and software products, 2) 10 years Declaration on Research Assessment (DORA) and 3) Coalition for Advancing Research Assessment (CoARA). A central subject in the discussion and presentations was the issue of the use and definitions of indicators which foster Open Science. The discussion centered on what appropriate incentives look like in order to make research evaluation fair and appreciative. Furthermore, the relevance of these questions from the perspective of early-career scientists was highlighted.

Genetic frontotemporal dementia is most commonly attributable to mutations in the C9orf72, GRN, or MAPT genes. The disease has near-complete penetrance, making presymptomatic carriers an ideal population for ascertaining the earliest changes in disease progression and the identification of suitable biomarkers for designing therapeutic trials when minimal neuronal loss has occurred. Cerebral perfusion, as measured by arterial spin labelling (ASL) MRI, has shown promise in being one such biomarker. However, longitudinal profiles of change in perfusion over time in presymptomatic carriers across all three genetic subgroups are lacking.
Using data from the multicenter GENetic Frontotemporal dementia Initiative, we investigated longitudinal profiles of cerebral perfusion using ASL-MRI in C9orf72 (n = 42), GRN (n = 70), and MAPT (n = 31) presymptomatic mutation carriers and non-carrier controls (n = 158). ASL and T1w scans were processed with the ExploreASL pipeline to produce partial volume corrected perfusion images, which were parcellated to extract mean perfusion values from whole brain grey matter and regions defined by the second version of the automated anatomical atlas (AAL2). Linear mixed effects models were used to assess longitudinal perfusion change.
Mutation carrier groups and non-carriers were statistically indistinguishable by baseline demographic and clinical measures. Decline in whole brain grey matter perfusion over time was more pronounced in all three carrier subgroups relative to controls, with changes most pronounced in GRN, followed by C9orf72 and MAPT variants. Additionally, GRN and MAPT groups featured global grey matter hypoperfusion relative to non-carrier controls as early as one year after baseline measurement, with C9orf72 featuring significant hypoperfusion after two years. Region of interest analysis demonstrated that each genetic subgroup had its own regional profile in terms of longitudinal perfusion decline. Perfusion decline in C9orf72 was localized around the frontal lobe and subcortical structures with a slight right-hemispheric bias. GRN featured a more widespread perfusion decline, with notable asymmetry featuring a stronger left hemisphere involvement. Significant decline in perfusion in MAPT was limited to the thalamus, which was a region that was significant in all three mutation carrier groups. Cerebral blood flow relative to baseline measurements had declined to a greater extent in converter individuals versus presymptomatic carriers who were past their expected year of disease onset within specific frontal regions of the brain.
These results provide additional evidence that cerebral perfusion is a potential biomarker for assessment of genetic FTD and its genetic subgroups at the prodromal stage of the disease.

Multiphase computational fluid dynamics (CFD) simulation is a useful tool to study the hydrodynamics in a bubble column if
appropriate closure models are known. Systematic assessment of different models is an ongoing venture that benefits from
improved validation data. The present study accumulates a database on two-phase flow experiments in a bubble column.
This is achieved by using a combination of particle image velocimetry and shadowgraphy to measure the liquid velocity field
and gas dispersion properties simultaneously. This methodology is applied for different needle diameters and gas flow rates.
The experimental data are compared with CFD simulations which show good predictions. A systematic investigation of the
three-phase flow in the bubble column will appear as a sequel.

Immune checkpoint inhibitor therapy targeting the PD-1/PD-L1 axis in cancer patients holds promise as an oncological treatment. However, the number of non-responders remains high. Consequently, clinicians need a diagnostic tool to predict treatment outcomes. PET imaging can play an important role in supporting therapy decisions by offering whole-body scan while quantitatively assessing PD-L1 expression. In multi-step organic synthesis, four PD-L1 radiolig-ands containing a linker-chelator system for radiometallation, along with three hydrophilizing units – one sulfonic acid and two phosphonic acids – were synthesized. After labeling with 64Cu, log D7.4 values of below –3.03 were determined and proteolytic stability studies were conducted confirming stabilities over 94% after 48 hours. Binding affinities studies were conducted using two different binding assays revealing high affinities up 13 nM. µPET/CT imaging was performed in tumor-bearing mice to investigate PD-L1 specific tumor uptake and the pharmacokinetic profile. The µPET images revealed an unexpected in vivo behavior, including low tumor uptake in PD-L1 positive tumors, high liver uptake, and accumulation in bone/bone marrow/joints. These effects were attributed to Ca2+-affinity and/or binding to macrophages. Despite phosphonic acids offering a high degree of water-solubility, their incorporation must be carefully considered to avoid ex-acerbating the radioligands’ pharmacokinetic behaviors.

We report on electron beam collimation using a passive plasma lens, integrated directly and conveniently into a laser wakefield accelerator stage operating in the high charge regime. The lens is created by reshaping the gas density profile of a super-sonic jet at the beam's exit side through an obstacle mounted above the jet. It reduces the beam's divergence by a factor of two to below 1 mrad (root-mean-square), while preserving the total charge of 170 pC and maintaining the energy spread. The resulting spectral-charge density, here defined as the charge per energy bandwidth and emission angle, of up to 7 pC/(MeV·mrad) played a key role in the recent experimental demonstration of free-electron lasing. The presented simple and robust gas shaping technique holds the potential to generate specific density profiles, essential for the application of adiabatic focusing or staging of accelerators.

Hydrogen at extreme temperatures and pressures is ubiquitous throughout our universe and naturally occurs in a variety of astrophysical objects. In addition, it is of key relevance for cutting-edge technological applications, with inertial confinement fusion research being a prime example. In the present work, we present exact \emph{ab initio} path integral Monte Carlo (PIMC) results for the electronic density of warm dense hydrogen along a line of constant degeneracy across a broad range of densities. Using the well-known concept of reduced density gradients, we develop a new framework to identify the breaking of bound states due to pressure ionization in bulk hydrogen. Moreover, we use our PIMC results as a reference to rigorously assess the accuracy of a variety of exchange--correlation (XC) functionals in density functional theory calculations for different density regions. Here a key finding is the importance of thermal XC effects for the accurate description of density gradients in high-energy density systems. Our exact PIMC test set is freely available online and can be used to guide the development of new methodologies for the simulation of warm dense matter and beyond.

Although it is known that a loss in separation performance is caused by liquid maldistribution, there is only marginal knowledge about liquid distribution in rotating packed beds (RPBs). As a result, the exact influence of liquid distribution on separation performance in RPBs is not fully understood. Therefore, this study focuses on the influence of different liquid distributors on the liquid distribution of a rotating metal foam packing inside RPBs. Liquid hold-ups were measured non-invasively using gamma-ray computed tomography (CT), and water/air was the system under investigation, operated at atmospheric pressure, temperature of 20°C, liquid flow rate of 60 l h^-1, F-factor of 2.3 Pa^0.5 and at rotational speeds up to 900 rpm. For the first time, the liquid distribution in axial direction of a rotating metal foam of an RPB could be accessed, which allowed the identification and quantification of occurring wall flows. Furthermore, the path of the liquid phase through the entire opaque packing could be visualized for different operating conditions by synchronizing the CT scans with the rotational speed of the rotor. The use of a single-point full-jet nozzle was more prone to cause wall flow than the use of a rotating baffle distributor with 36 baffles. For comparison, circumferential liquid maldistribution was also observed using a rotating baffle distributor with 12 baffles.

The SPEChpc™ 2021 suites are application-based benchmarks de-
signed to measure performance of modern HPC systems. The bench-
marks support MPI, MPI+OpenMP, MPI+OpenMP target offload,
MPI+OpenACC and are portable across all major HPC platforms.

With the development of advanced biomedical theragnosis and bioengineering tools, smart and soft responsive microstructures and nanostructures have emerged. These structures can transform their body shape on demand and convert external power into mechanical actions. Here, we survey the key advances in the design of responsive polymer−particle nanocomposites that led to the development of smart shapemorphing microscale robotic devices. We overview the technological roadmap of the field and highlight the emerging opportunities in programming magnetically responsive nanomaterials in polymeric matrixes, as magnetic materials offer a rich spectrum of properties that can be encoded with various magnetization information. The use
of magnetic fields as a tether-free control can easily penetrate biological tissues. With the advances in nanotechnology and manufacturing techniques, microrobotic devices can be realized with the desired magnetic reconfigurability. We emphasize that future fabrication techniques will be the key to bridging the gaps between integrating sophisticated functionalities of
nanoscale materials and reducing the complexity and footprints of microscale intelligent robots.

Silicon layers with a selenium impurity concentration up to 1021 cm–3, which exceeds the equilibrium solubility limit of this
impurity in silicon by four orders of magnitude, were obtained by high-dose ion implantation followed by pulsed laser
annealing at pulse energy densities from 0.5 to 2.5 J/cm2. Rutherford backscattering of He+ ions showed that up to 70% of
the implemented impurity atoms were localized at silicon crystal-lattice sites after laser annealing. The Se-hyperdoped Si
layers were characterized by increased (up to 45–55%) absorption in the spectral range 1100–2400 nm. Thermal treatment
(550°C for 30 min followed by 850°C for 5 min) did not increase the IR absorption as compared with the initial Si, which was
explained by Se losses resulting from diffusional redistribution. Recrystallization of Si layers amorphized by Se ions and
redistribution of the dopant with equilibrium thermal treatment were theoretically evaluated.

This work demonstrates the novel concept of a mixed-dimensional reconfigurable field effect transistor (RFET) by combining a one-dimensional (1D) channel material such as a silicon (Si) nanowire with a two-dimensional (2D) material as a gate dielectric. An RFET is an innovative device that can be dynamically programmed to perform as either an n- or p-FET by applying appropriate gate potentials. In this work, an insulating 2D material, hexagonal boron nitride (hBN), is introduced as a gate dielectric and encapsulation layer around the nanowire in place of a thermally grown or atomic-layer-deposited oxide. hBN flake was mechanically exfoliated and transferred onto a silicon nanowire-based RFET device using the dry viscoelastic stamping transfer technique. The thickness of the hBN flakes was investigated by atomic force microscopy and transmission electron microscopy. The ambipolar transfer characteristics of the Si-hBN RFETs with different gating architectures showed a significant improvement in the device’s electrical parameters due to the encapsulation and passivation of the nanowire with the hBN flake. Both n- and p-type characteristics measured through the top gate exhibited a reduction of hysteresis by 10–20 V and an increase in the on–off ratio (ION/IOFF) by 1 order of magnitude (up to 108) compared to the values measured for unpassivated nanowire. Specifically, the hBN encapsulation provided improved electrostatic top gate coupling, which is reflected in the enhanced subthreshold swing values of the devices. For a single nanowire, an improvement up to 0.97 and 0.5 V/dec in the n- and p-conduction, respectively, is observed. Due to their dynamic switching and polarity control, RFETs boast great potential in reducing the device count, lowering power consumption, and playing a crucial role in advanced electronic circuitry. The concept of mixed-dimensional RFET could further strengthen its functionality, opening up new pathways for future electronics.

During pandemics like COVID-19, both the quality and quantity of services offered by businesses and organizations have been severely impacted. They often have applied a hybrid home office setup to overcome this problem, although in some situations, working from home lowers employee productivity. So, increasing the rate of presence in the office is frequently desired from the manager's standpoint. On the other hand, as the virus spreads through interpersonal contact, the risk of infection increases when workplace occupancy rises.
Motivated by this trade-off, in this paper, we model this problem as a bi-objective optimization problem and propose a practical approach to find the trade-off solutions. We present a new probabilistic framework to compute the expected number of infected employees for a setting of the influential parameters, such as the incidence level in the neighborhood of the company, transmission rate of the virus, number of employees, rate of vaccination, testing frequency, and rate of contacts among the employees. The results show a wide range of trade-offs between the expected number of infections and productivity, for example, from 1 to 6 weekly infections in 100 employees and a productivity level of 65\% to 85\%. This depends on the configuration of influential parameters and the occupancy level.
We implement the model and the algorithm and perform several experiments with different settings of the parameters. Moreover, we developed an online application based on the result in this paper which can be used as a recommender for the optimal rate of occupancy in companies/workplaces.

The new benchmark for VVER-1000 control rod ejection transient was published recently. One of the assumptions proposed in the benchmark is given fixed values for fuel-cladding gas gap thermal conductivity and thermo-physical properties of fuel and cladding materials. In this paper, authors investigate an impact of this assumption on simulation results.

Unraveling the metal sources of Zn-Pb deposits is vital to understand the genetic types and ore-forming processes. The Sichuan-Yunnan-Guizhou metallogenic province (SYGMP) hosts abundant Zn-Pb deposits that are variably rich in critical metals such as Ga, Ge, Cd and Tl. However, sources of these critical metals and main metal Zn are still unclear. The Liangyan Cd-rich Zn-Pb deposit as a representative in the SYGMP is hosted in a carbonate sedimentary sequence and controlled by the regional Yadu-Wogong anticline and Yadu-Mangdong thrust fault. SZn-Cd isotopes of sulfide minerals from this deposit are obtained in order to understand the sources of metals and origin of the deposit. Sulfur isotopic results of pyrite and sphalerite reveal that sulfur was produced by thermochemical sulfate reduction (TSR) of sulfates from the Carboniferous dolostone and mudstone and the Ediacaran-Devonian carbonates. Sphalerite grains have δ66ZnJMC values that are negatively correlated with the δ114Cd spex values, implying different sources for both Zn and Cd. The variation trend of δ66ZnJMC and Cd/Zn
suggests that Zn was mainly sourced from the Neoproterozoic basement with minor from the Carboniferous wallrocks. Besides, sphalerite grains show a negative correlation between δ114Cdspex and Zn/Cd, and these values fall in the field close to the Carboniferous carbonates, but away from the Permian Emeishan basalts, indicating that Cd was derived mainly from the Carboniferous wallrocks with minor from the Emeishan basalts. Together with geological evidence, the multi-isotope data suggest that the Liangyan deposit belongs to a thrust-controlled MVT Zn-Pb deposit.

Following several previous European projects (EFR, CP-ESFR and ESFR-SMART), a new project ESFR-SIMPLE has been proposed in response to the HORIZON-EURATOM call on “Safety of advanced and innovative nuclear designs and fuels”. The new project aims at challenging the Generation IV ESFR (European Sodium Fast Reactor) designed in the ESFR-SMART project, to improve its safety and economics thanks to innovative technologies. The project high-level objectives and actions are: 1) Challenge the ESFR design to simplify the reactor, through reducing its size, which could allow taking advantage of SMRs (Small Modular Reactors) in terms of transportability, modularization, standardization, flexible operation and machine learning, all ultimately leading to improved economics. 2) Propose, develop and assess advanced methods of monitoring and processing operational data using Artificial Intelligence, e.g., to optimize fault detection in the steam generators at an early stage. 3) Produce new experimental data in order to support calibration and validation of the computational tools such as properties measurements of irradiated and non-irradiated MOX fuel including fuel with optimized micro-structures, and to assist in qualification of innovative components, such as expansion bellows, thermo-electric pumps and accident tolerant core-catcher. 4) Assess alternative technologies, such as the use of metallic fuel and compact secondary system design, for the large-size ESFR to improve the economics and safety. 5) Ensure that the knowledge generated in the project will be shared not only among the project partner institutions, but also among as wide a range of stakeholders as possible in Europe and internationally. The project relies on a consortium of 16 partners and will benefit from different skills and experiments available in Europe and in the US. It started in October 2022 and will end in September 2026. In addition to the technical details, this paper also briefly outlines the organization of the project.

The rate of the final step in the astrophysical αp process, the 34Ar(α,p)37K reaction, suffers from large uncertainties due to a lack of experimental data, despite having a considerable impact on the observable light curves of x-ray bursts and the composition of the ashes of hydrogen and helium burning on accreting neutron stars. We present the first direct measurement constraining the 34Ar(α,p)37K reaction cross section, using the Jet Experiments in Nuclear Structure and Astrophysics gas jet target. The combined cross section for the 34Ar,Cl(α,p)37K,Ar reaction is found to agree well with Hauser-Feshbach predictions. The 34Ar(α,2p)36Ar cross section, which can be exclusively attributed to the 34Ar beam component, also agrees to within the typical uncertainties quoted for statistical models. This indicates the applicability of the statistical model for predicting astrophysical (α,p) reaction rates in this part of the αp process, in contrast to earlier findings from indirect reaction studies indicating orders-of-magnitude discrepancies. This removes a significant uncertainty in models of hydrogen and helium burning on accreting neutron stars.

Artificial intelligence (AI) is proliferating and developing faster than any domain scientist can adapt. To support the scientific enterprise in the Helmholtz association, a network of AI specialists has been set up to disseminate AI expertise as an infrastructure among domain scientists. As this effort exposes an evolutionary step in science organization in Germany, this article aspires to describe our setup, goals, and motivations. We comment on past experiences, current developments, and future ideas as we bring our expertise as an infrastructure closer to scientists across our organization. We hope that this offers a brief yet insightful view of our activities as well as inspiration for other science organizations.

Background:

Decreased cerebral blood flow (CBF) and deterioration of blood-brain barrier (BBB) are suggested to be precursor conditions of cognitive impairment. Using a novel multi-echo-time arterial spin labelling (ASL) protocol, we examined the time of exchange (Tex) of water across the BBB as a measurement of BBB permeability. We further examined the association of cardiovascular risk factors with Tex in an ongoing cohort study.
Method:
Data (n=29, mean age: 55.9±6.1years, 69% women) were drawn from Neurological biomarkers of Blood, MRI and Cognition (NEURO-BMC) study performed at National University of Singapore. NEURO-BMC is an ongoing prospective cohort study (age: 45-65 years) on brain changes in a subclinical phase of cognitive impairment. A multi-echo, Hadamard-encoded multi-post-labelling-delay pseudo-continuous ASL (PCASL) protocol was used on a 3T scanner. ExploreASL was used with a modified version of FSL FABBER(4) to quantify cerebral blood flow (CBF), arterial transit time (ATT), and Tex. ASL-extracted parameters were compared with cardiovascular risk parameters such as blood pressure (BP), BMI and smoking status.
Result:
High systolic and diastolic BP were associated with significantly reduced Tex (Fig 1). Additionally, higher systolic and diastolic BP showed a trend of increased ATT and reduced CBF, though the associations were not statistically significant (Table 1). High BMI had a significant association with increased ATT and reduced CBF. However, no trend was observed between BMI and Tex. Participants who ever smoked were observed to have a reduced Tex and CBF and increased ATT, but statistical significance was only found for CBF (Fig 1).
Conclusion:
In this pilot study, we showed that BBB-ASL-derived parameters - ATT, CBF, and Tex - were associated with BP, BMI, and smoking status. While the sample size for this preliminary analysis was too small to make a definitive conclusion as not all associations were statistically significant, all studied cardiovascular risk factors showed their potential in increasing the risk of BBB deterioration. Further investigation with a larger sample size and other health risk factors to assess these observations is warranted.

Structural insight into nano-objects down to the atomic scale is one of the most important prerequisites in understanding functional materials properties and will ultimately permit to relate the size and shape of nanoparticles to their catalytic activity. We elucidate the potential of extracting structural information about a small ensemble of nanoparticles semi-regularly arranged on a periodic array from coherent X-ray Bragg diffraction. The observed superstructure in the Pt(111) Bragg peak obviously originates from the mutual interference of the Bragg scattered wave field from individual nanoparticles in the nano-array. Despite the absence of a symmetry center in the Bragg peak of the nano-array, we identify the most prominent in-plane spatial frequencies of the latter by applying a Patterson map analysis to the Bragg peak superstructure. Integration along the out-of-plane reciprocal space direction over the relevant in-plane regions of interest results in Laue oscillations that arise from nanoparticle sets of similar heights in real space. A one-to-one comparison with real-space microscopic information obtained from SEM and AFM suggests potential nanoparticle subsets as origin for the X-ray intensity in these regions of interest by the good agreement in their height and direction-dependent in-plane interparticle distances, as also further supported by simulations. Nanoparticle arrays with well-defined tunable sizes and lateral distances may serve in the future to track structural changes of smallest catalysis-relevant nanoparticles during operando heterogeneous catalysis experiments in the 10 nm size regime.

Nowadays, there is a growing interest in the Small Modular Reactors (SMRs) technology due to their enhanced safety level and reasonably reduced manufacturing and construction costs. However, modeling tools should be able to deal with the special features inherent to their design such as the modeling of the helical Steam Generators. In this work, a Steam Line Break sequence in the NuScale reactor has been simulated using several modeling tools based on a full-plant thermohydraulic model for a system code coupled with a 3D nodal diffusion code for describing the core physics. To do so, four different models have been developed by four different organization for the coupled codes TRACE/PARCS, TRACE/PANTHER and ATHLET/DYN3D. In that sense, a very reasonable agreement is reached among the steady-state parameters of the plant computed by each participant and the ones presented in the Design Standard Application Report of NuScale. Regarding the simulation of the SLB transient, it should be noted that after 100 seconds of simulation, it can be said that remarkable differences are to be seen among the results for the time behavior of the core temperatures. Those differences are attributable to differences in the heat transfer within the helically coiled steam generators. Important differences have been also found in the decay heat removal system performance, so it is concluded that further investigation and model development is needed for the phenomena occurring in the steam generators and the decay heat removal heat system.

Deformable image registration (DIR) is a versatile tool used in many applications in radiotherapy (RT). DIR algorithms have been implemented in many commercial treatment planning systems providing accessible and easy-to-use solutions. However, the geometric uncertainty of DIR can be large and difficult to quantify, resulting in barriers to clinical practice. Currently, there is no agreement in the RT community on how to quantify these uncertainties and determine thresholds that distinguish a good DIR result from a poor one. This review summarises the current literature on sources of DIR uncertainties and their impact on RT applications. Recommendations are provided on how to handle these uncertainties for patient-specific use, commissioning, and research. Recommendations are also provided for developers and vendors to help users to understand DIR uncertainties and make the application of DIR in RT safer and more reliable.

This study aimed to verify and validate the transient simulation capability of the hybrid code system RAST-F for fast reactor analysis. For this purpose, control rod (CR) drop experiments of eight CRs and six control groups in the China Experimental Fast Reactor (CEFR) start-up tests were utilized to simulate the CR drop transient. The RAST-F numerical solution, including the neutron population, time-dependent reactivity, and CR worth, was compared against the measurement values obtained from two out-of-core detectors. Moreover, the time-dependent reactivity and CR worth from RAST-F were verified against the results obtained by the Monte Carlo code Serpent using continuous energy nuclear data. A code-to-code comparison between Serpent and RAST-F showed good agreement in terms of time-dependent reactivity and CR worth. The discrepancy was less than 160 pcm for reactivity and less than 110 pcm for CR worth. RAST-F solution was almost identical to the measurement data in terms of neutron population and reactivity. All the calculated CR worth results agreed with experimental results within two standard deviations of experimental uncertainty for all CRs and control groups. This work demonstrates that the RAST-F code system can be a potential tool for analyzing time-dependent phenomena in fast reactors.

Prompt Gamma-ray Spectroscopy (PGS) in conjunction with the Monte Carlo Library Least Squares (MCLLS) approach was investigated for the purposes of range monitoring in proton therapy through Monte Carlo simulations. Prompt gamma-rays are produced during treatment and can be correlated to the range of the proton beam in the tissue. In contrast to established approaches, MCLLS does not rely on the identification of specific photopeaks. Instead it treats each individual constituent as a library spectrum and calculates coefficients for each spectrum, and therefore takes both the photopeaks and the Compton continuum into account. It can thus be applied to organic scintillators traditionally not used for energy spectroscopy due to their low Z number and density. Preliminary results demonstrate that the proposed approach returns a strong linear correlation between the range of the primary proton beam and the calculated library coefficients, depending on the composition of libraries. This can be exploited for range monitoring.

Surface-directed and preferentially oriented assemblies of nanomaterials can enable enhanced applications in e.g. catalysis or sensing. Coordination polymers, which can be even conducting, could be suitable materials for this purpose because of their facile surface anchoring. Hence, we coassembled rhodium paddle-wheel building blocks with bi- or trifunctional linkers in dip coatings that were produced by layer-by-layer approach on silicon wafers functionalized by thin nanocrystalline gold surfaces. These gold surfaces were decorated with a self-assembled monolayer (SAM) for coordination and binding to the Rh-units. As linkers, pyrazine, triazine and melamine were used, leading to rectangularly-shaped, hexagonally-shaped or needle-like crystals, respectively. The coordination polymers were produced by repeated dipping into the linker and paddle-wheel solution, each followed by a cleaning step. The crystals growth was followed by atomic force microscopy (AFM) grazing incidence small-angle X-ray scattering (GISAXS) and grazing incidence wide-angle X-ray scattering (GIWAXS). AFM and GISAXS revealed the shape and size of the crystals. GIWAXS disclosed their preferred orientation. It turned out that the automated dipping procedure does not lead to a strong alignment of crystallites along the dipping direction for the pyrazine-based deposits. However, these crystals are preferentially oriented with respect to the substrate normal direction. The crystallographic direction and the degree of the alignment depend on the number of deposition cycles. In the early phases of the deposition process, predominantly “lying” crystals were detected. With increasing number of the deposition cycles, the fraction of “standing” crystals became dominant. These crystals are oriented with their {010} directions perpendicular to the surface of the substrate. Still, “lying” and some tilted crystals were detected additionally. The study gives a deeper structural understanding of crystallite assemblies and suggests an evolvement of more anisotropic orientations of the crystallites with increasing deposition cycles (leading to the prevalence of crystals having the preferred {010} orientation with respect to the surface normal direction).

Mineral separation processes operate on properties of individual particle, which can currently be quantified with 2D
characterization techniques, namely 2D automated mineralogy. While 2D automated mineralogy data have driven significant
developments in particle-based separation models, this data inherently correspond to 2D slices of 3D objects, which leads to
stereological bias in the quantification of geometric particle properties. X-ray micro-computed tomography (μCT) is a 3D
imaging technique that can quantify particle geometry. However, μCT only collects limited information regarding material
composition, making mineral identification quantification a challenge. To overcome this challenge, we present a workflow
that utilizes individual particle histograms and corrects image artefacts caused by μCT measurements, such as partial
volume effect. We demonstrate the application of the workflow to perform 3D mineral characterisation of a sulfidic gold ore,
where mineral phases that are commonly mistaken with μCT could be distinguished: pyrite and chalcopyrite, gold, and
galena. Results were verified by comparison with inductively coupled plasma mass spectrometry and 2D automated
mineralogy. As a result, the workflow provides the user with a detailed 3D particle dataset containing the modal mineralogy
and surface compositions, size, and geometrical properties of each particle in a sample – essential data for modelling
mineral separation processes.

Room temperature ferromagnetism has been reported in chemical vapor deposition-grown mixed-phase MoS2-MoOx thin films after Xe ion irradiation. Magnetic moment has significantly been enhanced after ion irradiation. Deterioration in crystallinity after ion irradiation has been shown by X-ray diffraction and Raman spectroscopy measurements. The variation in the surface morphology and/or formation of edge states can be observed by secondary electron microscopy images. The reduction in the oxygen vacancy concentration, probed by analysis of the O 1s core level X-ray photoelectron spectrum for the film with the maximum magnetic moment, rules out the possibility of ferromagnetism due to oxygen vacancy. Enhancement in the Mo content in 5+ and 6+ oxidation states due to the occupation of sulfur vacancy sites by oxygen after ion irradiation, calculated from X-ray photoelectron spectroscopy core level of Mo 3d and S 2p and valence band spectra, has been observed. Density functional theory (DFT) calculations also show the one-to-one correspondence of saturation magnetic moment with Mo6+ content. So, the enhancement in the ferromagnetism in mixed-phase of MoS2-MoOx thin films is due to the increase of Mo in 6+ oxidation state and exchange interaction between the different oxidation states of Mo via p-orbital of anion and formation of edged states.

Hybrid waveguides consisting of two-dimensional layered materials pad on the surface of optical waveguides suffer from a nonuniform and loose contact between the two-dimensional material and the waveguide, which can reduce the efficiency of the pulsed laser. Here, we present high-performance passively Q-switched pulsed lasers in three distinct structures of monolayer graphene-Nd:YAG hybrid waveguides irradiated by energetic ions. The ion irradiation enables the monolayer graphene a tight contact and strong coupling with the waveguide. As a result, Q-switched pulsed lasers with narrow pulse width and high repetition rate are obtained in three designed hybrid waveguides. The narrowest pulse width is 43.6 ns, provided by the ion-irradiated Y-branch hybrid waveguide. This study paves the way toward developing on-chip laser sources based on hybrid waveguides by using ion irradiation.

Layered magnetic materials are becoming a major platform for future spin-based applications. Particularly the air-stable van der Waals compound CrSBr is attracting considerable interest due to its prominent magneto-transport and magneto-optical properties. In this work, we observe a transition from antiferromagnetic to ferromagnetic behavior in CrSBr crystals exposed to high-energy, non-magnetic ions. Already at moderate fluences, ion irradiation induces a remanent magnetization with hysteresis adapting to the easy-axis anisotropy of the pristine magnetic order up to a critical temperature of 110 K. Structure analysis of the irradiated crystals in conjunction with density functional theory calculations suggest that the displacement of constituent atoms due to collisions with ions and the formation of interstitials favors ferromagnetic order between the layers.

The sigma2 receptor (TMEM97) expression correlates well with the Ki67 expression in tumours [1, 2] and therefore represents an attractive marker for the proliferative status. We developed the 18F-labelled radioligand [18F]RM273 for sigma2 receptor imaging in brain tumours.
[18F]RM273 (2-[4-(6-[18F]fluoro-1H-pyrrolo[2,3-b]pyridin-1-yl)butyl]-6,7-dimethoxy-1,2,3,4-tetra-hydroisoquinoline) has been obtained by automated synthesis by Cu-mediated oxidative radiofluorination of the aryl boronic acid pinacol ester precursor. Radiometabolite analysis was performed in mouse plasma samples 30 min p.i. The target specificity was investigated by in vitro autoradiographic studies with or without the sigma2 receptor antagonist ISO-1 in rat brain cryosections with a stereotactically implanted F98 glioma [3]. The biodistribution of [18F]RM273 in healthy mice (female, CD1; n = 4; 7.2 ± 1.1 MBq) and the tumour uptake into the F98 glioma (male, Fischer rats; n = 2; 21 and 25 MBq) were investigated by dynamic PET imaging for 60 min (nanoScan®PET-1T MRI, Mediso).
Polar radiometabolites of [18F]RM273 (AM 69 – 233 GBq/μmol, RCY 8%) were detectable in plasma, but not in brain extracts. We determined a 3-times higher density of binding sites in tumour compared to healthy brain in vitro [3]. PET studies revealed a TAC peak value of 1.3 at 2.25 min p.i. followed by a wash out in the brain of healthy mice [3]. In the F98 glioma brain region a two times higher uptake (SUVmean of 0.8–1.3 at 30–60 min p.i.) compared to contralateral was observable. Therefore, [18F]RM273 could potentially be used to determine the proliferative status of brain tumours.
Acknowledgements: This work was supported by the Deutsche Forschungsgemeinschaft (DFG: BR 1360/13-1).
References: [1] Shoghi et al. Plos One 2013, 8: e74188; [2] Yang et al. Molecules 2020, 25 (22): 5439 [3] Moldovan et al. Int. J. Mol. Sci. 2021, 22: 5447

Series of novel ligands with the 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline or 5,6-dimethoxyisoindoline pharmacophore were designed and synthesized for evaluation of their structure-activity relationship to the sigma-2 (2) receptor and development as suitable PET radioligands. Compound 1 was found to possess nanomolar affinity (6.97 nM) for the 2 receptor, high subtype selectivity (58-fold) and high selectivity over 40 other receptors and transporters. Radioligand [18F]1 was prepared with radiochemical yield of 37–54%, > 99% radiochemical purity, molar activity of 107–189 GBq/μmol. Biodistribution and blocking studies in mice and micro-PET/CT imaging of [18F]1 in rats indicated excellent binding specificity of [18F]1 to the 2 receptors in vivo. Micro-PET/CT imaging of [18F]1 in the U87MG glioma xenograft model demonstrated clear tumor visualization with high tumor uptake and tumor-to-background ratio. Co-injection with CM398 (5 mol/kg) led to remarkable reduction of tumor uptake (80%, 60–70 min), indicating high specific binding of [18F]1 in U87MG glioma xenografts.

The long-lived and optically addressable spin states of silicon vacancies (VSi) in 4H-SiC make them promising qubits for quantum communication and sensing. These color centers can be created in both the hexagonal (V1) and in the cubic (V2) local crystallographic environments of the 4H-SiC host. While the spin of the V2 center can be efficiently manipulated by optically detected magnetic resonance at room temperature, spin control of the V1 centers above cryogenic temperatures has been elusive. Here, we show that the dynamic strain of surface acoustic waves can overcome this limitation and efficiently excite magnetic resonances of V1 centers up to room temperature. Based on the width and temperature dependence of the acoustically induced spin resonances, we attribute them to transitions between spin sublevels in the excited state. The acoustic spin control of both V1 and V2 centers in their excited states opens new ways for applications in quantum technologies based on spin-optomechanics.

Numerical Simulation of Particles in Rising Gas Bubbles

Curvilinear magnetism is a framework, which helps understanding the impact of geometrical curvature on complex magnetic responses of curved 1D wires and 2D shells [1-3]. The lack of inversion symmetry and emergence of curvature induced anisotropy and Dzyaloshinskii-Moriya interaction (DMI) stemming from the exchange interaction [4,5] are characteristic of curved surfaces. Recently, a non-local chiral symmetry breaking was discovered [6], which is responsible for the coexistence and coupling of multiple magnetochiral properties within the same magnetic object [7].
Regarding antiferromagnets, it is demonstrated that intrinsically achiral one-dimensional curvilinear antiferromagnets behave as a chiral helimagnet with geometrically tunable DMI, orientation of the Neel vector and the helimagnetic phase transition [8-10]. This positions curvilinear antiferromagnets as a platform for geometrically tunable antiferromagnetic spinorbitronics.

[1] D. Makarov et al., Curvilinear micromagnetism: from fundamentals to applications (Springer, Zurich, 2022).
[2] D. Makarov et al., Adv. Mat. 34, 2101758 (2022).
[3] D. Sheka et al., Small 18, 2105219 (2022).
[4] Y. Gaididei et al., PRL 112, 257203 (2014).
[5] O. Volkov et al., PRL 123, 077201 (2019).
[6] D. Sheka et al., Commun. Phys. 3, 128 (2020).
[7] O. Volkov et al., Nature Com. 14, 1491 (2023).
[8] O. Pylypovskyi et al., Nano Lett. 20, 8157 (2020).
[9] O. Pylypovskyi et al., APL 118, 182405 (2021).
[10] Y. Borysenko et al., PRB 106, 174426 (2022).

Extending 2D structures into 3D space has become a general trend in multiple disciplines, including electronics, photonics, plasmonics, superconductivity and magnetism [1,2]. This approach provides means to modify conventional or to launch novel functionalities by tailoring curvature and 3D shape of magnetic thin films and nanowires [2,3]. In this talk, we will address fundamentals of curvature-induced effects in magnetism and review current application scenarios. In particular, we will demonstrate that curvature allows tailoring fundamental anisotropic and chiral magnetic interactions [4] and enables fundamentally new non-local chiral symmetry breaking effect [5,6]. Application potential of geometrically curved magnetic architectures is currently being explored as mechanically reshapeable magnetic field sensors for automotive applications, memory, spin-wave filters, high-speed racetrack memory devices, magnetic soft robotics [7] as well as on-skin interactive electronics relying on thin films [8,9,10] as well as printed magnetic composites [11,12,13].

[1] P. Gentile et al., Electronic materials with nanoscale curved geometries. Nature Electronics (Review) 5, 551 (2022).
[2] D. Makarov et al., New Dimension in Magnetism and Superconductivity: 3D and Curvilinear Nanoarchitectures. Advanced Materials (Review) 34, 2101758 (2022).
[3] D. Makarov et al., Curvilinear micromagnetism: from fundamentals to applications (Springer, Zurich, 2022).
[4] O. Volkov et al., Experimental observation of exchange-driven chiral effects in curvilinear magnetism. Physical Review Letters 123, 077201 (2019).
[5] D. D. Sheka et al., Nonlocal chiral symmetry breaking in curvilinear magnetic shells. Communications Physics 3, 128 (2020).
[6] O. M. Volkov et al., Chirality coupling in topological magnetic textures with multiple magnetochiral parameters. Nature Communications 14, 1491 (2023).
[7] M. Ha et al., Reconfigurable Magnetic Origami Actuators with On-Board Sensing for Guided Assembly. Advanced Materials 33, 2008751 (2021).
[8] G. S. Canon Bermudez et al., Magnetosensitive e-skins for interactive devices. Advanced Functional Materials (Review) 31, 2007788 (2021).
[9] J. Ge et al., A bimodal soft electronic skin for tactile and touchless interaction in real time. Nature Communications 10, 4405 (2019).
[10] G. S. Canon Bermudez et al., Electronic-skin compasses for geomagnetic field driven artificial magnetoception and interactive electronics. Nature Electronics 1, 589 (2018).
[11] M. Ha et al., Printable and Stretchable Giant Magnetoresistive Sensors for Highly Compliant and Skin-Conformal Electronics. Advanced Materials 33, 2005521 (2021).
[12] E. S. Oliveros Mata et al., Dispenser printed bismuth-based magnetic field sensors with non-saturating large magnetoresistance for touchless interactive surfaces. Adv. Mater. Technol. 7, 2200227 (2022).
[13] R. Xu et al., Self-healable printed magnetic field sensors using alternating magnetic fields. Nature Communications 13, 6587 (2022).

Extending 2D structures into 3D space has become a general trend in multiple disciplines, including electronics, photonics, plasmonics, superconductivity and magnetism [1,2]. This approach provides means to modify conventional or to launch novel functionalities by tailoring curvature and 3D shape of magnetic thin films and nanowires [2,3]. In this talk, we will address fundamentals of curvature-induced effects in magnetism and review current application scenarios. In particular, we will demonstrate that curvature allows tailoring fundamental anisotropic and chiral magnetic interactions [4] and enables fundamentally new non-local chiral symmetry breaking effect [5,6]. Application potential of geometrically curved magnetic architectures is currently being explored as mechanically reshapeable magnetic field sensors for automotive applications, memory, spin-wave filters, high-speed racetrack memory devices as well as on-skin interactive electronics relying on thin films [7,8] as well as printed magnetic composites [9] with appealing self-healing performance [10].

Reference list
[1] P. Gentile et al., Electronic materials with nanoscale curved geometries. Nature Electronics (Review) 5, 551 (2022).
[2] D. Makarov et al., New Dimension in Magnetism and Superconductivity: 3D and Curvilinear Nanoarchitectures. Advanced Materials (Review) 34, 2101758 (2022).
[3] D. Makarov et al., Curvilinear micromagnetism: from fundamentals to applications (Springer, Zurich, 2022).
[4] O. Volkov et al., Experimental observation of exchange-driven chiral effects in curvilinear magnetism. Physical Review Letters 123, 077201 (2019).
[5] D. D. Sheka et al., Nonlocal chiral symmetry breaking in curvilinear magnetic shells. Communications Physics 3, 128 (2020).
[6] O. M. Volkov et al., Chirality coupling in topological magnetic textures with multiple magnetochiral parameters. Nature Communications 14, 1491 (2023).
[7] J. Ge et al., A bimodal soft electronic skin for tactile and touchless interaction in real time. Nature Communications 10, 4405 (2019).
[8] G. S. Canon Bermudez et al., Electronic-skin compasses for geomagnetic field driven artificial magnetoception and interactive electronics. Nature Electronics 1, 589 (2018).
[9] M. Ha et al., Printable and Stretchable Giant Magnetoresistive Sensors for Highly Compliant and Skin-Conformal Electronics. Advanced Materials 33, 2005521 (2021).
[10] R. Xu et al., Self-healable printed magnetic field sensors using alternating magnetic fields. Nature Communications 13, 6587 (2022).

Objectives: Radionuclide availability plays a key role for development of new radiopharmaceuticals. Moreover, theranostic matched pairs of radionuclides have aroused interest in the last couple of years. On the one hand, 68Ga has been used as a diagnostic counterpart to the therapeutic β--emitter 177Lu, however, due to its short half-life (68 min), further alternatives have to be considered. In particular 67Ga (half-life: 3.26 d) as the longest-lived of the radiogallium isotopes has γ-lines that can be used for SPECT imaging (93.3 keV, 184 keV). On the other hand, 67Cu is referred as a theranostic radionuclide due to its β--emission and γ-emission suitable for SPECT, forming a perfect matched pair with the PET radionuclides 61/64Cu. At HZDR the zinc targetry and target chemistry developed for 67Cu production [1] has been applied to produce 67Ga.

Methods: 67Cu production consisted of proton irradiation (16.8 MeV, 60 µA, up to 20 h, 30° solid target configuration) of 70Zn targets (100-140 mg/cm2) electrodeposited onto silver via the 70Zn(p,α)67Cu nuclear reaction. Target work-up comprise a two- or three-step chromatographic column separation [1]. Gamma spectroscopy was used to quantify the radionuclidic purity (RNP), ICP-MS for the molar activity (Am) and test radiolabeling with the macrocyclic complexing agent TETA for apparent molar activity (AMA) quantification. Additionally, 67Ga was produced by proton irradiation (19 MeV, 35 µA, 2 h, 30° solid target configuration) of enriched 68Zn targets (60-70 mg/cm2) electrodeposited onto gold via the 68Zn(p,2n)67Ga nuclear reaction. After “cooling down” of the target (12-16 h, decay of co-produced 68Ga), the radiochemical separation consisted of a two-step chromatographic column separation; first a 1 mL TK400 cartridge followed by a 0.3 mL DGA branched cartridge. RNP was quantified by gamma spectroscopy.

Results: Activity yields of > 1.0 GBq 67Cu at EOB were reached, leading to over 800 MBq [67Cu]CuCl2 at EOP in 1.5 mL of 0.05 M HCl with RNP g.t. 99.5 % (at EOP) and AMA up to 300 GBq/µmol (EOB corrected). Furthermore, activities of up to 1.8 GBq 67Ga at EOB, and ca. 1.0 GBq [67Ga]GaCl3 at EOP in 0.5 mL of 0.05 M HCl were produced. First 67Ga gamma spectroscopy results showed a RNP of over 99 % at EOP. In both cases, the activity reached represented about 60 % to 70 % of the calculated yield.

Conclusions: Production of the radionuclides 67Cu and 67Ga from proton irradiation of zinc targets is being performed at HZDR. Both radionuclide product solutions proved sufficient quality regarding RNP and radiolabeling properties. further optimization of the 67Ga production is planned. Although 67Cu activities produced are not enough for clinical demand, the obtained yields are adequate for first in vitro and in vivo studies while other production routes are being explored.

References:

[1] Brühlmann SA, Walther M, Kreller M, Reissig F, Pietzsch H-J, Knieß T and Kopka K. Pharmaceuticals 2023, 16, 314.

Aim/Introduction: Actinium-225 has gained great importance in Targeted Alpha Therapy (TAT) due to its suitable physical and chemical properties. In past years, studies using 225Ac-PSMA-617 have shown promising results [1], however, the macropa chelator has proven more beneficial properties regarding labelling and stability in vivo as compared with DOTA. While 68Ga has been used for DOTA-based radioconjugates, the macropa chelator lacks an imaging radionuclide counterpart. For this purpose, the β+-emitter 133La is an attractive candidate due to its physical properties and similar to 225Ac coordination chemistry. Following our recent publication [2], further optimization of the production of 133La with high radionuclidic purity (RNP) for theranostic purposes is presented. Materials and Methods: Lanthanum-133 was produced via the 134Ba(p,2n)133La nuclear reaction. Proton irradiation (19 MeV, 35 µA, 30 min) was performed using the HZDR TR-FLEX (ACSI) cyclotron on silver discs filled with 25 mg of [134Ba]BaCO3 capped with a 25 µm aluminum foil. The solid target was opened and the powder dissolved in 2 mL of 1 M HNO3. A one-step separation was carried out with a branched DGA resin cartridge after testing other resins. The 134Ba-containing fractions were collected and recycled through [134Ba]BaCO3 precipitation. Test radiolabelling of macropa-derived PSMA conjugates previously published by our group was performed in the MBq/nmol range [3]. Results: Lanthanum-133 yields of ca. 1.8 GBq for the described targets were reached at end of bombardment (EOB), accounting for about 65 % of the theoretical yield. After radiochemical separation, 1.2 GBq 133La were collected in 1 mL of 0.05 M HCl ready to label, with a RNP over 99.5 %. Further studies showed no detriment of the RNP by 21 MeV proton irradiation, thus being feasible irradiation of larger targets (prior thermal studies). Furthermore, quantitative radiolabeling was achieved with ligand concentrations down to 300 MBq/nmol. Conclusion: Lanthanum-133 of high RNP was produced for the first time. Considering future medical demands, the scale up to radioactivity amounts that are needed for clinical application purposes could be achieved by increasing the irradiation time. Alternatively, irradiation with higher currents or of thicker targets could also lead to higher activities. Based on these results, our group will attempt to establish a diagnostic platform for 225Ac-TAT based on 133La-macropa radioconjugates instead of the conventional 68Ga-DOTA application. References: [1] Kratochwil et al., J. Nucl. Med. 2016, 57, 1941-1944 [2] Brühlmann et al., Pharmaceuticals 2022, 15, 1167. [3] Reissig et al., Cancers 2021, 13, 1974.

Objectives
Copper-67 (half-life 61.83 h, β--emission [mean energy 140 keV], γ-emission [184.6 keV, 48.7 % intensity]), is a promising radiometal due to its theranostic potential. Moreover, it forms a perfect matched pair with the
β+-emitters 61Cu and 64Cu. However, broad application of this radionuclide is limited due to its low availability. In this work, we investigate the no-carrier-added 67Cu production via the 70Zn(p,α)67Cu reaction [1].

Warm dense matter (WDM)---an extreme state that is characterized by extreme densities and temperatures---has emerged as one of the most active frontiers in plasma physics and material science. In nature, WDM occurs in astrophysical objects such as giant planet interiors and brown dwarfs. In addition, WDM is highly important for cutting-edge technological applications such as inertial confinement fusion and the discovery of novel materials. In the laboratory, WDM is studied experimentally in large facilities around the globe, and new techniques have facilitated unprecedented insights. Yet, the interpretation of these experiments requires a reliable diagnostics based on accurate theoretical modeling, which is a notoriously difficult task [1].

In this work, I will give an overview of how we can use exact ab-initio path integral Monte Carlo (PIMC) simulations [2] together with thermal density functional theory (DFT) calculations to get new insights into the behavior of WDM. This includes recent results for various density response properties [3] such as the exchange—correlation (XC) kernel [2,4], and the utility of PIMC reference data to assess the accuracy of different XC functionals [5].

Finally, I will show how switching to the imaginary-time representation allows us to significantly improve the interpretation of X-ray Thomson scattering (XRTS) experiments, which are a key diagnostic for WDM [3]. Specifically, I will present a model-free temperature diagnostic [6] based on the well-known principle of detailed balance, but available for all wave numbers, and a new idea to directly extract the electron—electron static structure factor from an XRTS measurement [7]. As an outlook, I will show how new PIMC capabilities [8] will allow to give us novel insights into electronic correlations in warm dense quantum plasmas, leading to unprecedented agreement between experiments [9] and theory.

[1] M. Bonitz et al., Physics of Plasmas 27, 042710 (2020)
[2] M. Böhme et al., Physical Review Letters 129, 066402 (2022)
[3] T. Dornheim et al., Physics of Plasmas 30, 032705 (2023)
[4] Zh. Moldabekov et al., Journal of Chemical Theory and Computation 19, 1286-1299 (2023)
[5] Zh. Moldabekov et al., arXiv:2308.07916 (submitted)
[6] T. Dornheim et al., Nature Communications 13, 7911 (2022)
[7] T. Dornheim et al., arXiv:2305.15305 (submitted)
[8] T. Dornheim et al., arXiv:2308.06071 (submitted)
[9] T. Döppner et al., Nature 618, 270-275 (2023)

Objectives:

Targeted Alpha Therapy (TAT) is a research field of highest interest in specialized molecular radionuclide therapy. In particular, the radionuclide actinium-225 provides all necessary physical and chemical properties for a successful clinical application. Although the macropa chelator has shown beneficial properties regarding labelling and stability in vivo as compared with DOTA, the former lacks an imaging radionuclide counterpart to 225Ac. In this connection, lanthanum is an appropriate surrogate for actinium due to its comparable coordination chemistry. Furthermore, the imaging properties of the β+-emitter lanthanum-133 makes it an attractive candidate as a theranostic matched pair to 225Ac. Following our recent publication [1], 133La of high radionuclide purity for theranostic purposes was produced through the 134Ba(p,2n)133La reaction.

Objectives.
Copper-67 (67Cu, half-life 61.83 h, β--emission [mean energy 140 keV], γ-emission [184.6 keV with 48.7 % intensity, i.a.]), is a promising radiometal due to its theranostic potential. While 61Cu and 64Cu are suitable for PET, matched pair 67Cu brings a therapeutic counterpart to the table. However, broad application of this radionuclide is limited due to its low availability. No-carrier-added 67Cu can be produced through the 70Zn(p,α)67Cu reaction, while featuring a low yield and the need of expensive 70Zn target material. Nevertheless, co-production of other copper nuclides (from other zinc isotopes low-content) as well as contamination with stable copper can be minimized but not completely eliminated.

The gas flow modulation technique (GFM) is a novel non-invasive approach for measuring the axial gas dispersion coefficient in bubble columns. The approach overcomes the limitations of traditional tracer-based techniques, qualifying it as a promising candidate for measurements in an industrial setting. The current work elaborates systematic guidelines for selecting the experimental parameters for the GFM. These guidelines are crucial for its successful application. In addition, a novel approach is proposed for confidently extracting the values and the uncertainty limits of the axial gas dispersion coefficient. Afterwards, we show the application of these guidelines in the frame of a case study that serves the purpose to illustrate their application and to demonstrate their usefulness.