Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

The dipole strength of the N=28 nuclide ⁵⁴Fe was studied in photon-scattering experiments using bremsstrahlung produced with electron beams of energies of 7.5 and 13.9 MeV at the gELBE facility as well as using quasi-monoenergetic and linearly polarized photon beams of 26 energies within the range from 5.5 to 11.4 MeV at the HIgS facility. About 100 J=1 states were identified, out of them 19 with 1⁺ and 30 with 1^- assignment. The quasicontinuum of unresolved transitions was included in the analysis of the spectra and the intensities of branching transitions were estimated on the basis of simulations of statistical γ-ray cascades. As a result, the photoabsorpton cross section up to the neutron-separation energy was determined and compared with predictions of statistical reaction codes. The experimental M1 strengths from resolved 1⁺ states are compared with results of large-scale shell-model calculations.

The THEREDA project [1] aims at providing an extensive thermodynamic database for the modeling of solubility equilibria in aqueous solutions within the context of nuclear waste disposal. Focus is laid on saline solutions, typically with an ionic strength > 1M, using the Pitzer approach [2].
THEREDA is operated by five research institutions. A web-based user interface is used for data capture and documentation. The primary products, however, are ready-to-use data files for PHREEQC, Geochemist’s Workbench, CHEMAPP, and (to a limited extent) EQ3/6. In addition, a code-independent, generic format (JSON) is available for download. Before release, data sets are subject to rigid, internal checks. More than 200 test calculations are used to continously ensure the correctness of calculated results, both in terms of earlier test runs and between different codes.
While extending the database, experimental data for various chemical systems are recorded. The agreement with model calculations using THEREDA are documented. This “positive list” is continously being extended.
In response to the limited lifetime of existing codes and to extend our user base, efforts are undertaken to support two additional codes, GEMS and TOUGHREACT.

[1] H. C. Moog et al. (2015): Appl. Geochem. (55) 72-84. http://dx.doi.org/10.1016/j.apgeochem.2014.12.016.
[2] K. S. Pitzer (1991): Activity Coefficients in Electrolyte Solutions (2nd ed.). CRC Press, ISBN 0-8493-5415-3.

Resource and energy efficiency are essential for the raw-materials industry to secure a sufficient and economically feasible supply of minerals and metals for society in the coming decades. This task becomes more challenging as the complexity of primary resources increases. Mineral processing plant control systems, an important tool for guaranteeing efficient plant operations, are currently based on processing models that only consider bulk chemical and physical properties. They do not incorporate particle-level data – a significant limitation when dealing with complex bulk materials. This contribution presents a novel particle-based prediction model capable of dealing with complete particle datasets (i.e. no dimensionality reduction required), of operating without human-input and able to provide the probability of each particle in a system to deport to any one of the material streams within a given operation. The method is applicable to any processing unit that does not modify the physical dimensions of particles, such as comminution.
The particle-based prediction model consists of a regularized logistic regression model with a probability adjustment step to accommodate geological variability. Even though the method supports different types of particle-level characterization data, it is built around data obtained by scanning electron microscope-based image analysis. Constructed cases demonstrate the method’s efficiency in recreating characteristic recovery trends for magnetic separation, hydrocyclone and flotation units. In addition, the system is used to reconstruct a complete processing plant with three flotation and one magnetic separation circuits. Predicted results of masses and compositions for all of the intermediates and products correspond well to the results reported from the plant itself. The provided probabilities allow for the modelling of the interaction between particle properties and machine parameters, and can later be used for process simulation and optimization.

We present a status update of the PEnELOPE laser system currently under construction at the Helmholtz-Zentrum Dresden-Rossendorf. We show the first energetic activation of the first major amplification stage on the 10 Joule-level in order to benchmark the performance of the whole last two amplifier sections and the progress at the last amplifier section in order to achieve a first activation.

The microstructure and texture evolution of a metastable Ti-5Al-3V-3Mo-2Cr-2Zr-1Nb-1Fe alloy during bar-rolling and after various thermal treatments was investigated by high-energy synchrotron diffraction and electron backscatter diffraction. Bar-rolling is applied in the (α+β)-phase field in order to achieve a bi-modal (duplex) microstructure. The effect of dynamic recrystallized and recovered zones on texture of Ti5321was analyzed separately, as well as the texture of primary α-precipitates and secondary α-lamellae. The texture of the recovered zones is characterized by a cube component ({001}<100>) plus α- and γ-fibre with dominant {100}<110>, {112}<110>, {111}<110> components, while the texture of the recrystallized zones is a strong cube texture. After aging or recrystallization plus aging, this texture component remains, while it disappears after solution treatment. The primary α-precipitates have their c-axes perpendicular to the rolling direction and do not follow the Burgers orientation relationship. This texture characteristics remains after various thermal heat treatments. Secondary α-lamellae obey the Burgers orientation relationship. Moreover, a variant selection of secondary α-lamellae occurs. The mechanism of texture formation of the β-phase and the precipitation behavior of the α-phase is discussed.
The hardness increase can be attributed to size, shape and volume fraction of the α-precipitates.
Different combinations of primary α- and secondary α-precipitates make an increase in hardness of about 11%.

Recent years have shown that particle therapy offers highly conformal brain irradiation and optimized healthy tissue sparing. Nevertheless, elevated dose levels in healthy tissue, particularly in the distal beam region, can lead to undesirable long-term side effects. The biological mechanisms of such effects, however, remain unclear. A major obstacle towards correlating effects on clinical and cellular imaging levels is the mapping of radiation dose to specific brain regions or individual cell populations.
We present a publicly available dataset of registered, multimodal imaging data of nine mice that received proton brain irradiation of different doses in a clinically relevant setting. It is available open access (https://rodare.hzdr.de/record/801) and comprises a baseline computed tomography (CT) scan, simulated distributions of dose and linear energy transfer, a co-aligned mouse brain atlas as well as magnetic resonance imaging (MRI) follow-up of up to six months. Additionally, we provide registered histological brain sections with eight histological stainings, reflecting all major cell types in adult mice brains. We used the self-developed tool Slice2Volume together with existing methods (Elastix & Big Warp) to fuse image data. The software is available open source: https://github.com/jo-mueller/Slice2Volume
The provided image data spans several orders of magnitude of scale. Images of all modalities can be freely overlaid for every mouse as is demonstrated on Figure 1. This, for instance, allows tracing MRI image changes to specific cell populations. Hence, the dataset enables direct correlations and mechanistic observations regarding effects of proton radiation on the anatomical (atlas), clinical (MRI) and microscopic level (histology).

This editorial presents three comprehensive reviews of recent preclinical and clinical findings supporting the healing of critical bone defects through adjuvant therapy approaches, which have been published in a special issue. In summary, these articles highlight current concepts that attempt to improve osteogenesis and bone healing using small molecule drugs and intelligent drug delivery methods. The main conclusions lead to an evaluation of the modulation of angiogenesis and microcirculation as a very promising concept. The modulation of inflammation, on the other hand, was evaluated as critical with respect to the start and duration of therapy. Novel solutions are expected from a targeted modulation of bone metabolism, the use of bifunctional or hybrid compounds, appropriate drug combinations and delivery systems.

Purpose:

To develop a computer-driven and thus less user dependent method, allowing for a simple and straight forward generation of a Monte Carlo (MC) beam model of a scanned proton and carbon ion beam delivery system.

Methods:

The method was applied on five different clinical as well as one research beam lines for proton and carbon ions of three different particle therapy centers using synchrotron or cyclotron accelerator systems: i) MedAustron ion therapy center, ii) University Proton Therapy Dresden, and iii) Center Antoine Lacassagne Nice. In a first step, experimental measurements were performed for proton and carbon ion energies in the available energy ranges. Data included depth dose profiles measured in water and spot sizes in air at various iso-center distances.
Using an automated regularization-based optimization process, GATE/Geant4 beam models of the respective beam lines were generated and compared to independent measurements. Sequentially, using least square weighting functions with and without regularization, the beam parameters energy, energy spread, beam sigma, divergence, and emittance were iteratively tuned until a user defined agreement was reached. Based on the parameter tuning for a set of energies a beam model was generated. The resulting beam models were validated for all centers comparing laterally integrated depth dose curves and spot sizes in air. For a representative center, 3D dose cubes were measured and compared to simulations.

Results: Beam ranges in the MC beam models agreed on average within 0.2 mm compared to measurements for all energies and beam lines. Spot sizes (full-width at half maximum) at all positions in air, differed by less than 0.4% from the measurements.
Dose calculation with the beam model for the MedAustron clinical beam line agreed better than 1.7% in absolute dose for a representative clinical case treated with protons.
For protons, beam model generation, including geometry creation, data conversion, and validation, was possible within three working days.The number of iterations required for the optimization process to converge, was found to be similar for all beam line geometries and particle types.

Conclusion:

The presented method was demonstrated to work independently of the beam optics behavior of the different beam lines, particle types and geometries. Furthermore, it is suitable for non-expert users and requires only limited user interaction. Beam model validation for different beam lines based on different beam delivery systems, showed good agreement.

Ion irradiations are indispensable for exploring radiation effects on materials, for example, radiation hardening. However, the extraction of radiation hardening as function of displacement damage from the nanoindentation (NI) response of self-ion-irradiated metallic alloys is a challenge. In particular, recent attempts suffer from interference with contributions arising from injected self-interstitial atoms. Moreover, instances of available microstructural evidence and NI results reported for the same material and same irradiation are rare. In order to tackle these issues, the depth-dependent irradiated microstructure and the NI response were analyzed for Fe-9Cr and oxide dispersion strengthened Fe-Cr alloys irradiated with 5 MeV iron ions. Cross-sectional transmission electron microscopy indicated the appearance of irradiation-induced dislocation loops but no other types of visible microstructural changes. NI indicated maxima of the radiation hardening as function of contact depth. Links between the depth-resolved primary radiation damage, the observed depth-dependent characteristics of loops and the measured hardening are considered. As a key point, the link between loops and hardening requires the integration of the local hardening contributions over the indentation plastic zone. Calculations and measurements are compared with respect to both the depth position of maximum hardening and the substrate effect. The role of the model assumptions is discussed with special emphasis on the plastic zone size and the superposition of hardening contributions. The latter is found to be material-specific. The model also allows hardening contributions arising from displacement damage and injected interstitials to be separated.

Flüssigmetallbatterien bieten die Möglichkeit, große Mengen elektrischer Energie zu Speichern und bieten durch ihre Masse und ihr Temperaturniveau ebenfalls ein gewisses Potential zur Speicerung thermischer Energie. Der Vortrag stellt die Technologie und die Forschung am HZDR sowie einzelne Ergebnisse zur Simulation von Flüssigmetallbatterien vor.

Fine gas dispersion into a liquid is requested in a number of industrial applications. One way to achieve finer gas dispersion is to downsize the openings at which the gas bubbles are generated. Accordingly, we have investigated the dynamics of bubble formation from submerged orifices ranging from 0.04 to 0.8 mm at a comprehensive range of gas flow rates for a system of air and deionized water. In this range of orifice size, we observe a different mechanism of bubble formation compared with millimeter-range orifices. We discuss the observations on the basis of temporal change of the bubble shape, bubble base expansion, and detachment criteria. At submillimeter orifices, the mechanism of bubble formation is highly influenced by the capillary pressure and the gas kinetic energy. The latter results in congregation of small bubbles in the vicinity of the orifice, even at very small gas flow rates. Moreover, we studied the evolution of individual forces applied to the surface of bubbles during their formation. We found that the formation of bubbles at submillimeter orifices cannot be described with a quasi-static force balance. Finally, we present a bubbling regime map using proper dimensionless numbers.

Metals make modern societies function, and increasingly, various high purity precious and special metals endow sustainability-driving technologies with specific functionalities. These metals become heavily intertwined within products, complicating end-of-life treatment. To counteract the resulting downcycling and potential depletion of scarce resources, maximising both the quantities and qualities of materials recovered during primary extraction and recycling processes should be a priority in the pursuit of sustainable circular economy.
Adopting a process simulation approach, a digital twin for the life cycle of cadmium-telluride solar photovoltaic (CdTe PV) modules was created. The system comprises an integrated metallurgical production system that produces, among others, cadmium, tellurium, selenium, zinc, copper, and lead, all of which are required to manufacture PV modules. System-wide resource efficiency and environmental impacts are assessed using exergy analysis and life cycle assessment, respectively.
Simulation of this large and complex product life cycle at a high level of detail allows for the evaluation of potential system-wide effects of various production, recycling and residue exchange scenarios aimed at maximising the sustainability of the entire system. It diminishes the need to make arbitrary choices about allocation methods for the distribution of environmental impacts in multiple-output production systems. Furthermore, it demonstrates the key importance of metallurgy in achieving Circular Economy.

Combined field structural analysis with in situ EPMA (electron probe microanalysis) Th-U-Pb monazite dating, petrologic and microstructural data provide a reconstruction of the pressure-temperature-deformation-time (P-T-D-t) path of the Gondwanide basement of the North Patagonian Cordillera. For samples from the Challhuaco hill, the timing of development of the metamorphic S2 foliation and associated L2 lineation and tight to isoclinal F2 folds is constrained by monazite ages of 299 ± 8 and 302 ± 16 Ma during peak metamorphic conditions of ca. 650 °C and 11 kbar, achieved during prograde metamorphism and progressive deformation. Metamorphism and deformation of metamorphic complexes of the North Patagonian Andes seem to record Late Paleozoic crustal thickening and are coeval with metamorphism of accretionary complexes exposed further west in Chile, suggesting a coupled Late Devonian-Carboniferous evolution. Instead of the result of continental collision, the Gondwanide orogeny might thus be essentially linked to transpression due to advancing subduction along the proto-Pacific margin of Gondwana. On the other hand, a second generation of monazite ages of 171 ± 9 and 170 ± 7 Ma constrain the timing of low-grade metamorphism related to kink band and F3 open fold development during Jurassic transtension and emplacement of granitoids. Finally, a Cretaceous overprint, likely resulting from hydrothermal processes, is recorded by monazite ages of 110 ± 10 and 80 ± 20 Ma, which might be coeval with deformation along low-grade shear zones during the onset of Andean transpression.

The polymetallic veins in the Freiberg district form one of the largest epithermal systems in Europe. It produced over 5600 t of Ag during active mining between 1168 and 1969. Historically, exploration focused on the centre of the district, with peripheral sub-districts exploited only to shallow depth. Recent exploration activity focuses on these peripheral regions, yet only a limited amount of modern geochemical data is available and the underlying ore-forming processes are insufficiently understood. Here, we present preliminary geochemical, fluid inclusion, and petrographic data for 55 samples from the historical mine camps of Reinsberg and Kleinvoigtsberg (northern peripheral sub-district). Samples were selected from the scientific collections of the TU Bergakademie Freiberg and collected from outcrops in the field. They include vertical profiles of two major veins extending from 18 to 532 meters below ground level. The data is combined with previous literature descriptions to develop a genetic model for the northern sector of the Freiberg district. Mineralisation in the Reinsberg and Kleinvoigtsberg mine camps is hosted by polystadial Ag-(Au)-Zn-Pb veins. The paragenetically oldest mineralisation, Stage I, is dominated by base metal sulphides and quartz; it has been encountered most prominently in the deepest levels of the historic mines. The occurrence of carbonates and the introduction of Ag-Sb sulphides and sulfosalts mark the transition to Stage IIa. At shallower mining levels, carbonate recedes and quartz returns as the major gangue mineral, indicating the transition to Stage IIb. Stage IIb vein infill is often breccia-textured and carry the highest silver grades. At the present day surface, veins consist of quartz and host rock fragments, forming a cockade breccia texture (stage III). Although no visible sulphides are present, such quartz breccias contain up to 2.5 g/t Au. Recent studies show that the main ore-forming process in the northern district seems to be cooling - causing distinct district and vein-scale zoning. Effervescence of CO2 is most likely the underlying process behind the transition from quartz to carbonate gangue. An understanding of mineral zonation and its underlying ore-forming processes can be translated into mappable exploration criteria. In this case, the highest ore grades (Ag and Au) are associated with Stage IIb (Ag-Sb-sulfosalts-quartz assemblage). This assemblage occurs always wedged between the carbonate-rich assemblage of Stage IIa (below) and the sulphide-poor quartz Stage III (above). This systematic relation may well constitute an important exploration vector for the Freiberg district.

The Freiberg epithermal system comprises numerous hydrothermal veins with rich Ag-(Au)-Pb-Zn-Cu mineralisation. Even after more than 800 years of extensive mining, substantial resources remain in the northern sub-districts. This area is subject to recent exploration activity. Preliminary petrographic data of two vertical profiles from the northern part of the district are presented and a new model for the district-scale zoning is proposed. The highest Ag grades occur in Ag-Sb-S-quartz veins and seem to systematically occur above an Ag-Sb-S-Carbonate stage and below Sb-S-quartz mineralisation. This high-grade Ag mineralisation is relatively distal, shallow, and abundant in the northwest sector of the Freiberg district. This, and similar insights may be used to develop new exploration vectors for the Freiberg district.

Metal zonation is an important feature of low-temperature carbonate-hosted Zn-Pb deposits. Its origin, however, remains poorly understood. In this article, we use the Lisheen deposit in Ireland as a case study to show how thermodynamic modelling can explain these zonation patterns. Based on input data derived from fluid inclusion studies, bulk ore geochemistry and accepted models of ore formation in the Irish Orefield we construct a reaction path model that successfully accounts for the major features of the mineralisation, most importantly the presence of Cu-Ni-As-rich core zones around hydrothermal feeder structures, surrounded by more distal Fe-Zn-Pb-rich mineralisation. The outcomes of this study strongly support current metallogenetic models for Irish-type deposits and have implications for near-deposit exploration.

A-type granites record ancient rifting events and host deposits of high-tech metals, such as the rare earth elements (REE). We have studied the geology, geochemistry, geochronology and Sm-Nd isotope compositions of a globally uncommon suite of ca. 2.04–2.06 Ga ferroan A1-type igneous rocks in central Finland, Fennoscandian Shield[1]. The suite consists of gneissic peralkaline to peraluminous granites and related syenite, monzonite and monzodiorite[1].
The Otanmäki A-type rocks have εNd(2050 Ma) values ranging from +2.5 to -3.4 and trace element characteristics similar to ocean island basalts (OIB), suggesting their derivation from mafic mantle-derived parental magmas similarly as has been proposed for many other A1-type suites globally[1]. However, the peraluminous granites exceptionally show Nb/U, Nb/Yb and Th/Yb ratios more similar to those of Archean granitoids than OIBs, indicating role of crustal contamination in their genesis[1].
The Otanmäki suite A-type rocks host two Nb-Zr- REE deposits: Kontioaho, consisting of an up to 50-m-thick tabular granitic body, and Katajakangas, comprising several closely-spaced 0.1- to 1.4-m-thick quartz-rich veins. A peraluminous monzogranite forms the wall rock for both deposits, but the mineralized rocks have a geochemical signature similar that of peralkaline-metaluminous alkali feldspar granite adjacent to the monzogranite. The main ore minerals are allanite, zircon and titanite with minor Nb-REETh-U oxides. Geochemical and geochronological data and Nd isotope compositions of the mineralized rocks indicate that they formed from highly fractionated, volatile-bearing (e.g., F, CO2) late-stage residual melts of the A-type magmatism.

[1] Kärenlampi, K., Kontinen, A., Huhma H. & Hanski, E. Geology, geochemistry and geochronology of the 2.05 Ga gneissic A1-type granites and related intermediate rocks in central Finland: implication for the tectonic evolution of the Karelia craton margin. Bulletin of the Geological Society of Finland (2019) (in press)

The determination of long-lived radionuclides by means of accelerator mass spectrometry (AMS) is usually outstandingly successful when an interdisciplinary team comes together. The “heart” of AMS research is of course an accelerator equipped with sophisticated ion sources, analytical tools and detectors run by experienced and ambitious physicists. Setting-up and further developing AMS systems is one of the most interesting and challenging topics.
Another essential part in AMS research is the radiochemical sample preparation preceding the measurement where the goals are: 1.) Enrichment of nuclides of interest by reduction of the matrix. 2.) Depletion of isobars. 3.) Production of a thermally stable chemical compound such as AgCl, AgI, Al₂O₃, BeO, CaF₂, Fe₂O₃, MnO₂ etc. of relatively high purity.
One of the most interesting applications of AMS is the analysis of extraterrestrial material such as meteorites. While being at the surface of their so-called parent body (asteroids, Moon, Mars,…) and again while travelling through space as a so-called meteoroid, these unique pieces are bombarded by high-energy particles from the cosmic radiation. Long-lived radionuclides are produced in the material by nuclear reactions in both stages potentially until saturation. However, they start decaying in a third stage, when meteorites have landed on Earth because the cosmic radiation is shielded by the Earth’s atmosphere and magnetic field. Hence, the concentrations of radionuclides are records of all three stages allowing the reconstruction of the exposure history (duration, shielding, size,…) of the individual meteorite and the cosmic radiation itself.
Meteorite projects and projects with artificially-irradiated targets are also well-suited to develop measurements of “new” AMS radionuclides as the isotopic ratios are at much higher levels (up to 10^-10 radioactive/stable) than e.g. in terrestrial natural samples (10^-14-10^-16). The AMS community is very open to any input and questions from “outside”. The DREsden AMS (DREAMS) and other European AMS facilities offer researchers from academia free measurements via a Trans-National-Access proposal program (www.ionbeamcenters.eu) and also national access (www.dresden-ams.de; DREAMS only).

Based on a combination of bulk-ore geochemistry and mineralogical and microanalytical data, this study is the first to develop a quantitative model of indium deportment in massive sulfide ores, demonstrating how regularities in indium partitioning between different minerals can be used to predict its mineralogical deportment in individual drill-core samples. Bulk-ore assays of As, Cu, Fe, Pb, S, Sb, Sn, Zn, and In are found to be sufficient for reasonably accurate predictions. The movement of indium through the ore processing plants is fully explained by its mineralogical deportment, allowing for specific mine and process planning. The novel methodologies implemented in this contribution for (1) the assessment of analytical uncertainties, (2) the prediction of complex mineralogical deportments from bulk geochemical data, and (3) the modeling of byproduct recoveries from individual mining blocks, are of general applicability to the geometallurgical assessment of many other byproduct metals in polymetallic sulfide ores, including Ga, Ge, Mo, Re, Se, Te, as well as the noble metals.

The Kalgoorlie district in the Archean Yilgarn Craton of Western Australia containstwoworld-classgolddeposits:thegiant Golden Mile shear-zone system and the Mt Charlotte quartz-vein stockworks. Mineralization occurs in three styles:(a) Fimiston style is characterized by ankerite-pyrite ± hematite-magnetite-gold replacement, (b) Oroya style overprintsFimiston ore in the shear zones and is characterized by silica-ankerite-V-muscovite-pyrite ± pyrrhotite-gold-telluridereplacement and (c) Mt. Charlotte style is characterized by veins with ankerite-sericite ± albite-pyrite-pyrrhotite-goldselvages. Hydrothermal pyrite is ubiquitous in all styles and occurs in several stages. Laser ablation inductively coupledplasma mass spectrometry (LA-ICP-MS) spot analyses (n= 652) were collected on 54 representative samples of pyritefrom three deposits. Smooth sections in the ablation spectra were selected for quantitative analysis excluding peakscaused by micron-sized inclusions. Linear mixed effects (LME) modeling of the analytical results indicates no system-atic differences between the Fimiston, Oroya and Mt Charlotte styles. The variance introduced to the dataset bygeological variability reflected in random differences between samples and deposits is large. This may be a major reasonfor difficulties in distinguishing the differences due to mineralization style. However, there are clear differences betweenpyrites co-existing with different mineral assemblages. These indicate a strong control on pyrite chemistry by thecomposition of the hydrothermal fluids. Finally, Au-Te-As systematics show that a substantial proportion of the analyzedpyrites in all deposits fall into the field of gold saturation consistent with the known metallurgical character of the ores.Mineralogical studies, ultra-fine grinding and recovery by cyanide leach show that > 82% of all gold is present in nativegrains or in Au-Ag-tellurides. The refractory nature of theFimiston pyrite concentrates is due to clusters of micron- tonano-sized inclusions rather thandue to abundant lattice-bound gold.

The Felbertal tungsten deposit is situated in the Hohe Tauern range, near Mittersill, Austria. The ore is hosted in the volcano-sedimentary, polymetamorphic units of the Pre-Permian Habach Complex as disseminated and stockwork mineralization, mostly associated to quarz. An Eastern and a Western ore zone (EOZ and WOZ), which are spacially devided by the NS oriented valley, have been distinguished. The genetical relation of different postulated mineralization events of scheelite in the EOZ and WOZ has not yet been fully resolved. Previous studies reported four different generations, characterized mainly by different fluorescence colour and molybdenum (Mo) content. The first and second generation are characterised by yellow fluorecence and relatively high Mo contents, whereas the later third and fourth generation where observed to have whitish to blue fluorescence colour with low Mo concentration. Processes of remobilisation and recrystallization have been accepted to be responsible for different generations.(Höll, R., & Eichhorn, R., 2000)

Formly less well explored ore bodies have been targeted in the WOZ in the last years. Scheelite in this study was collected in recently worked districts of the mine, namely K8 ore body, K2 Brekzie and scheelite-dotted (SD)-gneiss. Associated scheelites display complex and diverse zonation under UV light.

To target this, new quantitative and qualitative analysis of scheelites have been made using electron probe micro analysis (EPMA). Qualitative molybdenum distribution maps, quantitative element profiles and cathodoluminescence (CL) images have been combined with microtextural analysis to reveal a new view into the mineralisation history.
Molybdenum distribution maps of scheelite grains between 0,5 and 300 mm are of multiphase character with often sharp, irregular edges between plateaus of even concentration, fractures and peripheral areas contain microscale Mo-sulfides. Profiles show a mostly fluctuating pattern between concentrations of 0,00 to 4,14 wt% ox. Mo. The element maps reveal a more complex microscale distribution of Mo, than can be visualized by UV-light.
Under the microscope scheelite shows ondulating extinction, complex fracturing and occasional recrystallization.

The formation of the scheelite apparently involved multiple dissolution and reprecipitation during a fluid-mineral interaction where relatively Mo-poor scheelite replaced Mo-rich scheelite. This was followed by predominantly brittle deformation but with occasional dynamic recrystallization of scheelite. These new observations will ultimately influence the genetical interpretation of the Felbertal tungsten deposit.

References:

Höll, R., & Eichhorn, R. (2000). Tungsten mineralization and metamorphic remobilization in the Felbertal scheelite deposit, Central Alps, Austria. Chapter, 11, 233-264.

The halogens Cl and Br are sensitive indicators for the origin of ore-forming fluids. Here, we use a combination of microchemical and microscopic methods to show that measurable concentrations of these elements commonly occur as atomic-scale substitutions within hydrothermal sphalerite. Furthermore, the Cl/Br ratios of the halogen-rich sphalerites investigated in this study are indistinguishable from those of the corresponding ore fluids. Thus, they record fluid compositions, which are in turn closely related to fluid origin. Given the abundance of sphalerite in hydrothermal base-metal deposits, as well as the relative ease of conducting in-situ microchemical analyses, the halogen signature of sphalerite has the potential to become a sensitive proxy to distinguish between different ore-forming environments.

The Gorevskoe Pb-Zn-Ag Mine is currently the largest producer of Pb and Zn in Russia, exploiting one of the largest sediment-hosted Pb-Zn deposits worldwide. Despite its size and economic importance, the Gorevskoe deposit remains poorly understood. It is located on the western margin of the Siberian Craton within the Yenisei Ridge, a Neoproterozoic orogenic belt. Mineralization consists of three tabular orebodies that are in turn composed of multiple stacked stratiform to stratabound lenses of galena-pyrrhotite-sphalerite-rich massive sulfide ores, hosted in organic-rich marine metalimestones and calcareous slates of Stenian to Tonian age (1,020 ± 70 Ma). Extensive Fe-Mg-Mn-carbonate alteration haloes surround the ore lenses in the hanging wall and the footwall. The Pb isotope signature of the deposit is consistent with derivation of the Pb, and probably all associated metals, from an evolved crustal source at the time of formation of the host rocks. The sulfur-isotopic composition of pyrrhotite, along with sphalerite, galena, arsenopyrite and pyrite (δ34S = 16.0 – 20.4 ‰) is within the range reported for contemporaneous seawater, indicating complete reduction of marine sulfate as the main source of sulfide.
The available geological and geochemical data indicate that the Gorevskoe deposit belongs to the sediment-hosted massive sulfide class of Zn-Pb deposits, with an affinity to Selwyn-type deposits. Hydrothermal mineralization appears to be related to rifting and distal mafic volcanism in a passive margin setting. Geological relationships suggest that sulfide orebodies formed in a diagenetic environment. Furthermore, the predominance of primary pyrrhotite over pyrite as the major iron sulfide, the presence of abundant siderite, and the virtual absence of barite from the deposit, all indicate highly reducing conditions during ore-formation. They also constrain the character of the metal-bearing fluid to be similarly reducing, and of moderate temperature (200 – 300°C). Gorevskoe may thus be regarded as one of the world’s largest Selwyn-type SHMS deposits.

The Saxothuringian Zone of the Variscan orogen is composed of autochthonous and allochthonous domains. Dating of metamorphic events in the domains of the Saxonian Granulite Massiv, and the Münchberg, Frankenberg, and Erzgebirge nappe units is critical for resolving the complex geodynamic evolution during the Variscan orogeny. The in-situ chemical Th-U-Pb monazite (Th, U, Si, LREE, Y, Ca)PO4 dating by electron probe microanalysis (EPMA) has demonstrated its high potential to resolve polyphase metamorphism. The method is based on the premise that monazite inherits negligible amounts of common Pb and that the radiogenic Pb is retained due to very low diffusion rates even at high T [1]. A monazite dating routine, enclosing the analysis of HREE, was performed with a JEOL-8530F, producing 100 - 200 single analyses per sample. Also, energy dispersive x-ray mapping (GXMAP) by automated SEM was used for semiquantitative identification of garnet zonation pattern. Quantitative chemical compositions of garnet and related plagioclase, biotite and muscovite were then measured by EPMA for geothermobarometric estimates by cation exchange and net transfer reactions. Monazite is abundant in lenses of granulitic garnet gneisses ("saidenbachites") in the central Erzgebirge UHP unit. The monazite ThO2*-PbO data straightly define isochrons at around 335±3 Ma. High pyrope (27 mol%) garnet crystallised at 830 °C/19 kbar [2]. Despite such high T, the monazite Y contents are low. In the intercalated MP micaschists, the monazite ThO2*-PbO isochrones appear more diverse, between 334±4 and 344±5 Ma. Furthermore, monazite has been studied in the micaschists and related phyllites of the western Erzgebirge. The monazite ThO2*-PbO data define isochrones between 323±10 and 360±10 Ma, with most samples around 340 Ma, interpreted as the ages of Variscan regional metamorphism. Several samples bear an older minor monazite population at ages between 415 to 432 Ma. Special regard has been dedicated to metapelites within the Pöhla mineralisation. The Eibenstock granite Th-U-Pb monazite isochrone is at 321±2 Ma. In non-mineralised micaschists older monazites (329±8 Ma), and in mineralised parts younger (309±6 Ma) and hydrothermal low-Th monazites are observed.

[1] Montel, J.-M., Foret, S., Veschambre, M., Nicollet, C., Provost, A. (1996): Electron microprobe dating of monazite. - Chem. Geol., 131: 37-51.
[2] Tichomirowa, M., Whitehouse, M., Gerdes A., Schulz, B. (2018): Zircon (Hf, O isotopes) as melt indicator: Melt infiltration and abundant new zircon growth within melt rich layers of granulite-facies lenses versus solid-state recrystallization in hosting amphibolite-facies gneisses (central Erzgebirge, Bohemian Massif). - Lithos 302–303.

Indium-bearing sphalerites from the Hämmerlein skarn deposit, located in the western Erzgebirge (Germany), show complex distribution patterns of major and minor elements on a micrometer to sub-micrometer scale. However, with the spatial resolution of traditional analytical methods, such as SEM-based image analysis and field emission electron probe microanalysis (FE-EPMA), many features in these samples cannot be resolved. It remains unclear whether Cu, In and Fe are in solid solution in the sphalerite or form discrete phases.
Atom probe tomography combined with transmission kikuchi diffraction has been used to resolve the compositional heterogeneity and the nanostructure of these complex In-Cu-Fe-sphalerites. The obtained data indicate a complex structure with micro- to nanometer sized, plate-shaped inclusions of chalcopyrite in the sphalerite. In addition, a nanometer scale In-Cu-sulfide phase forms plate-like segregations in the sphalerite. All types of segregations have similar crystal structure and record the same crystal orientation indicating that they likely formed by exsolution.
The results indicate that complex sulfides containing cations of more than one element as minor or major constituents may represent discrete, exsolved phases, rather than solid solutions. This heterogeneous nature will affect the nanoscale properties of the sphalerite, which may have implications for the economic extraction of precious elements such as In. Furthermore these nanoscale properties will open up new perspectives on formation processes of In-Cu-Fe-sphalerites, which might be relevant for other chemically complex minerals as well.

Indium-bearing sphalerites from the Hämmerlein skarn deposit, located in the western Erzgebirge (Germany), show complex distribution patterns of major and minor elements on a micrometer to sub-micrometer scale. However, with the spatial resolution of traditional analytical methods, such as SEM-based image analysis and field emission electron probe microanalysis (FE-EPMA), many features in these samples cannot be resolved. It remains unclear whether Cu, In and Fe are in solid solution in the sphalerite or form discrete phases.
Atom probe tomography combined with transmission Kikuchi diffraction has been used to resolve the compositional heterogeneity and the nanostructure of these complex In-Cu-Fe-sphalerites. The obtained data indicate a complex structure with micro- to nanometer sized, plate-shaped inclusions of chalcopyrite in the sphalerite. In addition, a nanometer scale In-Cu-sulfide phase forms plate-like segregations in the sphalerite. All types of segregations have similar crystal structure and record the same crystal orientation indicating that they likely formed by exsolution.
The results indicate that complex sulfides containing cations of more than one element as minor or major constituents may represent discrete, exsolved phases, rather than solid solutions. This heterogeneous nature will affect the nanoscale properties of the sphalerite, which may have implications for the economic extraction of precious elements such as In. Furthermore these nanoscale properties will open up new perspectives on formation processes of In-Cu-Fe-sphalerites, which might be relevant for other chemically complex minerals as well.

The Schwarzenberg district (SD) in the western Erzgebirge comprises a series of polymetallic skarn bodies with significant resource potential for Sn, W, Zn, and In. Skarn mineralisation in the SD is hosted by low- to medium-grade metasedimentary units forming the so-called Schwarzenberg Gneiss Dome (SGD). Recent exploration, mainly for Sn, W, and In, targeted the large Globenstein, Hämmerlein and Tellerhäuser skarn bodies (several km strike length). Fertile skarn mineralisation in these skarns is related to the late- to post-collisional phase of the Variscan Orogeny (325-295 Ma). Economically important large skarn bodies as well as smaller satellites of the SGD have thus far only been investigated individually, rather than being considered part of a potentially district-wide mineralizing system (~ 12 x 15 km). The Waschleithe skarn in the far north of the SGD is a typical example for a smaller skarn body. Considering its distal position within the SGD it provides valuable insight into district-scale mineral zoning. Mineralisation occurs within two skarn horizons hosted by marble interlayered with mica schists. The sharp contact between skarn and marble is well exposed in historical mine workings. Coarse-grained pyroxene (hedenbergite-diopside), finer-grained subordinate yellowish-green andraditic garnet and Mn-rich pyroxenoids are the dominant constituents of the prograde skarn mineral assemblage. All of them overprint the metamorphic microfabric of the marble. A retrograde skarn assemblage is only weakly developed and consists mainly of ilvaite, epidote, vesuvianite, amphibole, chlorite, quartz, fluorite and hydrothermal calcite. Ore minerals associated with the retrograde mineral assemblage may be grouped into three different assemblages: 1) magnetite, 2) sphalerite, galena, pyrite, and chalcopyrite and 3) scheelite. The retrograde ore mineral assemblages show no association with paragenetically late chlorite, indicating that they formed relatively early during retrograde skarn formation. The marble front, dark pyroxenes, relatively low garnet/pyroxene ratios and the presence of Mn-bearing pyroxenoids indicate that the Waschleithe skarn formed distal to its fluid source relative to skarns with a more proximal mineralogy, such as Hämmerlein. Thus, Waschleithe represents a distal equivalent to the larger skarns of the SGD situated farther to the south. A genetic link between the skarns of the SGD requires a substantial re-evaluation of the size and exploration potential of this mineral system. To test this hypothesis a comprehensive set of mineralogical, geochemical and geochronological data from several skarn bodies of the SGD is currently being acquired.

The Waschleithe skarn located near Schwarzenberg in eastern Germany hosts sub-economic polymetallic W-Zn-Pb-Cu-Fe mineralisation. Its mineralogy is dominated by prograde clinopyroxene and subordinate garnet. The garnet and pyroxene colours of this skarn as well as low garnet/pyroxene ratios are typical for distal skarn settings. Ore minerals (magnetite, sphalerite, galena, chalcopyrite, pyrite, scheelite) in the prograde skarn do not show a clear association with the weakly developed retrograde overprint consisting mainly of late chlorite and calcite.

Recently, considerable concerns have been raised about the supply security of certain high-tech elements produced as by-products. To determine in how far these concerns are justified by the actual availability of these elements, a new method was developed to estimate supply potentials, including statistical uncertainties. This was applied to three relevant examples – Ga, Ge and In – to compare their global availability to current and historic production volumes. The assessment is based on detailed estimates of the amounts extractable from various raw material streams given contemporary market prices and technologies. The results show that the supply potentials of all three elements significantly exceed current primary production. However, the degree to which this is the case varies from element to element. Differences also exist in historic growth trends, with indium showing the fastest growth rate of production relative to supply potential at the time of analysis.

Ion beam induced amorphization of semiconductor nanostructures limits the applicability of ion beam processing to semiconductor nanostructures. Here, we present an approach that not only avoids this amorphization but in addition allows to tailor the lateral device dimensions of pillars and fins used in modern GAA and Fin-FET designs. Si nanopillars (diameter: 25–50 nm) have been irradiated by either 50 keV broad beam Si + or 25 keV focused Ne + beam from a helium ion microscope (HIM) at various temperatures using fluences of 2×10 16 cm −2 and higher. While at room temperature strong deformation of the nanopillars has been observed, the pillar shape is preserved above 325 ∘ C. This is attributed to ion beam induced amorphization of Si at low temperatures allowing plastic flow due to the ion hammering effect and surface capillary forces. Plastic deformation is suppressed for irradiation at elevated temperatures. Above 325 ∘ C, as confirmed by diffraction contrast in BF-TEM, the nanopillars remain crystalline, and are continuously thinned radially with increasing fluence down to 10 nm. This is due enhanced forward sputtering through the sidewalls of the pillar, and agrees well with 3D ballistic computer simulations.
Supported by the H-2020 under Grant Agreement No. 688072.

On the effect of liquid viscosity, density and surface tension on the hydrodynamics of TSL injection systems,
Main features
Top-submerged gas injection
Submerged combustion
Smelting of non-ferrous metals
Example: copper from chalcopyrite (CuFeS2 )
Importance of hydrodynamics:
gas-liquid interface
intensity of mixing
splashing
lance cooling/coating

CFD modelling of combustion and heat transfer in the TSL smelter.
The importance of viscous and interfacial forces on the hydrodynamics of the TSL furnace
An experimental and numerical investigation of TSL gas injection in liquid metal

The main goal of this work is to prove the reliability of the Volume of Fluid (VOF) model for a top-submerged-lance (TSL) gas injection in a liquid metal bath, therefore trying to close the gap between the modelling of common air/water lab setups and real TSL slag-bath furnaces. Suitable validation data were provided by HZDR, where X-ray imaging was applied to picture the multiphase flow in an Argon - Ga77.2In14.4Sn8.4 system [1].

The title of a paper we wrote for this journal in 2014 "Copper: A Key Enabler of Resource Efficiency", or to rephrase it in light of the present Circular Economy (CE) paradigm "Copper: A Key Enabler of the Circular Economy", rings as true as ever.

Polystyrene-Gold (PS-Au) Janus and Polystyrene-Silver/Silver Chloride (PS-Ag/AgCl) nanomotors (Fig.1) with aspect ratios (length divided by width) ranging from 10 to 15 have been prepared by template based synthesis using anodic aluminium oxide (AAO) followed by replication methods presented in this work. The wettability transition from wetting to nonwetting of PS inside the cylindrical pores of AAO template in nonsolvent polyethylene glycol was used to manipulate the morphology of PS nanorods. To generate anisotropy in surface chemistry of nanorods, we deposited 15 nm Au or 30 nm Ag layers running along the minor axis. The trajectories of the Janus nanorods were captured by mean of video microscopy and analyzed in term of the MSD and MSAD. The fabricated PS-Au Janus nanoparticles showed the efficient decomposition of hydrogen peroxide even at very low concentrations ranging from 0.1% to 0.4%. For the PS-Ag/AgCl Janus nanorods exposed to blue light, the generation of the local chemical gradient led to changes in rotational behavior of single nanorods.

In this work, the integration of an atomic force microscope (AFM) into a helium ion microscope (HIM) is reported for the first time. The helium ion microscope is a powerful instrument, capable of sub-nanometer resolution imaging and machining nanoscale structures, while the AFM is a well-established versatile tool for multiparametric nanoscale metrology. Combining the two techniques opens the way for unprecedented, in-situ, correlative analysis at the nanoscale. Nanomachining and analysis can be performed without contamination of the sample as well as avoiding environmental changes between processing steps. The practicality of the resulting tool lies in the complementarity of the two techniques as the AFM offers not only true 3D topography maps---something the HIM can only provide in an indirect way---but also allows for nanomechanical property mapping, as well as electrical and magnetic characterisation of the sample after focused ion beam materials modification with the HIM. The experimental setup is described and evaluated through a series of correlative experiments, demonstrating the feasibility of the integration.

Diamond drilling is used in the mining industry to extract drill-cores for characterising mineral deposits. Traditionally, drill-cores are visually analysed by an on-site geologist, subjected to geochemical analyses, and then, few representative samples subjected to additional high-resolution mineralogical studies. However, the choice in samples is frequently subjective and the mineralogical analyses are highly time-consuming. In order to optimize the choice of samples and accelerate the analyses, drill-cores can be partitioned into domains, and then, laboratory analyses can be carried out on selected domains. Nevertheless, in the mining industry, automatic drill-core domaining still remains a challenge. Recently, hyperspectral imaging has become an important technique for the analysis of drill-cores in a non-invasive and non-destructive manner. Several clustering algorithms of hyper-spectral data are proposed for automatic drill-core domaining. In this paper, we suggest using advanced subspace clustering algorithms (i.e., sparse subspace clustering algorithm, spectral-spatial sparse subspace clustering algorithm). These algorithms work based on the self-representation property of the hyperspectral data. The clustering methods are tested on two drill-core samples which present different mineralogical and structural features. The subspace clustering algorithms are compared with the result of the K-means clustering algorithm. Our experimental results show that subspace clustering algorithms provide accurate drill-core domains and it is shown that including spatial information significantly improves the clustering results.

While there is a constantly increasing interest in HIGEE technology and rotating packed beds in particular for the intensification of gas-liquid and vapor-liquid mass transfer, especially in reactive systems, there is still a need for detailed investigations of the mass transfer and hydrodynamic performance. Classical isotropic single block packings, constructed from wired and knit mesh or foams constitute the most applied and investigated packings for absorption and stripping processes. Yet, the large geometric surface area which is offered by these packings can hardly be exploited to the full extend due to the constant change in gas and liquid loads along the radius of the torus-shaped packings. In order to overcome these limitations and extend the operating range and mass transfer performance of foam packings, the current study presents a detailed comparison of isotropic and anisotropic packings. The conducted pressure drop and mass transfer experiments, based on chemical absorption of CO2 with aqueous sodium hydroxide, illustrate the improved performance that can be expected from anisotropic packings, while dedicated gamma-ray computed tomography provides further insight into the improved liquid distribution for these kind of packings.

Determination of the mineral compositions of an ore deposit is a vital task in exploration campaigns. HyperSpectral (HS) imaging is an emerging technology that is becoming popular in the mining industry. Specially, analyzing drill core HS data enables geologists to map minerals in mining projects in a fast and non-destructive manner. There are several methods to analyze the acquired drill cores. While traditional approaches such as X-Ray diffraction (XRD) can be subjective and are time consuming, the new machine learning based techniques applied on drill core HS scans have shown promising results. By using machine learning techniques, geologists are able to identify representative areas of drill core samples to apply traditional laboratory analysis.In recent studies, advanced unsupervised learning techniques to cluster HS data have shown great performance. Specially subspace clustering methods (i.e., sparse subspace clustering, low rank representation clustering) obtained more accurate results than the traditional clustering methods (e.g. K-means) for the analysis of this data. This is mainly because of the fact that each pixel may contain several minerals rather than a single phase. Therefore, the drill core HS data can be better represented as a union of low dimensional subspaces.In this work, we propose a new subspace-based method to cluster drill core HS data. It has been shown in the literature that incorporating spatial information will improve the classification results of HS data. Thus, in this work, we suggest including spatial information in the sparse subspace clustering method. In the classical sparse clustering method, only spectral information being used to cluster HS data. While, by adding information from the surrounding of each pixel in the classical sparse formula, the performance of the subspace clustering method will be improved. The method was applied to VNIR-SWIR hyperspectral data. Qualitative validation was provided by scanning electron microscopy based Mineral Liberation Analysis (SEM-MLA) on some areas of interest. Results indicate that the proposed method is promising, compared to existing clustering methods

Silicon carbide is a very promising platform for quantum applications because of the extraordinary spin and optical properties of point defects in this technologically friendly material. These properties are strongly influenced by crystal vibrations, but the exact relationship between them and the behavior of spin qubits is not fully investigated. We uncover the local vibrational modes of the Si vacancy spin qubits in as-grown 4H-SiC. We apply microwave-assisted spectroscopy to isolate the contribution from one particular type of defects, the so-called V2 center, and observe the zero-phonon line together with seven equally separated phonon replicas. Furthermore, we present first-principles calculations of the photoluminescence line shape, which are in excellent agreement with our experimental data. To boost up the calculation accuracy and decrease the computation time, we extract the force constants using machine-learning algorithms. This allows us to identify the dominant modes in the lattice vibrations coupled to an excited electron during optical emission in the Si vacancy. A resonance phonon energy of 36 meV and a Debye-Waller factor of about 6% are obtained. We establish experimentally that the activation energy of the optically induced spin polarization is given by the local vibrational energy. Our findings give insight into the coupling of electronic states to vibrational modes in SiC spin qubits, which is essential to predict their spin, optical, mechanical, and thermal properties. The approach described can be applied to a large variety of spin defects with spectrally overlapped contributions in SiC as well as in other threeand two-dimensional materials.

Geophysical methods for mineral exploration require cost- and time-effective ways to acquire high resolution data to supplement field mapping. During the last few years, lightweight magnetometers and hyperspectral imaging (HSI) sensors have been increasingly and independently developed for their use on unmanned aerial systems (UAS). We propose that the combination of hyperspectral images and UAS aeromagnetic surveys can provide a rapid and cost-effective technology to improve the detection of shallow targets and to delineate mineral structures in potentially hazardous terrains where traditional techniques cannot be operated safely. With low altitude flights and tight flight lines, UAS aeromagnetic surveys can help overcome the scale gap between ground and air-borne magnetics and deliver high resolution maps. However, data corrections are required for UAS aeromagnetic data to achieve valid observations and reliable maps. For this study the main magnetic compensations applied to the magnetics were meant to attenuate temporal variations, headings and maneuvering errors. The interpretation of accurate total field maps can be improved with the aid of hyperspectral images. HSI are widely used in geological mapping and mineral exploration (e.g., van der Meer et al., 2012, Jakob et al., 2016). A comprehensive data set including hyperspectral images and handheld spectral measurements of the study area in Siilinjärvi, Finland, was acquired before the UAS aeromagnetic survey was performed. The UAS magnetics was acquired at 40 m height, with a line spacing of 20 m, covering an area of 3.894 ha.
Data processing of the UAS aeromagnetic data revealed the importance of making appropriate corrections for the reliability of the total magnetic intensity (TMI) and derived maps. Results suggest that UAS aeromagnetic data captured the main geological trends of the area by applying pertinent corrections. Aided by the HSI information, the sources of the magnetic anomalies were identified. A high magnetic contrast created by a syenite intrusion located in a glimmeritic carbonatite complex is consistently delineated by the UAS aeromagnetic data. Outcropping areas of the syenite intrusion can also be identified in the available hyperspectral image of Siilinjärvi.

Janus particles are artificial microswimmers with potential applications, including photonics, catalysis, and drug delivery. It has different shapes and responsive materials and could be employed to investigate new physical effects. We demonstrate the swimming behavior of one-, two- and three-janus particles clusters with magnetic caps under the influence of hydrogen peroxide and magnetic field.

Due to the involvement of cyclooxygenase-2 (COX-2) in carcinogenesis, COX-2-selective inhibitors are increasingly studied for their potential cytotoxic properties. Moreover, the incorporation of carboranes in structures of established anti-inflammatory drugs can improve the potency and metabolic stability of the inhibitors. Herein, we report the synthesis of carborane-containing derivatives of rofecoxib that display remarkable cytostatic activity in the micromolar range with excellent selectivity for melanoma and colon cancer cell lines over normal cells. Furthermore, it was shown that the carborane-modified derivatives of rofecoxib displayed different modes of action that was dependent on the cell type.

Microswimmers are objects capable of converting applied energy into active motion, resulting in its propulsion in a medium. The shape and chemical compound of the microswimmer strongly influence its propulsion properties. Here we investigate a template-based approach for fabrication of particles with controlled composition, size, and shape, which can be used as fundamental units for the preparation of microswimmers. Polystyrene nanorods with different configurations of the tip shape were fabricated with an aspect ratio of 10:1. The ratio of length-to-width (i.e. aspect ratio) can be easily modified by controlling the surface properties of the template. The wettability transition of polystyrene was used to manipulate the morphology and entrapment of polymer nanostructures

Unmanned aerial systems (UASs) for aeromagnetic surveying are currently an advantageous and suitable alternative for a large variety of geophysical applications, such as mineral exploration. UASs equipped with lightweight fluxgate magnetometers can rapidly provide high resolution magnetic data under conditions where traditional surveys cannot operate safely. Furthermore, UAS-borne magnetic acquisition offer a new mapping scale to overcome the gap between terrestrial and manned airborne surveys in a cost-effective way. However, there are several sources of magnetic interferences that compromise the measurements of the Earth's magnetic field, affecting the validity of observations and causing the development of unreliable maps. We address magnetic interference at the initial stages of survey planning and later on during processing. Fluxgate triaxial magnetometers can simultaneously measure the three components of the geomagnetic field but the sensor must be oriented and the heading of the aircraft plays an important role. To characterize the heading error it was essential to perform a compensation test including the possible flight directions before or after survey acquisition. To best adjust to the specific conditions of this case study, a processing tool was designed and programmed to compute suitable corrections and attenuate magnetic interferences. The three main corrections applied to the data included the removal of temporal variations, maneuvering noise and heading errors.
To test the potential of UAS for mineral exploration we selected a former mine in Otanmäki, Finland, as study site. To explore the contribution of low altitude UAS flights to characterize and improve the detection of geological structures, the study area was surveyed at three different heights: 60 m, 40 m and 15 m. For validation purposes, previous aeromagnetic studies in the area were employed, among them a ground magnetic survey. With regards to the efficiency of the UASs for aeromagnetic surveying it is worth mentioning that none of the flights lasted more than 15 minutes. The validation revealed that the total magnetic field maps consistently delineate the iron-ilmenite-magnetite deposits that enclose the test area. As expected, the superior spatial resolution was reached by the 15 m flight survey. Corrections played an important role during data processing. Nevertheless magnetic interference by heading errors was crucial for the reliability of this study. Our results suggest that after applying the pertinent magnetic compensations, UAS aeromagnetic surveys constitute a robust tool for mineral exploration.

Direct interaction of the sigma-1 (σ1) receptor, an endoplasmic reticulum chaperone located in close vicinity to the mitochondrion, with a variety of proteins involved in essential processes regulating proliferation, survival, and death of cells, indicates a role of this protein in tumor biology. Since tumor therapies address precisely these processes to stop the growth of tumor cells, the σ1 receptor could be a suitable modulator of the effectiveness of selected therapies. Recent initial studies have shown not only antiproliferative effects of ligands targeting this protein, but also modulating effects in both chemotherapy and radiotherapy. However, in this regard the influence of functional expression of the σ1 receptor has not yet been fully clarified. The purpose of this pilot experiment was to investigate the role of σ1 receptor on cellular radiosensitivity in an in vitro model. Therefore, clonogenic assays were performed to assess the susceptibility of HEK293 cells, stably transfected with human σ1 receptor, towards irradiation (X-ray) in comparison to non-transfected cells. Moreover, irradiation combined with pharmacological treatment should prove whether agonistic and antagonistic ligand binding to σ1 receptor influences the effectiveness of radiation treatment. The data obtained are not fully conclusive by indicating, on the one hand, an involvement of σ1 receptor in radiation-induced effects along with pharmacological effects independent from the σ1 receptor level, on the other hand, suggesting limitations of the model used herein. Consequently, subsequent work will focus on the investigation of tumor cells with different receptor densities.

The growth outlook for the circular economy in the metallurgical industry has to be built on the deep knowledge of the secondary processes involved in the chain: metal recycling and waste recov-ery play a significant role to successfully close the loop in the metal cycle.
The top-submerged-lance (TSL) furnace technology, primarily designed for metal extraction, is gradually making headway on that perspective because of its technical and economical flexibility. To push the market in that direction, an intense research effort has to be put in the understanding of the fundamentals, from chemical-physical to the engineering aspects.
In the present work, the authors investigate the lance combustion and the heat transfer in a TSL fur-nace. The submerged combustion is a crucial aspect of this technology. The correct design and ap-plication of the lance and the appropriate gas flow conditions must ensure a well-defined value of the partial pressure of oxygen pO2, which drives the smelting reaction process of the mineral con-centrate in the liquid slag bath.
A CFD investigation of the lab-scale TSL furnace, located at TU Bergakademie Freiberg, is per-formed using ANSYS Fluent®: the furnace setup includes the submerged combustive injection into a Cu-slag bath, in absence of the concentrate stream. The analysis provides detailed insights of the fuel combustion and the interaction with the liquid slag. Besides that, the evaluation of the pO2 at the lance tip and the temperature distribution in the bath and in the lance wall represent an added value for the furnace controlling and optimization.

We develop an integrated sensor system to detect rare earth elements (REE) in natural minerals on-site. The system combines reflectance and photoluminescence (PL) spectroscopy in order to present a noninvasive alternative to conventional time-consuming and costly chemical analysis of drill cores in mineral exploration. The major benefit lies in the rapid gathering of continuous spatial information on the type and abundance of the REEs in drill cores. Additionally the sample material remains unharmed during the whole process. To maximise scan speed and sample throughput, our system operates in continuous line scan mode, with continuous sample flow beneath the detector.

A dynamic model was developed in SimuSageTM, of a Top Submerged Lance (TSL) furnace in a lead smelting application. The objectives of the model are to create a tool for process control and optimisation, and to describe the complex metallurgical process which results from increasingly complex feed materials (from primary and secondary sources). Thermodynamic equilibrium models, e.g. created from FactSage, can be used to estimate the distributions of elements between phases. Likewise, laboratory equilibrium measurements for many elements are available. However, a dynamic model is required to address the fact that mass transfer processes are probably controlling smelting processes, especially in the TSL where evaporation of volatile elements should be taken into account. SimuSageTM is a flowsheet software package dedicated to modelling metallurgical processes by the Connected Local Equilibria method. Equilibrium compositions in process nodes are calculated by means of a Gibbs Energy Minimisation (GEM) approach and material can flow between these nodes by streams. In our model, the furnace is divided into a number of zones, e.g. a slag zone, metal zone etc. These zones are represented by nodes in a flowsheet, with mass flow between the nodes. Therefore, the chemistry in the reactor nodes is modelled by the GEM, while the mass transfer is handled by flow between the zones. It is thus possible to model the furnace without solving a large number of rate parameters for individual elements.

Late Quaternary landscapes of unglaciated Beringia were largely shaped by ice-wedge polygon tundra. Ice Complex (IC) strata preserve such ancient polygon formations. Here we report on the Yukagir IC from Bol'shoy Lyakhovsky Island in northeastern Siberia and suggest that new radioisotope disequilibria (230Th/U) dates of the Yukagir IC peat confirm its formation during the Marine Oxygen Isotope Stage (MIS) 7a–c interglacial period. The preservation of the ice-rich Yukagir IC proves its resilience to last interglacial and late glacial–Holocene warming. This study compares the Yukagir IC to IC strata of MIS 5, MIS 3, and MIS 2 ages exposed on Bol'shoy Lyakhovsky Island. Besides high intrasedimental ice content and syngenetic ice wedges intersecting silts, sandy silts, the Yukagir IC is characterized by high organic matter (OM) accumulation and low OM decomposition of a distinctive Drepanocladus moss-peat. The Yukagir IC pollen data reveal grass-shrub-moss tundra indicating rather wet summer conditions similar to modern ones. The stable isotope composition of Yukagir IC wedge ice is similar to those of the MIS 5 and MIS 3 ICs pointing to similar atmospheric moisture generation and transport patterns in winter. IC data from glacial and interglacial periods provide insights into permafrost and climate dynamics since about 200 ka.

Provenance studies on tea (Camellia sinensis) are an important tool to reconstruct the origin of tea products. This thesis explores the potential of using solely the ionome (main and trace element concentrations) of tea shoot tips for provenance studies. The emphasize of the thesis is to find element subcompositions which are robust in respect to the various parameters of tea cultivation and production, such as the area, their soils, soil fertilizer and applications of foliar sprays, tea cultivars, plucking/harvesting techniques, manufacturing or leaf grade of the processed tea. For specific discrimination tasks these robust subcompositions can be combined with element subcompositions which are sensitive to one or several tea cultivation and production parameters. The data set consists of ca. 300 leaf and processed tea samples and ca. 130 soil samples. The sampling areas are located in Darjeeling, Assam and Nilgiris in India, in Paraná and São Paulo in Brazil and in Uji and Shizuoka in Japan. All samples, plants and soils, had been treated with four acid digestion methods with HNO3, HCl, HClO4 and HF to achieve a total dissolution. The sample solutions had been analyzed by ICP-MS and ICP-OES. The element concentrations of the leaf and processed tea samples had been corrected for adhering (soil) particles. Hence, all statistical analysis are based on the corrected concentrations values of Al, Ba, Ca, Cd, Co, Cr, Cs, Cu, Fe, K, La, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Sc, Sr, Tl, Y and Zn. The element concentrations are converted into log-ratios by additive, centered or isometric log-ratio transformations prior to statistical analysis to avoid spurious correlations and to enhance the signal-noise ratio for e.g. the trace elements concentrations. The comparison of the geochemical composition of topsoils, subsoils, mature leaves, shoot tips and processed tea samples is used to establish for each element a qualitative index of robustness with respect to cultivation and production parameters. The elements with a high robustness are considered as very suitable for a provenance analysis without further knowledge about the tea samples. The thesis exemplary shows that with already small element subcompositions a good discrimination by geographical origin is possible if the elements are chosen in terms of their suitability for provenance studies of tea including their sensitivity in respect to specific parameters. The geological source rocks of the tea plantations is one of the major factors for discrimination of tea origin.

We present Traveling-Wave Electron Acceleration (TWEAC), a novel compact electron accelerator scheme based on laser-plasma acceleration. While laser-plasma accelerators provide multi-GeV electron beams today, the acceleration to higher energies is limited. The sub-luminal group-velocity of plasma waves let electrons outrun the accelerating field.

In order to control the speed of the accelerating plasma cavity, TWEAC utilizes two pulse-front tilted laser pulses whose propagation directions enclose an acute angle. The accelerating cavity is created along their overlap region in the plasma and can move at the vacuum speed of light. The oblique laser geometry enables to constantly cycle different laser beam sections through the interaction region, hence providing quasi-stationary conditions of the wakefield driver. Thus, TWEAC offers constant acceleration without a dephasing electron beam while avoiding usual laser pump depletion within the interaction region. This opens the way for electron energies beyond 10 GeV, possibly towards TeV class electron beams, without the need for multiple laser-accelerator stages.

In this poster we study the energy efficiency of TWEAC compared to LWFA. We find that for low-angle TWEAC setups, it is possible to accelerate high-charge bunches with laser to electron beam energy efficiencies close to 50%, which exceeds energy efficiencies typically attained with LWFA.

The HESEB (Helmholtz-SESAME soft X-ray beamline) project is an initiative by the Helmholtz Association of German Research Centers (HGF) to implement a new beamline at SESAME for scientific applications using soft X-ray spectroscopy techniques. The beamline design, procurement, and construction are being carried out by a consortium of the HGF centers DESY, FZJ, HZB, HZDR and KIT in collaboration with SESAME.

The new beamline will be available for the SESAME user community within the four year project duration. It will allow for a large number of top-class scientific applications and provide new cooperation potentials with German and international research groups. The beamline is based on a variable-polarization undulator and a plane-grating monochromator covering an energy range 80 - 2000 eV. The optical design and the technical specifications have been completed and a call for tender procedure is ongoing. It is expected that the beamline will see first light in summer 2021.

During the course of the project, the main goals to be achieved are (i) the construction and commissioning of the beamline at SESAME with a chamber for cultural heritage applications using spatially resolved soft X-ray fluorescence, (ii) the leveraging of additional contributions from the SESAME member countries to promote the build-up of international user consortia and to secure funding for experimental endstations and additional instrumentation, (iii) the training of SESAME staff at participating Helmholtz centers to enable reliable operation of the beamline by local staff, and (iv) the fostering of the establishment of a broad user community of HESEB from the SESAME member states through training, workshops, and schools. The first soft X-ray HESEB science workshop will take place in Istanbul beginning of 2020.

The qda() function from package 'MASS' is extended to calculate a weighted linear (LDA) and quadratic discriminant analysis (QDA) by changing the group variances and group means based on cell-wise uncertainties. The uncertainties can be derived e.g. through relative errors for each individual measurement (cell), not only row-wise or column-wise uncertainties. The method can be applied compositional data (e.g. portions of substances, concentrations) and non-compositional data.

Traveling-Wave Thomson-Scattering (TWTS) is a novel Thomson scattering geometry which allows for orders of magnitude higher photon yields than classic head-on Thomson sources. TWTS thereby remains compact and provides narrowband and ultra-short ultraviolet to γ-ray radiation pulses just as classic Thomson sources. Even the realization of optical free-electron lasers is possible with the TWTS geometry since it provides both optical undulators with thousands of periods needed to microbunch the electron beam and a reduction of electron beam quality requirements compared to classic Thomson scattering to a level technically feasible today. TWTS employs a side-scattering geometry depicted in fig. 1. Laser and electron propagation direction of motion enclose the interaction angle ϕ. Tilting the laser pulse front with respect to the wave front by half the interaction angle ensures continuous overlap of electrons and laser pulse over the whole laser pulse width while the laser pulse crosses the electron beam trajectory. In this way the interaction length becomes controllable by the laser pulse width and independent of the laser pulse duration. Utilizing wide, petawatt class laser pulses for TWTS allows to realize thousands of optical undulator periods. The variability of TWTS with respect to the interaction angle can be used to control the radiation wavelength even for electron sources with fixed energy. For a fixed target wavelength on the other hand, the free choice of interaction angle enables control over electron beam quality requirements. Small interaction angle scenarios (ϕ∼10°) typically yield the best trade-off between requirements on electron beam quality, laser power and laser intensity stability. In the talk we will show that TWTS OFELs emitting extreme ultraviolet radiation are realizable today with existing technology for electron accelerators and laser systems. We detail an experimental setup to generate the tilted TWTS laser pulses which aims at compactness and provides focusing of these high-power pulses and compensation of dispersion accompanying pulse-front tilts. The method presented for dispersion compensation is especially relevant when building high yield X- and γ-ray sources in large interaction angle setups of TWTS.

Laser wakefield accelerators (LWFA) feature unique electron bunch characteristics, namely micrometer beam size with duration ranging from a few fs to tens of fs. Precise knowledge of the longitudinal profile of such ultra-short electron bunches is essential for the design of future table-top x-ray light-sources.
Spectral measurements of broadband transition radiation from LWFA electron bunches passing through a metal foil are especially promising for non-destructively analyzing ultrashort longitudinal bunch characteristics with single-shot capability.

Our broadband, single-shot spectrometer combines the TR spectrum in UV/VIS (200-1000nm), NIR (0.9-1.7μm) and mid-IR (1.6-12μm). A complete characterization and calibration of the spectrometer have been done with regard to wavelengths, relative spectral sensitivities, and absolute photometric sensitivity. Our spectrometer is able to characterize electron bunches with charges as low as 1 pC and resolve time-scales from 0.4 to 40 fs. In addition, complementary data on the transverse bunch profile is provided by simultaneously imaging the CTR in the far- and near-field.

We present recent experimental results of different LWFA injection mechanisms, such as self-truncated ionization-injection and self-injection. By analyzing the transition radiation spectra and reconstructing electron bunch profiles including error analysis, we determine electron bunch profiles and peak currents of the respective injection regimes. In addition to bunch durations and peak currents, we show sub-fs beam micro-structures and systematic experimental scans of the nitrogen doping concentration for ionization-induced injection.

While laser-plasma accelerators provide multi-GeV electron beams today, the acceleration to higher energies is limited. The sub-luminal group-velocity of plasma waves let electrons outrun the accelerating field. We present Traveling-Wave Electron Acceleration, a novel compact laser-plasma accelerator scheme which circumvents the LWFA constraints of electron beam dephasing, laser pulse diffraction and depletion.

For controlling the speed of the accelerating plasma cavity, TWEAC utilizes two pulse-front tilted lasers whose propagation directions enclose a configurable angle. The accelerating cavity is created along their overlap region in the plasma and can move at the vacuum speed of light. Such guiding-structure-free, lateral coupling of lasers into the plasma allows the field within this overlap region to be continuously replenished by the successive parts of the laser pulse. Supported by 3D particle-in-cell simulations, we show that this leads to quasi-stationary acceleration conditions for electron bunches along the total acceleration length, such that TWEAC is in principle scalable to arbitrarily long acceleration stages.

We discuss scaling laws and detail experimental design considerations. We find that for low-angle TWEAC setups, it is possible to accelerate nanocoulomb-class bunches with laser to electron beam energy efficiencies close to 50%, thus exceeding energy efficiencies typically attained with LWFA.

The hybrid L|PWFA acceleration scheme combines laser- (LWFA) with plasma-wakefield acceleration (PWFA) to provide an ultra-compact, high-brightness electron source. Recently, the acceleration of a witness bunch using this hybrid scheme was demonstrated at HZDR. In this talk, we present recent start-to-end simulations, that accompanied the experimental campaign, and provided fundamental insights into the injection and acceleration process of this novel, compact accelerator. These accompanying simulations were performed using the 3D3V particle-in-cell code PIConGPU. A significantly enhanced agreement between theoretical predictions and experimental measurements could be achieved by resembling the experiment to a very high degree. Modeling the geometry, density distributions, laser modes, and gas dopings as measured in the experiments provided good comparability between experiment and simulation. With that degree of agreement, the wealth of information provided by the in-situ data analysis of PIConGPU provided insight into the plasma dynamics, otherwise inaccessible in experiments. The talk will not only focus on explaining the fundamental physical process behind this hybrid scheme but will further elaborate on the essential details that produce the quasi-monoenergetic witness bunches seen in experiment. Furthermore, we will discuss the associated challenges in maintaining numerical stability and experimental comparability of these long-duration simulations.

Innovation in raw material exploration relies on efficient and non-invasive technologies. Spectroscopy based methods have proven great potential to deliver instant and spatially continuous information on the composition of an investigated surface. Several studies successfully applied laser-induced fluorescence (LIF) for rare-earth element (REE) identification in natural rocks. However, the diagnostic assignment of detected emission lines remains a complex task, because of the highly variable composition of natural rocks. It needs a transfer of the profound knowledge from the field of applied physics and synthetic materials to the natural rock material under investigation. The evaluation of measured spectra and robust assignment of REEs requires reference data, yet usually based on tables of published emission lines, while data of complete reference spectra are not available.
We present a library of reference spectra for all luminescent rare-earth elements using the Smithsonian rare-earth phosphate standards for electron microprobe analysis. We employ laser-induced fluorescence at three commonly used laser wavelengths (325 nm, 442 nm, 532 nm) to acquire reference spectra for REE phosphate minerals in the visible to near-infrared spectral range (350 – 1080 nm). Excitation at all three laser wavelengths yielded spectra with distinct REE-related emission lines for EuPO4, TbPO4, DyPO4 and YbPO4. Lower energy laser excitation at 442 nm showed successful especially for suppressing non-REE-related broadband defect emission. Resulting REE-reference spectra include those from PrPO4, SmPO4 and ErPO4. For NdPO4 and HoPO4 most efficient excitation was achieved with 532 nm. The diagnostic emission lines of GdPO4 lie outside the detection range and none of the three laser wavelengths was appropriate for TmPO4 excitation.
Our results demonstrate the suitability of LIF for REE detection and especially the possibility of selective element excitation. Our reference spectra provide the full spectral information at high resolution (0.13nm) as a basis for an improved evaluation of REE-bearing natural rocks allowing for data analysis of emission line positions, emission line intensity ratios and splitting into emission line sub-levels. The spectral library data support the use of LIF for REE analysis in natural samples and its application in raw material exploration.

This keynote presentation introduces the concept of instrumented flow followers for determination of hydrodynamic parameters in large process vessels. Instrumented flow followers are medium size particles that drift with the flow in a vessel. They actively adjust buoyancy with an electromechanical mechanisms and comprise sensors for temperature, pressure, acceleration and further parameters. Furthermore, novel concepts of data transfer, communication and positioning are being presented.

Die chemische Industrie steht derzeit, wie viele andere Industriebereiche, vor den Herausforderungen einer Digitalisierung der Produktion. Sie ist der Schlüssel für die Flexibilisierung von Prozessen und Anlagen, für die Verkürzung von Produkteinführungszeiten sowie für den Zuschnitt der Produktion auf wechselnde Nachfrage und kürzere Produktlebenszyklen. In einer vernetzten Welt werden Informationen über Rohstoffe, Energieträger und Marktbedingungen instantan verfügbar. Sie können damit direkt in Prozessabläufe einfließen und bei der Erstellung von Marktprognosen helfen. Allerdings ergeben sich für die Digitalisierung von Produktionsprozessen in der chemischen Industrie besondere Herausforderungen durch ein oftmals sehr produktspezifisches Anlagendesign sowie die komplexe stoffliche und energetische Verkettung von Grundoperationen.
Die Messtechnik und Sensorik spielt neben der intelligenten Datenverarbeitung eine Schlüsselrolle für die Digitalisierung. Flexiblere Anlagen benötigen Sensorik zur Überwachung des Anlagenzustandes, zur Früherkennung nicht bestimmungsgemäßer Betriebszustände sowie für eine bedarfsgerechte Wartung. Neben der Zustandsüberwachung ist ebenfalls eine verbesserte Sensorik für die Erfassung von stoffbezogenen Daten essenziell, um Einbußen der Produktqualität, etwa durch Verunreinigungen und Spurstoffe, schwankende Eduktzusammensetzungen oder degradierte Katalysatoren frühzeitig zu erkennen. Dafür geeignete spektroskopische Messtechniken sind heute fast immer noch ausschließlich für den Laborbereich verfügbar und müssen auf die Prozessebene übertragen werden.
Für diese Herausforderungen ist die in heutigen Prozessanlagen vorhandene betriebliche Instrumentierung sowohl bezüglich der von ihr erfassten Informationen als auch bezüglich der von ihr bereitgestellten Schnittstellen und Datenformate nicht ausreichend. Eine Weiterentwicklung der Prozessmesstechnik und Prozessanalysentechnik in Richtung der Erfassung sekundärer Prozess-parameter, einer intelligenten multimodalen Sensordatenverarbeitung, standardisierter digitaler Schnittstellen sowie Sensorintelligenz ist unabdingbar. Schließlich ist beim verstärkten Einsatz neuer Sensorik der Sensorrobustheit, der Eigensicherheit im Prozess sowie der einfachen, auch nachträglichen oder temporären, Installierbarkeit von Sensoren in großen Anlagen und rauen Prozessumgebungen Rechnung zu tragen.
Da die Entwicklung neuer und verbesserter Messtechnik und Sensorik grundlegend aus verschiedenen Richtungen gedacht werden muss, haben sich Akteure aus verschiedenen Branchen zusammengetan und dieses Positionspapier erstellt. Es basiert auf einer grundlegenden Analyse des Ist-Stands sowie des Bedarfs der Industrie, die unter anderem auf einem eigens dafür durchgeführten Workshop mit Sensorentwicklern, Anlagenherstellern sowie Anlagenbetreibern am 18. Juni 2019 bei der DECHEMA in Frankfurt a. M. diskutiert wurden. Diese Aktivitäten wurden maßgeblich von der Initiative Wanted Technologies der ProcessNet sowie dem AMA Verband für Sensorik und Messtechnik e.V. initiiert.

An existing pyrometallurgical process for tantalum and niobium recovery, mainly from low grade pyrometallurgical residues, was investigated. Series of melting experiments were carried out in a pilot-scale electric arc furnace to study how the amount, the grain size and the way of feeding affect the activity of carbon as a reducing agent. During the pyrometallurgical treatment refractory metals such as tantalum and niobium are reduced to their carbide form and enriched in the molten iron-based metal phase. The cooled down slag and metal phase were analysed to investigate thermodynamic and kinetic conditions of the carbide formation. FACT Sage simulations were also used to investigate the material system in state of thermodynamic equilibrium. Results show that mass transfer and kinetics may play an important role if compared to equilibrium analyses using FACT Sage.

The complexity of metal and material mixtures in products
Simulation-based quantification of the resource efficiency of very large - Circular Economy (CE) systems
Various industrial examples for footprinting the CE e.g.
Copper rock to metal – exergy dissipation of the system
PV life cycle linked to energy system: exergy dissipation in the system
Zinc and lead processing systems
Product design for circularity for OEMs (mobile, LED, laptops etc.)
Battery recycling,
Water systems optimization, and
…many more, also developed during my time @ Outotec, also in client solution development, sales, etc.
Challenges?
Too many not yet accepting the above state-of-the-art in the CE discussion, leading to critical and sub-optimal discussions, policy, etc.

Circular economy's (CE) noble aims maximize resource efficiency (RE) by, for example, extending product life cycles and using wastes as resources. Modern society's vast and increasing amounts of waste and consumer goods, their complexity, and functional material combinations are challenging the viability of the CE despite various alternative business models promising otherwise. The metallurgical processing of CE-enabling technologies requires a sophisticated and agile metallurgical infrastructure. The challenges of reaching a CE are highlighted in terms of, e.g., thermodynamics, transfer processes, technology platforms, digitalization of the processes of the CE stakeholders, and design for recycling (DfR) based on a product (mineral)-centric approach, highlighting the limitations of material-centric considerations. Integrating product-centric considerations into the water, energy, transport, heavy industry, and other smart grid systems will maximize the RE of future smart sustainable cities, providing the fundamental detail for realizing and innovating the United Nation's Sustainability Development Goals.

Circular Economy (CE)
Digitalization in the metallurgical industry within the CE system
Metallurgical reactor technology
Design for recycling
Various literature and other detail

Ein Abschied ist zugleich ein Neuanfang. Der Ausstieg aus den fossilen Energieträgern ist klimapolitisch überfällig. Das aktive Phase-Out des fossilen Erdöls erfordert zugleich einen Einstieg, ein aktives Phase- In von noch mehr Metallen. Beides, Einstieg und Ausstieg, zusammenzuhalten ist der Schwerpunkt unserer Veranstaltung.

Auch das postfossile Zeitalter braucht Energie. Der Ersatz für die fossilen Energieträger beim Übergang zu regenerativen Energien sind die mehr als ausreichenden Energieströme von der Sonne. Zukünftig primäre Bedeutung wird daher die Elektroenergie haben. Für die Energiewende brauchen wir mehr Metalle: Ob klassische Basismetalle wie Kupfer oder etwa Seltenerdmetalle wie Neodym für die Permanentmagneten moderner Windkraftanlagen. Auch die Mobilitätswende erfordert eine zunehmende Elektrifizierung des motorisierten Straßenverkehrs, sei es direktelektrisch oder mit Wasserstoff / Brennstoffzelle. Mit der Digitalisierung kommt nochmals eine weitere Dimension an Metallbedarf auf uns zu. Metalle sind die Voraussetzung für die Energiewende, die Mobilitätswende und die digitale Transformation. Dazu braucht es alle Metalle im Periodensystem – wir sind im „All Metals Age“ angekommen.

Es geht dabei nicht nur um Lithium, um Kobalt, wozu gelegentlich Meldungen aufgrund von Menschenrechtsverletzungen und Auseinandersetzungen im Kongo bei uns aufschlagen. Oder nur um Seltenerdmetalle, die im Handelskonflikt zwischen den USA und China eine starke Stellung Chinas signalisieren. Wir brauchen ein umfassendes Problemverständnis für die Metalle.

Der klimapolitisch überfällige Übergang ist somit, recht betrachtet, einer vom Zugriff auf einen Bodenschatz zu einem anderen. Der Unterschied in den Eigenschaften dieser beiden Typen von Bodenschätzen wird die zukünftige Geschichte der Menschheit prägen, sowohl die wirtschaftliche als auch die politische. Im Gegensatz zum fossilen Erdöl können wir aus der Nutzung von Metallen nicht aussteigen.

The presentation deals with the results generated in the frame of the German-Polish research project NOMECOR. The technical feasibility of the combined utilization of valueable elements and mineral compartments of tailing material from the flotation pond Zelazny Most could be proven. The suggested process steps could, however, not be implemented due to economic constraints. The project consortium nevertheless managed to suggest an implementation of the novel processing technologies in a lighter, more simple type.

Processing residues and waste rock are prominent features of mining activities. Especially flota-tion tailings lead to huge land consumption and are a potential source of environmental hazards. In addition, their geotechnical handling is very challenging. On the other hand, the tailings often comprise remains of valuable metals, which more and more came into the focus of scientific investigations and technology developments due to decreasing metal concentrations in the raw ores. G.E.O.S. engaged in the metal recovery from tailings in the frame of several projects with different partners. The scientific approach in these projects concentrated on combination of metal recovery with the removal of contaminants. In the ideal scenario the residues from these approaches can be utilized for underground backfilling or dump construction. So these projects can be regarded as a holistic approach for remediation. Based on laboratory scale results a pilot plant for metal recovery from flotation tailings was developed which comprises several mod-ules.
The first project concentrated on bioleaching of flotation tailings material from an old Freiberg Pb-Zn-ore processing facility (closed in 1968) by an airlift reactor (100 L). As a result, up to 90 % In and almost 100 % Zn were leached from the material which showed initial concentra-tions of 14 ppm In and 10,000 ppm Zn. In another project together with Polish partners an am-moniac leaching process for processing of carbonatic tailings material from Cu concentrate flota-tion was developed. By leaching untreated homogenized tailings material a Cu recovery of 45 % was achieved. After pre-concentration of the material through re-grinding and flotation the re-covery could even be increased to 85 – 90 %.
Motivated by these results a pilot plant was designed consisting of three modules: a) leaching module, b) metal recovery module and c) environmental module. The leaching module compris-es a 1.5 m³ airlift reactor, one decanter centrifuge for effective solid/liquid separation and sever-al stirring and storage tanks needed for continuous process operation and for washing the leach-ing residue. In the metal recovery module (feed 5-10 L/h) are integrated as main processing stages: solvent extraction, absorber columns (activated carbon, IX resin) and one electrolysis cell. Iron can be precipitated as schwertmannite or ferrihydrite (biological/chemical oxidation). The environmental module is designed as classical precipitation, flocculation and sedimentation unit for treatment of remaining liquids from the metal recovery module to meet the discharge parameters. The pilot plant is currently under construction. The commissioning is planned for May 2019.

The harmony and complexity of metal and material mixtures: Their value
Simulation-based quantification of the resource efficiency of very large - Circular Economy (CE) systems
Various industrial examples for understanding very large CE systems:
A policy brief informing society: Lead key enabler of the circular economy
Car recycling: Design for recycling SEAT
PV resource life cycle linked to energy system: Exergy dissipation in large systems
Various EU & EIT Rawmaterials projects as well as BMBF and B2B:
PreMa: Low CO2 production of FeMn, incl. solar heat
GUCCIS: Product design for circularity
B2B: Fairphone
Circular by Design: BMBF Germany
Submitted project: SiSal Pilot
INFACT: EU project

We present the results of an experiment on laser-driven shock waves performed at the Prague Asterix Laser system (PALS), where the fundamental frequency of the laser (1315 nm) is used to launch a strong shock in planar geometry. The experiment aims to characterize both shock waves and hot electrons generated at intensities of ’ 1016 W=cm2 . It is shown that, in these interaction conditions, hydrodynamics is strongly impacted by noncollisional mechanisms, and the role of the hot electrons, generated by parametric instabilities, is essential in determining shock dynamics.

Understanding and appropriate modelling of geochemical processes is essential for predicting the contaminant transport in groundwater systems and, therefore, important in many application areas such as groundwater prediction, environmental remediation, or disposal of hazardous waste. One important natural retardation process is sorption on mineral surfaces of rocks or sediments. In order to treat the radionuclide sorption processes in natural systems more realistically, we developed the smart Kd-concept (www.smartkd-concept.de) to predict variations in sorption as consequence of changing physicochemical conditions which have to be considered in long-term safety assessments for radioactive waste repositories (Noseck et al., 2012, 2018; Stockmann et al., 2017).
In this presentation, we describe the fundamental strategy of the smart Kd-concept to calculate distribution coefficients (referred to as smart Kd-values) for a wide range of important environmental parameters. This mechanistic approach mainly based on surface complexation models and is combined with the “Component Additivity” approach to describe a natural system close to reality. This bottom-up approach based on the principle that the sorption of contaminants can be determined based on the competitive mineral-specific sorption of dissolved species on surfaces. Therefore, a full thermodynamic description of both the aqueous, solid and interface reactions is required. Using the geochemical speciation code PHREEQC (Parkhurst and Appelo, 2013), multidimensional smart Kd-matrices are computed as a function of varying (or uncertain) input parameters such as pH, ionic strength, concentration of competing cations and complexing ligands, e.g. calcium (Ca) and dissolved inorganic carbon (DIC). On the one hand, sensitivity and uncertainty statements for the distribution coefficients can be derived. On the other hand, smart Kd-matrices can be used in reactive transport codes (see abstract Noseck et al. 2020). This strategy has various benefits: (1) rapid computation of Kd-values for large numbers of environmental parameter combinations; (2) variable geochemistry is taken into account more realistically; (3) efficiency in computing time is ensured, and (4) uncertainty and sensitivity analysis are accessible. It is worth mentioning that the basic methodology described here can be transferred to any other transport code relying on conventional distribution coefficients as well as to any other complex natural site.
Results of a case study (serving as a comprehensive proof-of-concept) for a typical sedimentary rock system in Northern Germany as natural geological barrier for a deep geological repository site showed that the smart Kd approach goes considerably beyond the conventional concepts. We can illustrate that constant Kd values (see for U(VI) in Fig. 1, right, green line) previously used in transport simulations are a crude assumption, as in reality they rather range over several orders of magnitude. Moreover, with the results from the sensitivity analyses (SA) (Becker, 2016), the most important input parameters influencing the radionuclide retardation can be identified (key parameters of the model). The calculated sensitivity indices allowed us to assess the most and less sensitive parameters. From the visualized smart Kd matrix for U(VI) (Fig. 1, left) it is obvious that mainly the pH value and the DIC influences the sorption of U(VI) under the given conditions. SA is a useful means for reducing the complexity of a geochemical model by focusing on the most important input parameters.

We performed experiments with the Petawatt beam of the Dresden laser acceleration source Draco to investigate the feasibility of controlled volumetric tumour irradiations with laser-accelerated protons. Therefore, a beamline of two pulsed solenoid magnets was implemented to efficiently capture and shape the beam, which was then analysed by a comprehensive suite of detectors (ionization chamber, scintillator, radiochromic film, ..).
We extensively studied how to manipulate and match lateral and depth dose profiles to the desired application and target. These were assisted by benchmark experiments at a conventional accelerator to further characterize the ion-optical properties of the solenoids and to investigate potential distortions of the transported proton beam.
With the characterized beamline first proof-of-principle irradiation studies of volumetric normal and tumour tissue samples have been performed successfully. To advance to full scale irradiation experiments, a higher mean dose rate is necessary to deliver high absolute dose values via multiple bunches (dose control) in short times (~min). Current limitations are the low repetition rate of the beamline and its long cooldown times. Therefore, we developed a novel, actively cooled pulsed solenoid, to be implemented in the beamline, enabling complex irradiation studies with high repetition rates and consequently high mean dose rates.

The complexity of metal and material mixtures in products
Simulation-based quantification of the resource efficiency of very large - Circular Economy (CE) systems
Various industrial examples for understanding very large CE systems e.g.
A policy brief informing society: Lead key enabler of the circular economy
PV life cycle linked to energy system: exergy dissipation in the system
Car recycling – design for recycling
Challenges?

für diesen Vortrag hat keine inhaltliche Kurzfassung vorgelegen

Si nanopillars for the fabrication of vertical nanowire gate-all-around Single Electron Transistors [1], have been irradiated with Si++, Pb+, Pb++, Au +, Au++, Au2 +, and Au3 + ions accelerated by 30 kV. A FIB of mass separated ions, extracted from a Liquid Metal Alloy Ion Source [2], has been scanned over regular arrays of Si nanopillars of different diameters and pillar distances. The irradiations have been performed at RT and 400∘C. Different morphological changes of the pillars like thinning, height reduction, tilting etc. have been observed which can be attributed to ion erosion (sputtering), impact-induced viscous flow or even transient nanosecond-scale melting [3]. The pillars were imaged by AFM, SEM, TEM and HIM. 3D Monte Carlo
simulations [4] of ion and recoil trajectories based on the Binary Collision Approximation and Molecular Dynamics calculations have been carried out in order to discriminate the dominating processes.
[1] EU project Ions4SET, Horizon 2020 grant No. 688072
[2] L.Bischoff, et al., Appl. Phys. Rev. 3 (2016) 021101
[3] C. Anders, K.-H. Heinig, H. Urbassek, Phys. Rev. B87 (2013) 245434
[4] W. Möller,NIM B322 (2014) 23

UHDpulse - Metrology for advanced radiotherapy using particle beams with ultra-high pulse dose rates is a recently started European Joint Research Project with the aim to develop and improve dosimetry standards for FLASH radiotherapy, very high energy electron (VHEE) radiotherapy and laser-driven medical accelerators. This paper gives a short overview about the current state of developments of radiotherapy with FLASH electrons and protons, very high energy electrons as well as laser-driven particles and the related challenges in dosimetry due to the ultra-high dose rate during the short radiation pulses. We summarize the objectives and plans of the UHDpulse project and present the 16 participating partners with their skills and roles.

The complexity of metal and material mixtures in products
Simulation-based quantification of the resource efficiency of very large Circular Economy (CE) systems
Various industrial examples for understanding very large CE systems e.g.
A policy brief informing society: Lead key enabler of the circular economy
PV life cycle linked to energy system: exergy dissipation in the system
Car recycling – design for recycling
Many more, also developed during my time @ Outotec, also in client solution development, sales, etc.:
Copper rock to metal – exergy dissipation of the system
Battery recycling
Zinc and lead processing systems
Product design for circularity for OEMs (mobile, LED, laptops etc.)
Water systems optimization e.g. on concentrator plants
Challenges?
Background information

The importance of metals in society /
The fundamental role of metals in a circular society /
Metallurgical infrastructure criticality in a circular society – recovering the minor elements /
Our actions as industry?

The complexity of metal and material mixtures in products
Simulation-based quantification of the resource efficiency of very large - Circular Economy (CE) systems
Applying the tools of process metallurgy to quantify CAPEX and OPEX of CE system
Various industrial examples for footprinting the CE e.g.
PV life cycle linked to energy system: exergy dissipation in the system
Various other examples among many:
Copper rock to metal – exergy dissipation of the system (industry)
Product design for circularity for OEMs (mobile, LED, laptops etc.)
Water systems optimization (industry)
Zinc and lead processing systems (industry)
Challenges?

INTRODUCTION
Depositional records of atmospheric cosmogenic radionuclides play an important role in the reconstruction of fluctuations of the solar activity over millennial timescales (Beer, 2000). However, sedimentary ¹⁰Be records reflect partly the local depositional conditions such as precipitation patterns. Therefore, a cross-check of ¹⁰Be records obtained from different geographical locations with distinct precipitation regimes is important. To meet this demand, as polar ice cores proved to be invaluable archives of atmospheric ¹⁰Be deposition, increasing scientific interest turned to ¹⁰Be records of mid-latitude glaciers (Inceoglu et al., 2016). Conversely, while presently surface glaciation is mostly absent at mid-latitudes, subterranean glaciation (i.e., ice caves) is a common feature, even on low-elevation karstic areas. Once it forms, cave ice can preserve the deposition record of ¹⁰Be similarly to surface ice bodies, so it has the potential to be a useful complementary archive providing comparable records of past atmospheric ¹⁰Be deposition.
We present here a record of atmospheric ¹⁰Be locked in the millennial old ice deposits from Scărișoara Ice Cave, Romania. To our knowledge, our project is the very first in measuring atmospherically-produced ¹⁰Be in cave ice deposits.

SAMPLING STRATEGY and METHODOLOGY
A ~6 m long, 10 cm diameter ice core was extracted from the ice block of the Scărișoara Ice Cave (Apuseni Mts, Romania, Fig. 1) in 2015 in segments each between 5 and 30 cm long. The outer surface of the core was immediately cleaned in the field using sterilized plastic knives, subsequently wrapped in clean plastic bags and stored at temperatures between -20°C and -40°C prior to analysis. The ice cores were transported frozen to the Cosmogenic Nuclide Sample Preparation Laboratory in Budapest (http://www.geochem.hu/kozmogen/Lab_en.html) in 2018. Nine ice core sections, each weighing ~300 g, were selected for a pilot study. Radiochemical sample processing including addition of defined amounts of stable ⁹Be followed the methodology of Zipf et al. (2016) and was carried out at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). Accelerator Mass Spectrometry (AMS) measurements of the ¹⁰Be/⁹Be ratio of the samples were performed also there. Data were normalized to SMD-Be-12 (Akhmadaliev et al., 2013), which is traceable to the NIST4325 standard.
The processing and measurement of these pilot samples was successful: all samples provided measurable and distinct ¹⁰Be/⁹Be ratios. The performance of five out of nine samples was excellent. Although the chemical yield of four samples was lower than expected (except for one sample) uncertainties remained below 5% (range between 2.3 and 5.1%; mean 3.5%).
An additional set of nine samples was selected for analysis in 2019, with the aim of using a slightly modified radiochemistry method to achieve increased and more stable chemical yield for all samples and to provide more details of the variations of atmospheric ¹⁰Be concentrations along the core. This sample set was radiochemically processed by the same people but at the University of Vienna. These samples were investigated by AMS out at the Vienna Environmental Research Accelerator (Steier et al., 2019). The data were again normalized to the secondary standard SMD-Be-12 to allow direct comparability between the two datasets.
The age of the ice core was determined by transferring the depth-age model of the Perșoiu et al. (2017) record, based on 26 ¹⁴C ages, to the present core. Four ¹⁴C measurements of this new core were used as anchor points for the older chronology. The chronological framework has been assigned to the cave ice derived ¹⁰Be results following the synchronization of the depth-scales of the two cores.

RESULTS and DISCUSSION
Due to successfully-improved chemical preparation, the chemical yield could be increased for all samples, hence, leading to smaller overall uncertainties of the ¹⁰Be data of the second sample set (1.9-3.6% (mean 2.7%). The measured ¹⁰Be/⁹Be ratio of the samples and processing blanks are in the same range for both sample sets (Fig. 2).
The ¹⁰Be concentrations range from (0.52±0.02)×10⁴ at/g_ice to (4.17±0.16)×10⁴ at/g_ice in the combined dataset (Fig. 2). This concentration range is comparable to those found in polar ice cores (Berggren et al., 2009, von Albedyll et al., 2017) but slightly lower than in the high-elevation Asian mountains (Inceoglu et al., 2016).
Based on the ¹⁴C measurements, the maximum age of the 6 m core is estimated to be 900 years. The ¹⁰Be concentrations of the studied section covers the upper 1.5 m of the ice core and corresponds to the ~1630 AD to ~1850 AD time interval.
The main trend in the cave ice derived ¹⁰Be concentration mirrors quite well the ¹⁰Be concentration profiles obtained from polar ice cores for the same period (von Albedyll et al., 2017, Berggren et al., 2009). The ¹⁰Be concentration peak (3.96±0.20)×10⁴ at/g_ice, Fig. 2) in the Dresden data found at the depth range of ~97-103 cm below surface corresponding to the late 1680s AD might reflect the Maunder Minimum documented as peak concentration both in the Akademii Nauk ice core (von Albedyll et al., 2017) and the NGRIP ice core (Berggren et al., 2009).
The data looks very promising, but further data evaluation and interpretation is still needed.

ACKNOWLEDGEMENTS
This research was funded by the National Research, Development and Innovation Office of Hungary grant OTKA FK 124807 (ZsRR), and UEFISCDI Romania through grant number PN-III-P1-1.1-TE-2016-2210 (AP). Parts of this research were carried out at the Ion Beam Centre (IBC) at the Helmholtz-Zentrum Dresden-Rossendorf e. V., a member of the Helmholtz Association. AMS measurements at VERA facility (University of Vienna) were supported by the Radiate Transnational Access 19001687-ST. This is contribution No.71 of the 2ka Palæoclimatology Research Group.

References
von Albedyll, L., Opel, T., Fritzsche, D., Merchel, S., Laepple, T., Rugel, G. 2017. ¹⁰Be in the Akademii Nauk ice core – first results for CE 1590–1950 and implications for future chronology validation. Journal of Glaciology 63, 514-522.
Akhmadaliev et al. 2013. The new 6 MV AMS-facility DREAMS at Dresden. Nucl. Instr. and Meth. Phys. Res. B 294, 5–10.
Beer, J. 2000. Long-term indirect indices of solar variability. Space Science Reviews 94 (1-2), 53-66.
Berggren et al., 2009. A 600-year annual ¹⁰Be record from the NGRIP ice core, Greenland. Geophysical Research Letters 36 (11), L11801.
Inceoglu, F., Knudsen, M. F., Olsen, J., Karoff, C., Herren, P. A., Schwikowski, M., Aldahan, A., Possnert, G. 2016. A continuous ice-core ¹⁰Be record from Mongolian mid-latitudes: influences of solar variability and local climate. Earth and Planetary Science Letters 437, 47-56.
Perşoiu, A., Onac, B.P., Wynn, J.G., Blaauw, M., Ionita, M., Hansson, M. 2017. Holocene winter climate variability in Central and Eastern Europe. Scientific Reports 7, 1196.
Steier, P., Martschini, M., Buchriegler, J., Feige, J., Lachner, J., Merchel, S., Michlmayr, L., Priller, A., Rugel, G., Schmidt, E., Wallner, A., Wild, E.M., Golser, R. 2019. Comparison of methods for the detection of 10Be with AMS and a new approach based on a silicon nitride foil stack. International Journal of Mass Spectrometry, 444, 116175.
Zipf, L., Merchel, S., Bohleber, P., Rugel, G., Scharf, A. 2016. Exploring ice core drilling chips from a cold Alpine glacier for cosmogenic radionuclide (¹⁰Be) analysis. Results in Physics 6, 78-49.

Focused Ion Beam (FIB) processing has been established as a well-suited and promising technique in R&D in nearly all fields of nanotechnology for patterning and prototyping on the µm-scale and below. Liquid Metal Alloy Ion Sources (LMAIS) represent an alternative to expand the FIB application fields beside all other source concepts. The need of light elements like B was investigated using various alloys. A promising solution was found in a Co31Nd64B5 based LMAIS which should be introduced in more detail. Beside Co ions as a ferromagnetic element and the rare earth element Nd especially B is interesting for special FIB applications with a best obtained resolution of about 30 nm so far.

The position of the pulp-froth interface in a flotation cell is an important parameter in froth flotation processes which needs to be controlled in situ. For this purpose, we employ a non-invasive technique, the so called ultrasound transit time technique (UTTT).
In UTTT, a transducer sends Ultrasound pulses of several MHz through the pulp. The pulses are reflected at the pulp-froth interface. The echoes are recorded by the emitting transducer and the time-of-flight is computed.
The vertical position of this interface is calculated by multiplying the time-of-flight with the speed of sound of the pulp. The latter is determined simultaneously by a second transducer, using a target plate which is placed at a known height in the pulp, simultaneously. Based on detailed measurements, the capabilities of the method are evaluated for a pulp-air and a pulp-froth interface in a lab-scale setup. The accuracy is found to be equal to better than 3%.

GaAs-based nanowires are attractive building blocks for the development of future (opto)electronic devices owing to their excellent intrinsic material properties, such as the direct band gap and high electron mobility. A pre-requisite for the implementation of novel functionalities on a single Si chip is the monolithic integration of the nanowires on the well-established Si complementary-metal-oxide-semiconductor (CMOS) platform with precise control of the nanowire growth process.
The self-catalyzed (Ga-assisted) growth of GaAs nanowires on Si(111) substrates using molecular beam epitaxy has offered the possibility to obtain vertical nanowires with predominant zinc blende structure, while potential contamination by external catalysts like Au is eliminated. Although the growth mechanism is fairly well understood, control of the nucleation stage, the nanowire number density and the crystal structure has been proven rather challenging. Moreover, conventional growth processes are typically performed at relatively high substrate temperatures in the range of 560-630 °C, which limit their application to the industrial Si platform.
This thesis provides two original methods in order to tackle the aforementioned challenges in the conventional growth processes. In the first part of this thesis, a simple surface modification procedure (SMP) for the in situ preparation of native-SiO_x/Si(111) substrates has been developed.
Using a pre-growth treatment of the substrates with Ga droplets and two annealing cycles, the SMP enables highly synchronized nucleation of all nanowires on their substrate and thus, the growth of exceptionally uniform GaAs nanowire ensembles with sub-Poissonian length distributions. Moreover, the nanowire number density can be tuned within three orders of magnitude and independent of the nanowire dimensions without prior ex situ patterning of the substrate. This work delivers a fundamental understanding of the nucleation kinetics of Ga droplets on native-SiOx and their interaction with SiO_x, and confirms theoretical predictions about the so-called nucleation antibunching, the temporal anti-correlation of consecutive nucleation events.
In the second part of this thesis, an alternative method called droplet-confined alternate-pulsed epitaxy (DCAPE) for the self-catalyzed growth of GaAs nanowires and GaAs/Al_xGa_1-xAs axial nanowire heterostructures has been developed. DCAPE enables nanowire growth at unconventional, low temperatures in the range of 450-550 °C and is compatible with the standard Si-CMOS platform. The novel growth approach allows one to precisely control the crystal structure of the nanowires and, thus, to produce defect-free pure zinc blende GaAs-based nanowires. The strength of DCAPE is further highlighted by the controlled growth of GaAs/Al_xGa_1-xAs axial quantum well nanowires with abrupt interfaces and tunable thickness and Al-content of the Al_xGa_1-xAs sections. The GaAs/Al_xGa_1-xAs axial nanowire heterostructures are interesting for applications as single photon emitters with tunable emission wavelength, when they are overgrown with thick lattice-mismatched In_xAl_1-xAs layers in a core-shell fashion. All results presented in this thesis contribute to paving the way for a successful monolithic integration of highly uniform GaAs-based nanowires with controlled number density, dimensions and crystal structure on the mature Si platform.

Demanding applications like radiation therapy of cancer are pushing the frontier of laser driven proton accelerators with controlled and well-defined proton beam properties. This talk will give an overview of recent achievements at the high-contrast high power laser source DRACO at HZDR. The laser system was recently upgraded by an additional Petawatt (PW) amplifier stage and new front end components finally providing high contrast pulses of >500 TW on target at 1 Hz pulse repetition rate. With the new PW beam line of Draco the feasibility of worldwide first controlled volumetric irradiation of a specifically developed tumor model, grown on the ears of nude mice with laser-accelerated protons are investigated. In order to efficiently capture and shape the divergent TNSA proton beam, a setup of two pulsed high-field solenoid magnets has been developed and applied. The talk will summarize results of the reliable generation of homogeneous depth dose distributions and first irradiation of three-dimensional samples.
The performance of laser based ion acceleration and the scaling of the laser energy to achieve increased ion energies strongly depend on the laser temporal contrast and its effect on the target plasma scale length. Plasma mirror setups have proven to be a valuable tool to significantly improve the temporal contrast by reducing pre-pulse intensity and steepening the rising edge of the main laser pulse. With such contrast enhancement techniques laser proton acceleration using ultra-thin foil targets as well as a renewable debris-free hydrogen jet (in collaboration with SLAC and European XFEL) target has been investigated in a series of experiments within the TNSA regime. An important implication of this is the demonstration of a credible path toward high repetition rate laser-based ion acceleration applications.

Demanding applications like radiation therapy of cancer are pushing the frontier of laser driven proton accelerators with controlled and well-defined proton beam properties. This talk will give an overview of recent achievements at the high-contrast high power laser source DRACO at HZDR. The laser system was recently upgraded by an additional Petawatt (PW) amplifier stage and new front end components finally providing high contrast pulses of >500 TW on target at 1 Hz pulse repetition rate. With the new PW beam line of Draco the feasibility of worldwide first controlled volumetric irradiation of a specifically developed tumor model, grown on the ears of nude mice with laser-accelerated protons are investigated. In order to efficiently capture and shape the divergent TNSA proton beam, a setup of two pulsed high-field solenoid magnets has been developed and applied. The talk will summarize results of the reliable generation of homogeneous depth dose distributions and first irradiation of three-dimensional samples.
The performance of laser based ion acceleration and the scaling of the laser energy to achieve increased ion energies strongly depend on the laser temporal contrast and its effect on the target plasma scale length. Plasma mirror setups have proven to be a valuable tool to significantly improve the temporal contrast by reducing pre-pulse intensity and steepening the rising edge of the main laser pulse. With such contrast enhancement techniques laser proton acceleration using ultra-thin foil targets as well as a renewable debris-free hydrogen jet (in collaboration with SLAC and European XFEL) target has been investigated in a series of experiments within the TNSA regime. An important implication of this is the demonstration of a credible path toward high repetition rate laser-based ion acceleration applications.

The development of high-intensity short-pulse lasers in the Petawatt regime offers the possibility to design new compact accelerator schemes by utilizing high-density targets for the generation of high energy ion beams. The optimization of the acceleration process demands comprehensive diagnostic of the plasma dynamics involved, for example via spatially and temporally resolved optical probing. Experimental results can then be compared to numerical particle-in-cell simulations, which is particularly sensible in the case of cryogenic hydrogen jet targets [1]. However, strong plasma self-emission and conversion of the plasma’s drive laser wavelength into its harmonics often masks the interaction region and interferes with the data analysis. Recently, the development of a stand-alone and synchronized probe laser system for off-harmonic probing at the DRACO laser operated at the Helmholtz-Zentrum Dresden–Rossendorf showed promising performance [2].
Here, we present an updated stand-alone probe laser system applying a compact CPA system based on a synchronized fs mode-locked oscillator operating at 1030 nm, far off the plasma’s drive laser wavelength of 800 nm. A chirped volume Bragg grating is used as a hybrid stretcher and compressor unit [3]. The system delivers 160 fs pulses with a maximum energy of 0.9 mJ. By deploying the probe laser pulses in laser-proton acceleration experiments with renewable cryogenic hydrogen jet targets, the plasma self-emission could be significantly suppressed while studying the temporal evolution of the expanding plasma jet. Hence, for varied drive laser contrast parameters, by the use of a plasma mirror, the on target contrast was measured and correlated to the temporal drive laser profile.

References

[1] L. Obst, et al. Efficient laser-driven proton acceleration from cylindrical and planar cryogenic hydrogen jets. Sci. Rep., 7:10248, 2017.
[2] T. Ziegler, et al. Optical probing of high intensity laser interaction with micron-sized
cryogenic hydrogen jets. Plasma Phys. Control. Fusion, 2018. doi:10.1088/1361-6587/
aabf4f.
[3] L. Loeser, et al. A compact and robust millijoule CPA laser system based on Yb:CaF₂ delivering 160fs pulses. under review.

Laser-driven ion acceleration promises to provide a compact solution for demanding applications like radio-biology experiments. For that, controlling particle beam parameters particularly in experiments with high energy Petawatt class ultra-short pulse systems with high repetition rate is a mandatory, yet challenging task. The performance of the plasma acceleration is strongly dependent on the complex laser target interaction which in turn is determined by the temporal laser intensity profile and spatio-temporal couplings on a large dynamic range. Plasma mirror setups have proven to significantly improve the temporal contrast by reducing pre-pulse intensity and steepening the rising edge of the main laser pulse, enabling the investigation of laser proton acceleration using ultra-thin and near critical density targets. Here we present benchmark experiments using the DRACO Petawatt laser at HZDR irradiating ultra-thin foil targets. A combination of particle and plasma diagnostics for ions and electrons as well as reflected and transmitted light revealed clear indications of acceleration in the relativistic transparency regime. The experiments were complemented by a suite of different laser pulse diagnostics, including self-referenced spectral interferometry with extended time excursion for single shot contrast analysis to characterize the laser pulse properties at the high power focus as realistic as possible.

Realising the circular economy (CE) is faced with some significant challenges. Process metallurgy and its infrastructure play key roles at the heart of making the CE work. Therefore, the enabling role of process metallurgy within the CE will be central to the discussion in this paper, touching among others on product and system design as well as the key metallurgical and other process fundamentals that need to be investigated and understood to make the CE a reality. The central role of materials and its processing will be discussed in an integrated circular cities perspective. A key focus will be a discussion on designing a resilient “Smart Materials Grid” using and innovating metallurgical process engineering tools, which will manage the flows through Sustainable Circular Cities. The discussion will be using copper as leitmotiv of the discussion i.e. from copper ore, to metal, to complex products, recycling, product design and simulation and its impact.

The interpretation of helium ion microscopy (HIM) images of crystalline metal clusters requires microscopic understanding of the effects of He ion irradiation on the system, including energy deposition and associated heating, as well as channeling patterns. While channeling in bulk metals has been studied at length, there is no quantitative data for small clusters. We carry out molecular dynamics simulations to investigate the behavior of gold nano-particles with diameters of 5–15 nm under 30 keV He ion irradiation. We show that impacts of the ions can give rise to substantial heating of the clusters through deposition of energy into electronic degrees of freedom, but it does not affect channeling, as clusters cool down between consecutive impact of the ions under typical imaging conditions. At the same time, high temperatures and small cluster sizes should give rise to fast annealing of defects so that the system remains crystalline. Our results show that ion-channeling occurs not only in the principal low-index, but also in the intermediate directions. The strengths of different channels are specified, and their correlations with sputtering-yield and damage production is discussed, along with size-dependence of these properties. The effects of planar defects, such as stacking faults on channeling were also investigated. Finally, we discuss the implications of our results for the analysis of HIM images of metal clusters.

Ion channeling is a well-known effect in ion irradiation processes, which is a result of ion moving between the rows of atoms. It drastically affects the ion distribution, ion energy-loss and consequently the damage production in the target. Therefore one could derive the ion-channeling pattern out of the energy-loss behavior of ion-target interaction.
Ion channeling effect is studied for a few pure element crystals and also for some compounds in a systematic way [1]. In this work, we focus on nano-structures which are of major importance, due to their high surface-to-volume ratio. Our results, for different gold cluster sizes, show that ion-channeling occurs not only in the principal low-index, but also in other directions in between. The strengths of different channels are specified, and their correlations with sputtering-yield and damage production is discussed.

Metals are eminently recyclable, and by recycling and refining complex materials, the interconnected metals sector is responding to the increasing scarcity of certain metals. In this way, the metals sector is delivering and recovering the technology and base metals for the Circular Economy (CE). Moreover, metals are at the heart of the energy infrastructures that now run Circular Cities, and they will play an even greater part in the future. Metals are key enablers in the CE, as it is capable of dissolving and carrying a multitude of technology elements. The recovery and recycling of several critical technology elements is based on refining them from molten metal through well-developed metallurgical processes in which these act as carrier metals. To put it simply, process metallurgy is fundamental if countries want to innovate leading positions in the global CE. This presentation is gleaning from a recent policy brief developed by industry and academia within the EU ETN SOCRATES.

We present Traveling-Wave Electron Acceleration (TWEAC), a novel compact electron accelerator scheme based on laser-plasma acceleration. While laser-plasma accelerators provide multi-GeV electron beams today, the acceleration to higher energies is limited. The sub-luminal group-velocity of plasma waves let electrons outrun the accelerating field.

In order to control the speed of the accelerating plasma cavity, TWEAC utilizes two pulse-front tilted laser pulses whose propagation directions enclose a configurable angle. The accelerating cavity is created along their overlap region in the plasma and can move at the vacuum speed of light. The oblique laser geometry enables to constantly cycle different laser beam sections through the interaction region, hence providing quasi-stationary conditions of the wakefield driver. Supported by 3D particle-in-cell simulations using PIConGPU, we show that TWEAC offers constant acceleration without a dephasing electron beam while avoiding usual laser pump depletion within the interaction region. This opens the way for electron energies beyond 10 GeV, possibly towards TeV class electron beams, without the need for multiple laser-accelerator stages. For lower GeV-scale electron energies, TWEAC at high plasma densities and 10TW-class laser systems could enable compact accelerators at kHz-repetition rates.

After analyzing stability of acceleration and possible limits of the scheme, we present energy scaling laws for both laser as well as electrons and detail experimental design considerations. By comparing the energy efficiency of various TWEAC designs to LWFA, we find using simulations that for low-angle TWEAC setups, it is possible to accelerate high-charge bunches with laser to electron beam energy efficiencies close to 50%, which exceeds energy efficiencies typically attained with LWFA.

The presentation gives an overview on the application of x-ray tomographic imaging for flow analysis in nuclear safety research. Its application is exemplified for two-phase flow imaging around a flow obstacle and gas holdup measurement in a heated rod bundle.

Laser-wakefield accelerators (LWFA) feature electron bunch durations on a fs-scale. Precise knowledge of the longitudinal profile of such ultra-short electron bunches is essential for the design of future compact X-ray light sources. Resolution limits, as well as the limited reproducibility of electron bunches, pose big challenges for LWFA beam diagnostics.

Spectral measurements of broadband transition radiation from LWFA electron bunches passing through a metal foil are especially promising for analyzing ultrashort longitudinal bunch characteristics ranging from of tens of fs down to sub-fs.

Our broadband, single-shot spectrometer combines the TR spectrum in UV/VIS (200-1000nm), NIR (0.9-1.7μm) and mid-IR (1.6-12μm). A complete characterization and calibration of the spectrometer has been done with regard to wavelengths, relative spectral sensitivities and absolute photometric sensitivity. Our spectrometer is able to characterize electron bunches with charges as low as 1 pC and resolve time-scales from 0.7 to 40 fs. In addition, complementary data on the transverse bunch profile is provided by simultaneously imaging the CTR in the far- and near-field.

We present recent experimental results of different LWFA injection mechanisms, such as self-truncated ionization-injection and self-injection. By analyzing the transition radiation spectra and reconstructing electron bunch profiles including error analysis, we determine electron bunch profiles and peak currents of the respective injection regimes. In addition to bunch durations and peak currents, we discuss sub-fs beam micro-structures and systematic experimental scans of the nitrogen doping concentration for ionization-induced injection.

The presentation gives an overview over the state of the art in imaging techniques for multiphase flows in chemical engineering.

Bubble column reactors are widespread in the chemical industry [1]. Hydrodynamics and mass transfer processes in bubble column reactors are difficult to predict, as they occur at different length and time scales. Thus, numerous parameters affect the performance of bubble column reactors in terms of yield and selectivity. These are the gas holdup, bubble size, bubble interfacial area, liquid-phase velocity, and mass transfer coefficients. In addition, the kinetics of the chemical reactions in a bubble column and the mixing of the reactants play a significant role and may even feedback on mass transfer and hydrodynamics. Within a German DFG Priority Programme we investigate the coupling between hydrodynamics, mass transfer and reaction in bubbly flows across the scales and with real chemical reaction systems [2]. Within this framework, our group studies the macroscale processes in laboratory bubble columns with selected experimental techniques. In our presentation, we will introduce two different ways for time-resolved local chemical species concentration measurement, i.e. the analysis of OH- consumption during chemisorption of CO2 in alkaline solution by electrochemical analysis using a wire-mesh sensor as well as chemical conversion of NO in Fe(II) (EDTA) solution with a fiber optical photospectrometry technique.