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35836 Publications

An atomic force microscope integrated with a helium ion microscope for correlative nanocharacterization

Andany, S. H.; Hlawacek, G.; Hummel, S.; Brillard, C.; Kangül, M.; Fantner, G. E.

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.

Keywords: AFM; HIM; Correlative Microscopy

Related publications

Permalink: https://www.hzdr.de/publications/Publ-30689
Publ.-Id: 30689


The Application Of Subspace Clustering Algorithms In Drill-Core Hyperspectral Domaining

Rafiezadeh Shahi, K.; Khodadadzadeh, M.; Tolosana Delgado, R.; Tusa, L.; Gloaguen, R.

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.

Keywords: Clustering algorithms; Hyperspectral imaging; Veins; Minerals; Signal processing algorithms; Clustering methods

  • Contribution to proceedings
    2019 10th Workshop on Hyperspectral Imaging and Signal Processing: Evolution in Remote Sensing (WHISPERS), 24.-26.09.2019, Amsterdam, Netherlands

Permalink: https://www.hzdr.de/publications/Publ-30688
Publ.-Id: 30688


Evaluation of performance improvements through application of anisotropic foam packings in rotating packed beds

Gładyszewski, K.; Groβ, K.; Bieberle, A.; Schubert, M.; Hild, M.; Górak, A.; Skiborowski, M.

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.

Keywords: Rotating packed beds; HIGEE; anisotropic; foam packings; mass transfer; hydrodynamic; computer tomography

Related publications

Permalink: https://www.hzdr.de/publications/Publ-30687
Publ.-Id: 30687


A subspace clustering algorithm with spatial regularization for mineral mapping.

Rafiezadeh Shahi, K.; Khodadadzadeh, M.; Tolosana Delgado, R.; Gloaguen, R.

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

Keywords: PIXELS; DRILL cores; REGULARIZATION (Mathematics); ORE deposits; SCANNING electron microscopy; MINERAL analysis

  • Open Access Logo Contribution to proceedings
    EGU General Assembly 2019, 07.-12.04.2019, Vienna, Austria
    Geophysical Research Abstracts

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Permalink: https://www.hzdr.de/publications/Publ-30686
Publ.-Id: 30686


Local vibrational modes of Si vacancy spin qubits in SiC

Shang, Z.; Hashemi, A.; Berencen, Y.; Komsa, H.-P.; Erhart, P.; Zhou, S.; Helm, M.; Krasheninnikov, A.; Astakhov, G.

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.

Keywords: Silicon carbide; Spin qubits; Defects; Vibrational modes; Quantum

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Permalink: https://www.hzdr.de/publications/Publ-30685
Publ.-Id: 30685


UAS aeromagnetic survey and hyperspectral data for mineral exploration

Madriz Diaz, Y. C.; Jackisch, R.; Zimmermann, R.; Gloaguen, R.

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.

Keywords: Airborne magnetics; magnetometer; hyperspectral; mineral exploration; UAS

  • Open Access Logo Invited lecture (Conferences)
    AGU-SEG Airborne Geophysics Workshop, 11.-13.06.2019, Davie, Florida, United States

Permalink: https://www.hzdr.de/publications/Publ-30684
Publ.-Id: 30684


Guided capped particles propulsion via hydrogen peroxide decomposition under magnetic field

Alsaadawi, Y.; Heigl, M.; Eichler-Volf, A.; Albrecht, M.; Gemming, S.; Erbe, A.

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.

  • Poster (Online presentation)
    Annual Meeting 2019 - SPP 1726 “Microswimmers – from single particle motion to collective behaviour”, 23.-24.05.2019, Bonn, Germany

Permalink: https://www.hzdr.de/publications/Publ-30683
Publ.-Id: 30683


Carboranyl Derivatives of Rofecoxib with Cytostatic Activity Against Human Melanoma and Colon Cancer Cells

Buzharevski, A.; Paskas, S.; Sárosi, M.-B.; Laube, M.; Lönnecke, P.; Neumann, W.; Murganić, B.; Mijatović, S.; Maksimović-Ivanić, D.; Pietzsch, J.; Hey-Hawkins, E.

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.

Keywords: cancer; rofecoxib; carborane; cytostatic drugs; NO-releasing drug

Permalink: https://www.hzdr.de/publications/Publ-30682
Publ.-Id: 30682


Fabrication of ellipsoidal microswimmers with controllable tip shape

Alsaadawi, Y.; Vazquez Luna, F.; Eichler-Volf, A.; Steinhart, M.; Erbe, A.

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

  • Poster
    Deutsche Physikalische Gesellschaft e. V., 01.04.2019, Regensburg, Germany

Permalink: https://www.hzdr.de/publications/Publ-30681
Publ.-Id: 30681


UAS aeromagnetic survey for mineral exploration using a fluxgate triaxial magnetometer.

Madriz Diaz, Y. C.; Jackisch, R.; Zimmermann, R.; Gloaguen, R.

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.

Keywords: Unmanned aircraft systems; Magnetic survey; Magnetometer; Airborne surveying

  • Invited lecture (Conferences)
    EGU General Assembly 2019, 08.-12.04.2019, Wien, Austria

Permalink: https://www.hzdr.de/publications/Publ-30680
Publ.-Id: 30680


The sigma-1 receptor: potential role in the modulation of cellular radiation sensitivity

Belter, B.; Deuther-Conrad, W.; Hofheinz, F.; Bachmann, M.; Brust, P.; Pietzsch, J.

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.

Keywords: Chaperone protein; clonogenic assay; endoplasmatic reticulum; intracellular transmembrane receptors; radioresistance; sigma-1 receptor ligands

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  • Secondary publication expected

Permalink: https://www.hzdr.de/publications/Publ-30679
Publ.-Id: 30679


CFD modelling of the combustion and heat transfer in the Top-Submerged-Lance smelter

Reuter, M.; Obiso, D.; Stelter, M.; Kriebitzsch, S.

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.

Keywords: TSL smelting; submerged combustion; CFD; pyrometallurgy

  • Poster
    TMS - The Mineral Society Annual Meeting, 10.-14.03.2019, San Antonio, Texas, Texas, USA
  • Contribution to proceedings
    10th European Metallurgical Conference, EMC 2019, 23.-26.06.2019, Düsseldorf, Germany
    Proceedings of the 10th European Metallurgical Conference, EMC 2019, Volume 2(2019), 631-638

Permalink: https://www.hzdr.de/publications/Publ-30678
Publ.-Id: 30678


Line-scan detection system to identify rare earth elements in rocks

Abend, T.; Sharma, S. K.; Fuchs, M.; Beyer, J.; Heitmann, J.; Gloaguen, R.

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.

Keywords: Photoluminescence (PL); rare earth elements (REE); line-scan; system integration

  • Lecture (Conference)
    IEEE Sensors 2019, 27.-30.10.2019, Montreal, Canada

Permalink: https://www.hzdr.de/publications/Publ-30677
Publ.-Id: 30677


Dynamic model of a TSL furnace, developed with SimuSageTMsoftware

van Schalkwyk, R. F.; Stelter, M.; Rezende, J.; Reuter, M.; To Baben, M.

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.

Keywords: Kinetics; Technology Elements; Lead; Pyrometallurgy; TSL; SimuSage

  • Contribution to proceedings
    European Metallurgical Conferrence EMC 2019, 23.-26.06.2019, Düsseldorf, Deutschland
    Dynamic model of a TSL furnace, developed with SimuSageTM software, Clausthal-Zellerfeld: GDMB Verlag GmbH, 78-3-940276-88-9, 697-710

Permalink: https://www.hzdr.de/publications/Publ-30676
Publ.-Id: 30676


Ice Complex formation on Bol’shoy Lyakhovsky Island (New Siberian Archipelago, East Siberian Arctic) since about 200 ka

Wetterich, S.; Rudaya, N.; Kuznetsov, V.; Maksimov, F.; Opel, T.; Meyer, H.; Guenther, F.; Bobrov, A.; Raschke, E.; Zimmermann, H.; Strauss, J.; Starikova, A.; Fuchs, M.; Schirrmeister, L.

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.

Keywords: Cryostratigraphy; ice wedges; stable isotopes; pollen; radioisotope disequilibria dating; Beringia

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  • Secondary publication expected

Permalink: https://www.hzdr.de/publications/Publ-30675
Publ.-Id: 30675


Geochemical Characterization of Tea Leaves (Camellia sinensis) and Soils for Provenance Studies based on Compositional Data Analysis

Pospiech, S.

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.

Keywords: tea; Camellia sinensis; compositional data; soil-plant interaction; plant analysis; plant ionom; provenance; Darjeeling

  • Doctoral thesis
    Georg-August-Universität Göttingen, 2019
    Mentor: Prof. H. Ruppert
    267 Seiten

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Permalink: https://www.hzdr.de/publications/Publ-30674
Publ.-Id: 30674


TWEAC - Energy-efficient Laser-plasma acceleration beyond the dephasing and depletion limits

Debus, A.; Pausch, R.; Hübl, A.; Steiniger, K.; Widera, R.; Cowan, T.; Schramm, U.; Bussmann, M.

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.

Keywords: Laser-produced plasmas; Plasma-based accelerators; Laser-wakefield acceleration; Traveling-wave electron acceleration; TWEAC

  • Poster
    5. Annual MT Meeting, 05.-7.3.2019, Jena, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30673
Publ.-Id: 30673


HESEB - Helmholtz-SESAME soft X-ray beamline

Attal, M.; Bahrdt, J.; Drube, W.; Eberhardt, W.; Esser, F. M.; Follath, R.; Froideval, A.; Genisel, M. F.; Huck, M.; Huttel, E.; Lehner, F.; Meseck, A.; Al Najdawi, M.; Natour, G.; Paolucci, G.; Scheer, M.; Schramm, B.; Schuppler, S.; Tiemann, C.; Weissig, A.

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.

  • Lecture (Conference)
    17th SESAME Users Meeting organized in combination with the ESUO (European synchrotron and FEL user organisation) regional meeting, 30.11.-01.12.2019, SESAME (Allan), Jordan

Permalink: https://www.hzdr.de/publications/Publ-30672
Publ.-Id: 30672


vdar - Discriminant Analysis Incorporating Individual Uncertainties

Pospiech, S.

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.

Keywords: R-Package; QDA; LDA; compositional data; weighted QDA; weighted LDA

Related publications

  • Software in external data repository
    Publication year 2020
    Programming language: R
    System requirements: R (>= 3.6.0)
    License: GPL-3
    Hosted on CRAN: Link to location

Permalink: https://www.hzdr.de/publications/Publ-30671
Publ.-Id: 30671


Scaling EUV and X-ray Thomson Sources to Optical Free-Electron Laser Operation with Traveling-Wave Thomson-Scattering

Debus, A.; Steiniger, K.; Albach, D.; Bussmann, M.; Löser, M.; Pausch, R.; Röser, F.; Schramm, U.; Siebold, M.

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.

Keywords: optical FEL; traveling-wave; Thomson scattering; pulse-front tilt; out-of-focus interaction; EUV; X-ray

  • Poster
    5. Annual MT Meeting, 05.-7.3.2019, Helmholtz Institut Jena, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30670
Publ.-Id: 30670


Influence of LWFA injection schemes on temporal pulse structure and peak current

Debus, A.; Zarini, O.; Laberge, M.; Couperus Cabadağ, J. P.; Köhler, A.; Kurz, T.; Schöbel, S.; Krämer, J.; Hannasch, A. J.; Zgadzaj, R.; Mewes, H.; Meißner, H.; Bussmann, M.; Downer, M.; Schramm, U.; Irman, A.

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.

Keywords: LWFA; Laser-wakefield acceleration; peak current; injection scheme; broadband spectrometer; single-shot bunch length measurement; coherent transition radiation; absolute calibration; electron bunch duration; longitudinal profile; absolute calibration; UV; VIS; NIR; MIR

  • Lecture (Conference)
    5. Annual MT Meeting, 05.-7.3.2019, Jena, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30669
Publ.-Id: 30669


Scalable laser-plasma acceleration using Traveling-Wave Electron Acceleration

Debus, A.; Pausch, R.; Hübl, A.; Steiniger, K.; Widera, R.; Cowan, T.; Schramm, U.; Bussmann, M.

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.

Keywords: Laser-produced plasmas; Plasma-based accelerators; Laser-wakefield acceleration; Traveling-wave electron acceleration; TWEAC

  • Lecture (Conference)
    4th European Advanced Accelerator Concepts Workshop (EAAC 2019), 15.-21.9.2019, La Biodola Bay, Isola d'Elba, Italy

Permalink: https://www.hzdr.de/publications/Publ-30668
Publ.-Id: 30668


Modeling the L|PWFA hybrid accelerator using PIConGPU

Debus, A.; Pausch, R.; Steiniger, K.; Hübl, A.; Widera, R.; Kurz, T.; Schöbel, S.; Chang, Y.-Y.; Couperus Cabadağ, J. P.; Köhler, A.; Heinemann, T.; Ding, H.; Döpp, A.; Giljohann, M.; Kononenko, O.; Gaurav, R.; Corde, S.; Hidding, B.; Karsch, S.; Martinez De La Ossa, A.; Irman, A.; Schramm, U.

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.

Keywords: LWFA; PWFA; laser wakefield acceleration; plasma wakefield acceleration; particle-in-cell simulations; PIC; hybrid L|PWFA; start-to-end simulation

  • Lecture (Conference)
    4th European Advanced Accelerator Concepts Workshop (EAAC 2019), 15.-21.9.2019, La Biodola Bay, Isola d'Elba, Italy

Permalink: https://www.hzdr.de/publications/Publ-30667
Publ.-Id: 30667


A spectral library for Smithsonian rare-earth element phosphate standards using laser-induced fluorescence

Fuchs, M.; Beyer, J.; Lorenz, S.; Sharma, S.; Renno, A.; Heitmann, J.; Gloaguen, R.

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.

Keywords: spectroscopy; laser-induced fluorescence; rare-earth elements

  • Open Access Logo Contribution to proceedings
    European Geoscience Union, 12.04.2019, Vienna, Austria

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-30666
Publ.-Id: 30666


Erfassung hydrodynamischer Kenngrößen in großen Prozessbehältern mittels instrumentierter Strömungsfolger

Hampel, U.

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.

Keywords: instrumented flow followers; autonomous sensors; process measurement; process engineering

  • Invited lecture (Conferences)
    Campus Mehrphasenreaktoren, 31.01.2020, Frankfurt am Main, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30665
Publ.-Id: 30665


Sensorik für die Digitalisierung chemischer Produktionsanlagen

Hampel, U.; Schütze, A.; Rädle, M.; Rück, T.; Krawczyk-Becker, M.; Musch, T.; Maiwald, M.; Fröhlich, H. J.; Zeck, S.

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.

Keywords: Messtechnik; Sensorik; Datenverarbeitung; chemische Industrie; Digitalisierung; Industrie 4.0

  • Other report
    Frankfurt am Main: DECHEMA e.V., 2020
    18 Seiten

Permalink: https://www.hzdr.de/publications/Publ-30664
Publ.-Id: 30664


Influence of carbon feeding on a pyrometallurgical tantalum and niobium recycling process and the formation of carbides

Reuter, M. A.; Taube, M. C.; Adam, C.; Adamczyk, B.; Beckmann, T.; Stelter, M.

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.

Keywords: Carbide formation; Carbon feeding; Pyrometallurgy; Reduction process; Tantalum

  • Contribution to proceedings
    Euopean Metallurgical Conference (EMC) 2019, 23.-26.06.2019, Düsseldorf, Deutschland
    Proceedings / EMC 2019, European Metallurgical Conference, Clausthal-Zellerfeld: GDMB Verlag GmbH, 978-3-940276-87-2, 371-386

Permalink: https://www.hzdr.de/publications/Publ-30663
Publ.-Id: 30663


Metallurgy: key enabler of the Circular Economy HSC Sim as a tool for the analysis of large CE SYSTEMS

Reuter, M. A.

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.

Keywords: Circular Economy; resource efficiency; HSC

  • Lecture (others)
    Outotec celebrates 70 years of technology innovation at Pori ORC, 15.-16.10.2019, Pori, Finnland

Permalink: https://www.hzdr.de/publications/Publ-30662
Publ.-Id: 30662


Challenges of the circular economy - A metallurgical perspective

Reuter, M. A.

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.

Keywords: circular economy; process metallurgy; thermoeconomics; exergy; design for recycling

  • Lecture (others)
    10. Scientific Exchange Day 2019, 07.02.2019, Linz, Österreich

Permalink: https://www.hzdr.de/publications/Publ-30661
Publ.-Id: 30661


Metallurgical Recycling infrastructure of THE circular economy (CE)

Reuter, M. A.

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

Keywords: Circular Economy; HSC; Copper; energy & resource efficiency

  • Lecture (others)
    Atlantic Copper Meeting, 13.12.2019, Madrid, Spanien

Permalink: https://www.hzdr.de/publications/Publ-30660
Publ.-Id: 30660


Steigender Energieaufwand bei der Gewinnung von Metallen – Möglichkeiten und Grenzen des Metallrecyclings

Reuter, M. A.

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.

Keywords: fossiles Erdöl; Metalle; Elektroenergie; Metalle; Kupfer; Seltenerdmetalle

  • Invited lecture (Conferences)
    Kobalt, Kupfer, Lithium & Co.: Phase-Out von Erdöl und Phase-In von Metallen, 21.-22.11.2019, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30659
Publ.-Id: 30659


Combined utilization of strategic minerals and construction material from tailings – chances and risks from technological, environmental and economic viewpoint

Dirlich, S.; Łuszak, R.

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.

Keywords: tailings material; metal recovery; construction material; combined utilization; hydrometallurgy; bioleaching

  • Lecture (others)
    STAIR-II Final Conference, 25.-26.09.2019, Warsawa, Polska

Permalink: https://www.hzdr.de/publications/Publ-30658
Publ.-Id: 30658


Pilot Plant for Metal Recovery from Flotation Tailings

Aubel, T.; Thürigen, F.; Kermer, R.; Fischer, H.; Janneck, E.; Dirlich, S.; Chmielarz, A.; Mayer, R.

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.

Keywords: tailings; tailings material; metal recovery; pilot plant; environmental protection

  • Lecture (Conference)
    IMWA2019: Mine Water: Technological and Ecological Challenges, 15.-19.07.2019, Perm, Russland

Permalink: https://www.hzdr.de/publications/Publ-30657
Publ.-Id: 30657


Main technology trends in processing – Data integration of LCA, materials modelling, process flowsheets

Reuter, M. A.

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

Keywords: Circular Economy; Car recycling; resource systems

  • Invited lecture (Conferences)
    Innovation, new technology trends and Skills for Raw Materials“New technology trends in exploration, mining and processing, Skills for Raw Materials, Horizon 2020 Raw Materials Information and Brokerage Event”, 18.-22.11.2019, Brüssel, Belgien

Permalink: https://www.hzdr.de/publications/Publ-30656
Publ.-Id: 30656


Laser-driven strong shocks with infrared lasers at intensity of 1016 W/cm2

Antonelli, L.; Trela, J.; Barbato, F.; Boutoux, G.; Nicolaï, P.; Batani, D.; Tikhonchuk, V.; Mancelli, D.; Tentori, A.; Atzeni, S.; Schiavi, A.; Baffigi, F.; Cristoforetti, G.; Viciani, S.; Gizzi, L. A.; Smid, M.; Renner, O.; Dostal, J.; Dudzak, R.; Juha, L.; Krus, M.

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.

Permalink: https://www.hzdr.de/publications/Publ-30655
Publ.-Id: 30655


Smart Kd-concept as efficient approach to improve geochemistry in reactive transport modelling

Stockmann, M.; Noseck, U.; Britz, S.; Flügge, J.; Becker, D.-A.; Brendler, V.

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.

  • Lecture (others)
    International Workshop on "How to integrate geochemistry at affordable costs into reactive transport for large-scale systems", 05.-07.02.2020, Dresden, Germany

Permalink: https://www.hzdr.de/publications/Publ-30654
Publ.-Id: 30654


Dose controlled irradiation experiments with laser-accelerated protons at Draco Petawatt

Brack, F.-E.; Kroll, F.; Metzkes-Ng, J.; Obst-Hübl, L.; Bernert, C.; Kraft, S.; Schlenvoigt, H.-P.; Gaus, L.; Beyreuther, E.; Karsch, L.; Pawelke, J.; Zeil, K.; Schramm, U.

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.

  • Lecture (Conference)
    European Advanced Accelerator Concepts Workshop (EAAC), 15.-21.09.2019, Elba, Italien

Permalink: https://www.hzdr.de/publications/Publ-30652
Publ.-Id: 30652


Metallurgy as the key enabler in Circular Economy, and bottlenecks by REACH and other policies on metal banning

Reuter, M. A.

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?

Keywords: resource efficiency; Circular Economy; metallurgy; Socrates; recycling

  • Invited lecture (Conferences)
    CICERONE - Funding the Circular Economy, 19.-20.11.2019, Berlin, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30651
Publ.-Id: 30651


Spin dynamics in strongly-correlated spin systems: physics and methodology

Zvyagin, S.

für diesen Vortrag hat keine inhaltliche Kurzfassung vorgelegen

  • Invited lecture (Conferences)
    Heinz Maier-Leibnitz Zentrum User Meeting, 10.-11.12.2019, Garching, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30650
Publ.-Id: 30650


Si nanopillar deformation by heavy polyatomic ion impacts

Bischoff, L.; Pilz, W.; Engelmann, H.-J.; Xu, X.; Möller, W.; Heinig, K.-H.; Ghaderzadeh, S.; Hlawacek, G.; Gharbi, A.; Tiron, R.

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

Keywords: Si nanopillars; Single Electron Transistors; FIB; Liquid Metal Alloy Ion Source [

  • Lecture (Conference)
    DPG conference, 15.-20.03.2020, Dresden, Germany

Permalink: https://www.hzdr.de/publications/Publ-30649
Publ.-Id: 30649


The European Joint Research Project UHDpulse - Metrology for advanced radiotherapy using particle beams with ultra-high pulse dose rates

Schüller, A.; Heinrich, S.; Fouillade, C.; Subiel, A.; Ludovic, D. M.; Romano, F.; Solc, J.; Bailat, C.; Pawelke, J.; Borghesi, M.; Kapsch, R.-P.; Gomez, F.; Olsovcova, V.; Kottler, C.; Fleta, C.; Jakubek, J.; Poppinga, D.; Caresana, M.; Ambrozova, I.; Knyziak, A.; Vozenin, M.-C.

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.

Keywords: Dosimetry; FLASH beams; Absorbed dose; Traceability; High dose rates; European metrology project

Permalink: https://www.hzdr.de/publications/Publ-30648
Publ.-Id: 30648


Metall-Kreislaufwirtschaft - Potentiale und Grenzen // Smartphone: IconographiC example for digital transformation

Reuter, M. A.

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

Keywords: Circular Economy; SOCRATES; Recycling; footprint of minor metals; car recycling; emobility

  • Invited lecture (Conferences)
    Metalle – Voraussetzung der digitalen Transformation, 08.-09.11.2019, Tutzingen, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30645
Publ.-Id: 30645


Smelters and refineries strategies to mitigate impact of minor metal increase in feed

Reuter, M. A.

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?

Keywords: circular society; emobility; recycling; circular economy; process metallurgy

  • Invited lecture (Conferences)
    Third Minor Metal Symposium: Multi Metal Management and Sustainable Processing of Complex Sulfide Materials, 19.-21.10.2019, Lissabon, Portugal

Permalink: https://www.hzdr.de/publications/Publ-30644
Publ.-Id: 30644


The eco-footprint of raw materials. Current limits.

Reuter, M. A.

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?

Keywords: ecological footprint; circular SOCIETY; emobility; resource efficiency; Circular Economy

  • Invited lecture (Conferences)
    4th Expert Forum on Sustainable Materials for Future Mobility/Electrification and Lightweight Design, 07.-09.10.2019, Nizza, Frankreich

Permalink: https://www.hzdr.de/publications/Publ-30643
Publ.-Id: 30643


Testing cave ice deposits as archives of past atmospheric ¹⁰Be deposition

Kern, Z.; Ruszkiczay-Rüdiger, Z.; Perșoiu, A.; Merchel, S.; Gärtner, A.; Rugel, G.; Lachner, J.; Steier, P.

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/gice to (4.17±0.16)×10⁴ at/gice 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/gice, 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.

Keywords: AMS; ice; cave; dating; cosmogenic

  • Lecture (Conference)
    12th Scientific Conference - Research, protection and utilization of caves, 06.-10.09.2021, Liptovský Mikuláš, Slovakia
  • Aragonit Journal 25(2020)1, 45-47

Permalink: https://www.hzdr.de/publications/Publ-30642
Publ.-Id: 30642


Boron Liquid Metal Alloy Ion Sources for Special FIB Applications

Bischoff, L.; Klingner, N.; Mazarov, P.; Pilz, W.; Meyer, F.

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.

Keywords: Boron Liquid Metal Alloy Ion Source; Focused Ion Beam

  • Open Access Logo Journal of Vacuum Science & Technology B 38(2020)4, 042801-1-042801-5
    DOI: 10.1116/6.0000073

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Permalink: https://www.hzdr.de/publications/Publ-30640
Publ.-Id: 30640


Numerical optimization of a finned tube bundle heat exchanger arrangement for passive spent fuel pool cooling to ambient air

Unger, S.; Krepper, E.; Beyer, M.; Hampel, U.

This is the data set for the corresponding journal publication " Numerical optimization of a finned tube bundle heat exchanger arrangement for passive spent fuel pool cooling to ambient air".

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2020-01-24
    DOI: 10.14278/rodare.235
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-30638
Publ.-Id: 30638


Direct detection of the pulp-froth interface using the ultrasound transit time technique

Richter, T.; Heitkam, S.; Eckert, K.

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%.

  • Poster
    Flotation 2019, 11.-14.11.2019, Cape Town, South Africa

Permalink: https://www.hzdr.de/publications/Publ-30637
Publ.-Id: 30637


Novel Methods for Controlled Self-Catalyzed Growth of GaAs Nanowires and GaAs/AlxGa1-xAs Axial Nanowire Heterostructures on Si Substrates by Molecular Beam Epitaxy

Tauchnitz, T.

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-SiOx/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 SiOx, 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/AlxGa1-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/AlxGa1-xAs axial quantum well nanowires with abrupt interfaces and tunable thickness and Al-content of the AlxGa1-xAs sections. The GaAs/AlxGa1-xAs axial nanowire heterostructures are interesting for applications as single photon emitters with tunable emission wavelength, when they are overgrown with thick lattice-mismatched InxAl1-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.

  • Open Access Logo Wissenschaftlich-Technische Berichte / Helmholtz-Zentrum Dresden-Rossendorf; HZDR-108 2020
    ISSN: 2191-8708, eISSN: 2191-8716

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Permalink: https://www.hzdr.de/publications/Publ-30636
Publ.-Id: 30636


Laser ion acceleration experiments using the Draco PW facility at HZDR

Zeil, K.

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.

  • Lecture (others)
    Plasmaphysikseminar der GSI, 30.04.2019, Darmstadt, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30635
Publ.-Id: 30635


Laser ion acceleration using the Draco Petawatt facility at HZDR

Zeil, K.

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.

  • Lecture (others)
    Seminarvortrag bei CALA, LMU München, 13.12.2019, München, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30634
Publ.-Id: 30634


Off-harmonic optical probe diagnostic for high intensity laser interaction with hydrogen targets

Zeil, K.; Bernert, C.; Kraft, S.; Loeser, M.; Metzkes-Ng, J.; Obst-Huebl, L.; Rehwald, M.; Schlenvoigt, H.-P.; Siebold, M.; Ziegler, T.; Schramm, U.

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.

  • Lecture (Conference)
    Laser Plasma Accelerator Workshop, 09.05.2019, Split, Kroatien

Permalink: https://www.hzdr.de/publications/Publ-30633
Publ.-Id: 30633


Ion acceleration from ultra-thin foil targets using a PW-class laser with optimized temporal pulse profile

Zeil, K.; Bernert, C.; Bock, S.; Brack, F.; Kraft, S.; Kroll, F.; Metzkes-Ng, J.; Obst-Huebl, L.; Pueschel, T.; Rehwald, M.; Schlenvoigt, H.-P.; Ziegler, T.; Schramm, U.

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.

  • Lecture (Conference)
    European Advanced Accelerator Conference, 17.09.2019, Elba, Italien

Permalink: https://www.hzdr.de/publications/Publ-30632
Publ.-Id: 30632


SPCI-Reconstruction

Kornek, D.; Berthold, J.; Kögler, T.

Single plane Compton imaging (SPCI) is a novel approach to medical imaging of gamma radiation [1]. The possible range of applications includes nuclear imaging and range verification in proton therapy. For the purpose of image reconstruction, a software tool written in ROOT [2] and named SPCI-Reconstruction [3] has been developed. The implementation features the well-established MLEM algorithm for binned data [4] as well as a Monte-Carlo based algorithm called Origin Ensemble [5]. Given a precalculated system matrix and a file containing the measurements, the emission densities of the gamma radiation source can be backprojected into a voxel-based image space.

[1] Pausch G et al. A novel scheme of compton imaging for nuclear medicine. 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop (NSS/MIC/RTSD).

[2] CERN. ROOT – Data Analysis Framework. Release 6.12/04 - 2017-12-13. https://root.cern.ch/content/release-61204.

[3] Kornek D. Anwendung von Maximum-Likelihood Expectation-Maximization und Origin Ensemble zur Rekonstruktion von Aktivitätsverteilungen beim Single Plane Compton Imaging (SPCI). Master's thesis. TU Dresden. 2019.

[4] Shepp LA, Vardi Y. Maximum likelihood reconstruction for emission tomography. IEEE Trans Med Imaging. 1982; 1(2):113-22.

[5] Sitek A. Representation of photon limited data in emission tomography using origin ensembles. Phys Med Biol. 2008 June; 53(12):3201-3216.

Keywords: single plane compton imaging; compton camera; image reconstruction; maximum-likelihood expectation-maximization; origin ensemble; nuclear medicine; range verification in particle therapy

  • Software in the HZDR data repository RODARE
    Publication date: 2020-01-17
    DOI: 10.14278/rodare.191
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-30631
Publ.-Id: 30631


Process Metallurgy in Circular Economy System Design: Challenges & Solutions

Reuter, M. A.; Bartie, N.

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.

Keywords: circular economy; Process metallurgy; “Smart Materials Grid”; Sustainable Circular Cities

  • Invited lecture (Conferences)
    COM 2019 Hosting Copper 2019, 18.-21.08.2019, Vancouver, Canada

Permalink: https://www.hzdr.de/publications/Publ-30630
Publ.-Id: 30630


Effects of He ion irradiation on gold nanoclusters: a Molecular Dynamics study

Ghaderzadeh, S.; Ghorbani Asl, M.; Kretschmer, S.; Hlawacek, G.; Krasheninnikov, A.

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.

Keywords: Helium Ion Microscope; Channeling effect; Nano particles; Ion irradiation

  • Lecture (Conference)
    AVS 66th International Symposium & Exhibition, 20.-25.10.2019, Columbus, United States of America

Permalink: https://www.hzdr.de/publications/Publ-30629
Publ.-Id: 30629


Effects of gold nanoclusters under He ion irradiation: a molecular dynamics study

Ghaderzadeh, S.; Ghorbani Asl, M.; Hlawacek, G.; Krasheninnikov, A.

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.

Keywords: Helium Ion Microscope; Nano particles; Channeling effect; Ion irradiation

  • Poster
    Towards Reality in Nanoscale Materials X, 12.-14.02.2019, Levi, Finland

Permalink: https://www.hzdr.de/publications/Publ-30627
Publ.-Id: 30627


Process Metallurgy is Fundamental to the Circular Economy

Reuter, M. A.

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.

Keywords: Circular Economy; Circular Cities; process metallurgy; SOCRATES

  • Invited lecture (Conferences)
    Waste innovation for a circular economy / Cutting Edge Science and Engineering Symposium, 27.-29.05.2019, Clayton, Australien

Permalink: https://www.hzdr.de/publications/Publ-30626
Publ.-Id: 30626


Traveling-Wave Electron Acceleration - Energy-efficient Laser-plasma acceleration beyond the dephasing and depletion limits

Debus, A.; Pausch, R.; Hübl, A.; Steiniger, K.; Widera, R.; Cowan, T.; Schramm, U.; Bussmann, M.

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.

Keywords: Laser-produced plasmas; Plasma-based accelerators; Laser-wakefield acceleration; Traveling-wave electron acceleration; TWEAC

  • Lecture (Conference)
    Laser-Plasma Accelerator Workshop 2019, 05.-10.5.2019, Split, Kroatien

Permalink: https://www.hzdr.de/publications/Publ-30624
Publ.-Id: 30624


Tomographic imaging of two-phase flow

Hampel, U.

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.

Keywords: tomographic imaging; X-ray tomography; two-phase flow; rod bundle

  • Lecture (Conference)
    3rd Sino-German Symposium on Fundamentals of Advanced Nuclear Safety Technology SG-FANS-3, 25.-27.09.2019, Xi'an, China

Permalink: https://www.hzdr.de/publications/Publ-30623
Publ.-Id: 30623


Determining impact of LWFA injection schemes on electron bunch profiles and peak currents based on broadband, spectral CTR diagnostics at single shot

Debus, A.; Zarini, O.; Laberge, M.; Couperus Cabadağ, J. P.; Köhler, A.; Kurz, T.; Schöbel, S.; Kraemer, J.; Hannasch, A. J.; Zgadzaj, R.; Mewes, H.; Meißner, H.; Bussmann, M.; Downer, M.; Schramm, U.; Irman, A.

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.

Keywords: LWFA; Laser-wakefield acceleration; peak current; injection scheme; broadband spectrometer; single-shot bunch length measurement; coherent transition radiation; absolute calibration; electron bunch duration; longitudinal profile; absolute calibration; UV; VIS; NIR; MIR

  • Lecture (Conference)
    Laser-Plasma Accelerator Workshop 2019, 05.-10.5.2019, Split, Kroatien

Permalink: https://www.hzdr.de/publications/Publ-30622
Publ.-Id: 30622


Imaging techniques for multiphase flows - Needs and recent developments

Hampel, U.

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

Keywords: imaging techniques; multiphase flow

  • Invited lecture (Conferences)
    Bernal Fluids Day, 26.06.2019, Limerick, Irland

Permalink: https://www.hzdr.de/publications/Publ-30621
Publ.-Id: 30621


Experimental analysis of reactive bubbly flows

Kipping, R.; Kryk, H.; Hampel, U.

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.

Keywords: bubble columns; mass transfer; chemical species concentration measurement

  • Lecture (Conference)
    Gas-Liquid and Gas-Liquid-Solid Reactor Engineering (GLS-14), 30.05.-03.06.2019, Guilin, China

Permalink: https://www.hzdr.de/publications/Publ-30620
Publ.-Id: 30620


Vacancy-Hydrogen Dynamics in Samples during Low Temperature Baking

Wenskat, M.; Bate, C.; Cizek, J.; Liedke, M. O.; Butterling, M.; Hirschmann, E.; Wagner, A.; Reschke, D.; Weise, H.

The recent discovery of a modified low temperature baking process established an increased accelerating gradient of TESLA shaped cavities through reduction of surface losses.
A possible explanation for the performance gain is the suppression of lossy nanohydrides via defect trapping, with vacancy-hydrogen (v+nH) complexes forming at the lower temperatures. Utilizing Doppler broadening Positron Annihilation Spectroscopy, Positron Annihilation Lifetime Spectroscopy and Nuclear Reaction Analysis, samples made from European XFEL niobium sheets and cavity cut-outs were investigated. The evolution of vacancies, hydrogen and their interaction at different temperature levels have been studied during in-situ and ex-situ annealing and in-situ cooldowns.
Measurements of niobium samples and a correlation between RF, material properties, and v+nH distribution in cavity cut-outs have been carried out.

Keywords: PAS; Nb; superconductivity; defects; hydrogen

Permalink: https://www.hzdr.de/publications/Publ-30619
Publ.-Id: 30619


Challenges in grinding of fine-grained, complex ores

Buchmann, M.; Schach, E.; Leißner, T.; Kern, M.; Mütze, T.; Peuker, U.

Automated liberation analysis can be used for the analysis of grinding of skarn ores. For the case study a complex, fine grained cassiterite bearing skarn ore serves as feed material for grinding tests in a stirred media mill. The visualization of grinding is applied via binning of particle images from Mineral Liberation Analyzer (MLA) into characteristic property classes. Various grinding effects and challenges in interpretation are discussed for the progress of grinding with the presented visualization method.

Keywords: process mineralogy; MLA; cassiterite; binning

  • Lecture (Conference)
    9th International Symposium „Fine Grinding and Dispersing“, 11.-12.10.2018, Braunschweig, Germany

Permalink: https://www.hzdr.de/publications/Publ-30618
Publ.-Id: 30618


Evaluation of separation and segregation in dynamic air classifiers

Buchmann, M.; Mütze, T.

Dynamic air classifiers separate particles in a gas flow due to their different trajectories. The characteristic property of separation is the settling velocity of the particles which is influenced by their size, shape, and density. The present contribution takes a close look at the separation behaviour of heterogeneous feeds, in which valuables and gangue minerals show significant differences in density. A new concept of multi-dimensional characterization of a separation process is presented and compared to the classical approach of the evaluation by partition curves (split factor, cut size, separation efficiency etc.) The new concept utilises the complex information from an automated mineral liberation analysis (MLA) and provides information of the enrichment and segregation of individual mineral phases in the products.

  • Open Access Logo Contribution to proceedings
    16th European Symposium on Comminution & Classification (ESCC 2019), 02.-04.09.2019, Leeds, United Kingdom
    DOI: 10.5518/100/17

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-30617
Publ.-Id: 30617


Accelerated magnetic re-ordering in Ne+ irradiated FeAl thin films

Liedke, M. O.; Ehrler, J.; Bali, R.; Butterling, M.; Hirschmann, E.; Wagner, A.; Cizek, J.

Thermally activated (re)ordering processes in ferromagnetic Fe60Al40 thin films during in-situ annealing have been investigated by magnetometry and positron annihilation spectroscopy supported with atomic superposition calculations. A ferromagnetic A2-disordered phase coexists with a paramagnetic B2-ordered phase in the as-grown sputter deposited films. Due to thermal treatment at elevated temperature of 773K the B2-phase can be fully established. However, employing Ne+ irradiation as a tool to generate a pure A2-phase and subsequent mild temperature annealing the activation temperature for (re)ordering can be decreased to only 400K. It will be shown that due to immobile large vacancy clusters, which are dominant in the as-grown films and possess a high thermal activation barrier the ordering is strongly hindered.
Ion irradiation breaks down these pinning defects strongly accelerating thermal diffusion and reordering. These results provide insights into thermal reordering processes in binary alloys, and the consequent effect on magnetic behavior.

Keywords: positron annihilation spectroscopy; FeAl; AIDA; MePS; PALS; PAS

  • Lecture (Conference)
    DPG-Frühjahrstagung — Regensburg, 31.03.2019, Regensburg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30616
Publ.-Id: 30616


Electrical field-controlled ON-OFF ferromagnetism in single metal oxide films

Liedke, M. O.; Butterling, M.; Quintana, A.; Menéndez, E.; Hirschmann, E.; Sireus, V.; Nogués, J.; Sort, J.; Wagner, A.; Elsherif, A. G. A.

With respect to applications, substituting electric currents, which are nowadays used to operate spintronic devices, with electric fields, would result in a reduction of both the energy consumption and cost [1]. Co3O4 is a candidate for a tunable, non-volatile energy-efficient functional material whose magnetic properties can be controlled by electric voltage. In our current investigations the as-grown Co3O4 films consist of a paramagnetic (PM) phase only, which is transformed to a ferromagnetic (FM) state by electrolyte-gated and defect-mediated O and Co transport. A negative voltage reduces Co3O4 to Co (FM: ON), resulting in a phase separated material with Co- and O-rich regions. Applying a positive bias, the process is reversed oxidizing Co back to Co3O4 (PM: OFF). We will show that atoms migration is driven by rather complex vacancy states and a clear increase of the grain boundaries volume after negative biasing assists to O transport. Moreover, concomitantly with the PM phase transition due to the positive biasing the structural defects picture reverses to a large extent as well, which manifests as reduction in volume of both vacancy clusters and grain boundaries. Doppler broadening and positron annihilation lifetime spectroscopy have been used as an in-situ probe of electric field driven ionic transport of Co and O via different type of defects in Co3O4 systems [2].
[1] Y. Shiota, et al. Nature Mater. 11, 39 (2012)
[2] A. Quintana, E. Menéndez, M. O. Liedke, M. Butterling, A. Wagner, et al. ACS Nano 12, 10291 (2018)

Keywords: positron; positron annihilation spectroscopy; AIDA; magnetism; voltage

  • Poster
    “From Matter to Materials and Life” (MML), 12.02.2019, Dresden, Deutschland
  • Invited lecture (Conferences)
    15th International Workshop on Slow Positron Beam Techniques & Applications (SLOPOS-15), 02.09.2019, Prague, Czech Republic
  • Lecture (Conference)
    The European Materials Research Society (E-MRS) Fall Meeting, 16.09.2019, Warsaw, Poland

Permalink: https://www.hzdr.de/publications/Publ-30615
Publ.-Id: 30615


Measurement systems for liquid metals

Wondrak, T.

This talk represents an introduction into measurement techniques for liquid metals including invasive probes, ultrasonic and inductive methods as well as x-ray radiography.

Keywords: liquid metal; measurement techniques

  • Invited lecture (Conferences)
    PAMIR summer school 2019, 02.-5.7.2019, Reims, France

Permalink: https://www.hzdr.de/publications/Publ-30614
Publ.-Id: 30614


Inductive measurement techniques for liquid metals

Wondrak, T.

This talk represents an introduction into inductive measurement techniques for liquid metals.

Keywords: liquid metals; inductive measurement techniques; flow measurement

  • Invited lecture (Conferences)
    MHD Modelling School 2019, 14.-18.10.2019, Riga, Latvia

Permalink: https://www.hzdr.de/publications/Publ-30613
Publ.-Id: 30613


Misunterstandings – how dies the mining industry present itself in Europe and how is it perceived by society?

Reuter, M. A.

Europe’s mining sector aligns itself with the sustainability agenda through concepts such as the circular economy, the coming energy and resource transition, a zero-waste economy, etc. Ironically, these concepts also cause misunderstandings within society, most notably that no more mining or smeltering will be needed. This can be seen in the current debate on the ban of lead, i.e. lead is a necessary carrier element for many CRMs and lead-metallurgy is fundamental for a true circular economy. Is education enough to overcome these misunderstandings or is something else needed?

Keywords: Mireu; research; Social License to Operate; SLO; sustainability; circular economy; lead

  • Invited lecture (Conferences)
    3rd SLO workshop: ensuring SLO is adaptive and resilient, 05.-06.06.2019, Brüssel, Belgien

Permalink: https://www.hzdr.de/publications/Publ-30612
Publ.-Id: 30612


Contribution to the structure of the periodic classification of metals - Metals enable Future® Metalle vernetzen Zukunft®

Reuter, M.

The importance of metals in society //
The fundamental role of metals (incl. lead) in a circular society//
Metallurgical infrastructure criticality in a circular society

Keywords: metals; circular society; circular economy

  • Invited lecture (Conferences)
    EMC 2019 – 10th European Metallurgical Conference, 23.-26.06.2019, Düsseldorf, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30610
Publ.-Id: 30610


Inductive and resistive methods for gas detection

Wondrak, T.; Gundrum, T.; Willers, B.

This talk gives an overview about resistive and inductive methods for bubble detection in liquid metals.

Keywords: liquid metal; bubble detection

  • Lecture (Conference)
    ESFR-SMART European Workshop on Instrumentation for the Safety of Liquid Metal Facilities, 10.-12.04.2019, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30609
Publ.-Id: 30609


Contactless inductive flow tomography

Wondrak, T.; Ratajczak, M.; Stefani, F.

This talk gives an overview of the contactless inductive flow tomography and recent developments at HZDR.

Keywords: contactless inductive flow tomography; inductive flow measurement; liquid metal

  • Lecture (Conference)
    ESFR-SMART European Workshop on Instrumentation for the Safety of Liquid Metal Facilities, 10.-12.04.2019, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30608
Publ.-Id: 30608


“UniCAR”-modified off-the-shelf NK-92 cells for targeting of GD2-expressing tumour cells

Mitwasi, N.; Feldmann, A.; Arndt, C.; Koristka, S.; Berndt, N.; Jureczek, J.; Loureiro, L.; Bergmann, R.; Máthé, D.; Hegedüs, N.; Kovács, T.; Zhang, C.; Oberoi, P.; Jäger, E.; Seliger, B.; Rössig, C.; Temme, A.; Eitler, J.; Tonn, T.; Schmitz, M.; Hassel, J.; Jäger, D.; Wels, W.; Bachmann, M.

Antigen-specific redirection of immune effector cells with chimeric antigen receptors (CARs) demonstrated high therapeutic potential for targeting cancers of different origins. Beside CAR-T cells, natural killer (NK) cells represent promising alternative effectors that can be combined with CAR technology. Unlike T cells, primary NK cells and the NK cell line NK-92 can be applied as allogeneic off-the-shelf products with a reduced risk of toxicities. We previously established a modular universal CAR (UniCAR) platform which consists of UniCAR-expressing immune cells that cannot recognize target antigens directly but are redirected by a tumour-specific target module (TM). The TM contains an antigen-binding moiety fused to a peptide epitope which is recognized by the UniCAR molecule, thereby allowing an on/off switch of CAR activity, and facilitating flexible targeting of various tumour antigens depending on the presence and specificity of the TM. Here, we provide proof of concept that it is feasible to generate a universal off-the-shelf cellular therapeutic based on UniCAR NK-92 cells targeted to tumours expressing the disialoganglioside GD2 by GD2-specific TMs that are either based on an antibody-derived single-chain fragment variable (scFv) or an IgG4 backbone. Redirected UniCAR NK-92 cells induced specific killing of GD2-expressing cells in vitro and in vivo, associated with enhanced production of interferon-γ. Analysis of radiolabelled proteins demonstrated that the IgG4-based format increased the in vivo half-life of the TM markedly in comparison to the scFv-based molecule. In summary, UniCAR NK-92 cells represent a universal off-the-shelf platform that is highly effective and flexible, allowing the use of different TM formats for specific tumour targeting.

Permalink: https://www.hzdr.de/publications/Publ-30607
Publ.-Id: 30607


Pulsed-Magnet Developments at the Dresden High Magnetic Field Laboratory

Zherlitsyn, S.

für diesen Vortrag hat keine inhaltliche Kurzfassung vorgelegen

  • Invited lecture (Conferences)
    MT 26 - International Conference on Magnet Technology, 22.-27.09.2019, Vancouver, Canada

Permalink: https://www.hzdr.de/publications/Publ-30606
Publ.-Id: 30606


Pressure-Tuning the Quantum Spin Hamiltonian of the Triangular Lattice Antiferromagnet Cs2CuCl4: High-Field ESR Studies

Zvyagin, S.

für diesen Vortrag hat keine inhaltliche Kurzfassung vorgelegen

  • Invited lecture (Conferences)
    Conference EPR-75 (Electron Paramagnetic Resonance (EPR)), 23.-27.09.2019, Kazan, Russia

Permalink: https://www.hzdr.de/publications/Publ-30604
Publ.-Id: 30604


Spin-Lattice Coupling in a Yafet-Kittel Ferrimagnetic Spinel

Miyata, A.

für diesen Vortrag hat keine inhaltliche Kurzfassung vorgelegen

  • Invited lecture (Conferences)
    14th Asia-Pacific Physics Conference (APPC), 17.-22.11.2019, Kuching, Malaysia

Permalink: https://www.hzdr.de/publications/Publ-30603
Publ.-Id: 30603


Materialien die sich Kälte merken

Gottschall, T.

für diesen Vortrag hat keine inhaltliche Kurzfassung vorgelegen

  • Invited lecture (Conferences)
    Verständliche Wissenschaft 2019, 14.02.2019, Geesthacht, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30602
Publ.-Id: 30602


Magnetocaloric materials for solid-state refrigeration

Gottschall, T.

für diesen Vortrag hat keine inhaltliche Kurzfassung vorgelegen

  • Invited lecture (Conferences)
    Institutsseminar Fraunhofer IWS, 02.09.2019, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30601
Publ.-Id: 30601


A short history about (nearly) everything concerning bio-research in Dresden

Schäfer, S.

  • Lecture (others)
    Vorlesung an der Universidad de Granada, 17.12.2019, Granada, Spain

Permalink: https://www.hzdr.de/publications/Publ-30600
Publ.-Id: 30600


Development of turbulent cellular structures in Rayleigh-Benard convection in a finite liquid metal layer

Tasaka, Y.; Akashi, M.; Yanagisawa, T.; Vogt, T.; Eckert, S.

Large-scale, coherent flow structures of Rayleigh-Bénard convection in a finite liquid metal layer were examined experimentally by means of ultrasonic Doppler velocimetry. The fluid layer with aspect ratio of five and L = 40 mm in height was filled with eutectic alloy of GaInSn (Prandtl number, Pr = 0.03), and multiple ultrasonic transducers for the velocimetry were mounted in the side wall of the vessel to capture three-dimensional structures of the convection.
Spatio-tempral velocity maps obtained at different Rayleigh numbers in the range, 7900 < Ra < 180000, elucidated emergences of wavy-roll-like coherent structures, where the roll axis is determined quasi-randomly. The roll structure takes transition with reducing the number of rolls from four to three as Ra increases via intermediate regime between the two conditions, four or three rolls. With further increase of Ra a cellular structure with characteristics of fully developed thermal turbulence occupies the entire fluid layer. We will discuss details on derivation of the power law and relation with turbulent superstructures that have recently been discussed.

Keywords: Rayleigh-Benard convection; liquid metal; velocity measurements; coherent structures

  • Lecture (Conference)
    17th European Turbulence Conference, 03.-06.09.2019, Torino, Italy

Permalink: https://www.hzdr.de/publications/Publ-30597
Publ.-Id: 30597


Liquid Metal Model Experiments for Continuous Casting of Steel

Schurmann, D.; Eckert, S.

Experimental investigations of the fluid flow in the continuous casting mold are performed at the Mini-LIMMCAST facility of HZDR, which is a liquid metal mockup operated with GaInSn at room temperature. Velocity measurements in the non-transparent liquid metal are performed by means of the ultrasound Doppler velocimetry (UDV), which enables the reconstruction of the complex flow pattern in the mold. The focus of our study is on the influence of different electromagnetic actuators like electromagnetic brakes (EMBr) or electromagnetic stirring (EMS) on the mold flow in slab and bloom geometries.

Keywords: experimental investigation; liquid metal model; continuous casting; electromagnetic brake; electromagnetic stirring

  • Lecture (others)
    CFD and Thermomechanics Days, 04.-06.02.2020, Online, Internet

Permalink: https://www.hzdr.de/publications/Publ-30596
Publ.-Id: 30596


Novel low resistivity glass: MRPC detectors for ultra high rate applications

Liu, Z.; Beyer, R.; Dreyer, J.; Fan, X.; Greifenhagen, R.; Kim, D.-W.; Kotte, R.; Laso García, A.; Naumann, L.; Römer, K.; Stach, D.; Uribe Estrada, C.; Williams, M. C. S.; Zichichi, A.

Multigap Resistive Plate Chambers (MRPCs) are often used as time-of-flight (TOF) detectors for high-energy physics and nuclear experiments thanks to their excellent time accuracy. For the Compressed Baryonic Matter (CBM) TOF system, MRPCs are required to work at particle fluxes on the order of 1-10 kHz/cm² for the outer region and 10-25 kHz/cm² for the central region. Better time resolution will allow particle identification with TOF techniques to be performed at higher momenta. From our previous studies, a time resolution of 25 ps has been obtained with a 20-gap MRPC of 140 µm gap size with enhanced rate capbability. By using a new type of commercially available thin low-resistivity glass, further improvement MRPC rate capability is possible. In order to study the rate capability of the 10-gap MRPC built with this new low-resistivity glass, we have performed tests using the continuous electron beam at ELBE. This 10-gap MRPC, with 160 µm gaps, reaches 97% efficiency at 19.2 kV and a time resolution of 36 ps at particle fluxes near 2 kHz/cm². At a flux of 100 kHz/cm², the efficiency is still above 95% and a time resolution of 50 ps is obtained, which would fulfil the requirement of CBM TOF system.

Keywords: Multigap resistive plate chamber; Low resistivity glass; Rate capability; Efficiency; Time resolution

Permalink: https://www.hzdr.de/publications/Publ-30595
Publ.-Id: 30595


Interprofessionelle Kooperation in klinischen Studien. Zunehmender Bedarf, Komplexität und Anregungen am Beispiel einer prospektiv-onkologischen Multicenter-Studie.

Zippel, C.; Giesel, F.; Kopka, K.

Um neue Erkenntnisse in für Patienten nützliche Behandlungsansätze überführen zu können, werden in der medizinischen (onkologischen) Translationsforschung zunehmend prospektive klinische Studien initiiert. Damit diese Studien möglichst effizient und effektiv durchgeführt werden können, bedarf es der engen Kooperation und Kommunikation von Experten aus verschiedenen Berufsgruppen. In diesem Aufsatz beleuchten wir am Beispiel der prospektiven onkologisch-klinischen DKTK-PSMA-Studie der Phasen-I/-II „68Ga-PSMA-11 in Hochrisiko-Prostatakrebs“, welche wesentlichen Professionen bei der Planung, Vorbereitung und Durchführung von (nuklearmedizinisch) klinischen Studien involviert sein können und welche essenziellen Aufgaben diese zur Verwirklichung der Studie leisten. Darauf aufbauend führen wir allgemeine organisatorische Maßnahmen an, durch welche die interprofessionelle Zusammenarbeit bei künftig weiteren (nicht nur onkologischen)
Studien gefördert werden kann.

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-30594
Publ.-Id: 30594


Challenges of the Circular Economy

Reuter, M. A.

A Circular Economy (CE) paradigm aims to maximize sustainability and resource efficiency by extending product life cycles and using wastes as resources. So, what is the brave step that will deliver the CE for modern services, complex products, and society in general? Questions we should, among others, ask and attempt to answer are (i) What are the challenges to achieve this move forward? (ii) What does the metallurgical infrastructure have to be that maximally recovers materials from increasingly complex products and services, while returning high quality materials back into the CE? (iii) What smart energy and water grid will maximize resource efficiency and minimize exergy destruction of an increasingly complex society and system? In order to answer these questions, the role of metallurgical processing systems, smart materials production, digital technology platforms, product design etc. will be discussed in the context of Sustainable Circular Cities. It will furthermore be shown how digitalized real-time simulation and control of material and metal flow and metallurgical processing systems i.e. the “Smart Materials Grid - SMG” will form the heart of the CE system. The SMG will integrate into the water, energy, transport, heavy industry, and other grid systems and will help drive the resource efficiency of the future “Sustainable Circular Cities.” This will help to enable “Smart Sustainable Living” by also helping to quantify and realize the United Nation’s Sustainability Development Goals.

Keywords: Circular Economy; sustainability; resource efficiency; CE

  • Invited lecture (Conferences)
    REWAS 2019 Plenary Session, 10.-14.03.2019, San Antonio, Texas, USA

Permalink: https://www.hzdr.de/publications/Publ-30593
Publ.-Id: 30593


Physikalische und chemische Heterogenität von Oberflächen partikulärer Systeme

Stefan, H.

In den Prozessen der mechanischen Verfahrenstechnik (Flockung, Flotation, usw.) werden häufig partikuläre Feststoffsysteme in flüssigen Medien verarbeitet. Dabei spielen die interpartikulären Wechselwirkungen der jeweiligen dispersen Systeme eine entscheidende Rolle für das Prozessziel. Die Oberflächen der Partikel unterliegen chemischer und physikalischer Heterogenität, was den Prozessablauf maßgeblich beeinflussen kann.
Die Masterarbeit beschäftigt sich mit der Charakterisierung dieser Heterogentität mittels verschiedener Messmethoden an einem Modellpartikelsystem bestehend aus Kalk-Natron-Glas-Kugeln und Glasfasern. Zum einen steht die Partikelform bzw. deren Rauigkeit im Vordergrund, wobei letztere durch Ätzung mittels Flusssäure durch unterschiedliche Beanspruchungszeiten geändert wird. Die Partikelform wird variiert, indem zum einen kugelförmige, gebrochen kugelförmige und faserförmige Glas-Partikel vermessen werden. Die beiden zentralen Versuchsmethoden sind dabei die Messung der Haftkräfte zwischen den kugelförmigen Partikeln mittels Colloidal-Probe-Rasterkraftmikroskopie und der Messung der Oberflächenenergieverteilung mittels der inversen Gaschromatographie. Zusätzlich werden die zu untersuchenden Partikelsysteme chemisch durch Veresterung modifieziert, um den Einfluss der Benetzung mit zu berücksichtigen. Schlussendlich sollen dadurch Einblicke für den Einfluss der Heterogentität auf den Erfolg der Flotation bzw. der (Hetero)-Koagolation erzielt werden.

  • Master thesis
    TUBAF, 2019
    Mentor: Johanna Sygusch, Paul Knüpfer

Permalink: https://www.hzdr.de/publications/Publ-30592
Publ.-Id: 30592


Sub-10 nm Radiolabeled Barium Sulfate Nanoparticles as Carriers for Theranostic Applications and Targeted Alpha Therapy

Reissig, F.; Zarschler, K.; Hübner, R.; Pietzsch, H.-J.; Kopka, K.; Mamat, C.

The treatment of patients suffering from cancer with α-particle-emitting therapeutics continues to receive increasing interest. The range of radiopharmaceutically relevant α-emitters is limited to only a few radionuclides (e.g. actinium-225 and bismuth-213) as stable chelators or carrier systems for safe transport of the radioactive cargo are often lacking. Encapsulation of α-emitters into solid inorganic systems can help to diversify the portfolio of candidate radionuclides, providing that these nanomaterials effectively retain both the parent and the recoil daughters. We therefore focus on the design of stable and defined nanocarrier-based systems for various radionuclides including the promising α-emitting radionuclide radium-224. Hence, we report on the synthesis of sub-10 nm alendronate-functionalized barium sulfate nanoparticles, into whose matrix different radiometals including zirconium-89, indium-111, barium-131, barium-133, lutetium-177 and radium-224 were stably incorporated with appropriate yields. Our delivery systems show stabilities of g.t. 90% up to seven days regarding the radiometal release from the BaSO4 matrix. Furthermore, radium-224-labeled particles possess stabilities of 80% regarding the decay chain product lead-212. In fact, the majority of nanoparticles withstand the α-recoil and keeps the daughter radionuclides trapped. Noteworthy, due to the accessibility of reactive alendronate amine groups on their surface, it is possible to further modify this functionalized inorganic system by common amine-coupling strategies as exemplified herein by conjugation of fluorescein isothiocyanate. The synthesized nanoparticles exhibit some degree of nonspecific protein binding upon exposure to human serum, offering the possibility to add beneficial properties of a protein corona to the intrinsic features of the nanosystem.

Keywords: radium; alpha therapy; nanoparticle; delivery system

Permalink: https://www.hzdr.de/publications/Publ-30591
Publ.-Id: 30591


New Strategies for Imaging of Brain Cancer with Radiopharmaceuticals

Brust, P.

Background:
Brain cancer is a challenge for the health care system because of major problems for treatment. Radical surgery is not possible. Radiation treatment is restricted by missing borderlines, and drug treatment is limited by the blood-brain barrier. Therefore, glioblastoma multiforme, the most aggressive type of primary brain tumors, has a median overall survival of only ~12 months. Although new molecular pathways are being constantly discovered, translation of basic science into clinical practice is rather slow. Major obstacles in the resistance to therapy are heterogeneity of brain tumors, multiple genetic alterations, and their diffuse, infiltrative behavior. Hence monitoring of pathways related to tumor etiology and growth is highly important.
Methodology:
Positron emission tomography (PET) offers the potential to identify key signaling and metabolic pathways in tumors and to discover drugs for targeted therapy. An important prerequisite for PET is the development of radiolabeled molecules (radiotracer) to investigate impaired brain functions in living human subjects. Fluorine-18 is currently the most favorable radionuclide that is routinely used for radiolabeling because of its half-life of 109.8 min. The presentation will focus on the development of fluorine-18 labelled radiotracers bridging from basic science to biomedical application and focusing on four targets of major importance for brain cancer.
Results and Discussion:
Cannabinoids are known to induce apoptosis of glioma cells and the extent of cannabinoid CB2 receptor expression is related to tumor malignancy. The challenge in radiotracer development is the high expression of CB1 receptors. Therefore our strategies will be presented to achieve highly selective PET radiotracers for CB2 receptors.
The immunosuppressive effects of adenosine and the adenosine-triggered activation of catabolic energy production account for pro-cancer roles of extracellular adenosine. Accordingly, plasma-membrane-bound adenosine receptors were identified as new targets in the immunotherapy of brain tumors. Currently, we have PET radiotracers for A2A and A2B receptors under development, which are regarded as potential tools for therapy monitoring.
Sigma receptors, previously regarded as opioid receptors, are comprised of the σ1 and σ2 subtypes and represent orphan receptors of different families. While the σ1 receptor is a molecular chaperone, which interacts with various ion channels and G-protein coupled receptors, the σ2 receptor (TMEM97) is an intracellular protein located at the endoplasmatic reticulum that binds numerous drugs. There is evidence that both subtypes are important for glioblastoma growth thus facilitating the ongoing development of selective PET radiotracers for both subtypes in our department.
Furthermore, as other cancers glioblastoma is characterized by metabolic reprogramming to preferentially undergo aerobic glycolysis. The elevated production of lactate is accompanied by the increased expression of monocarboxylate transporters (MCTs). Accordingly a therapeutic approach targeting MCTs is a promising strategy in brain cancer treatment. A PET radiotracer for peripheral MCT1/MCT4 imaging has already been developed by us and will be discussed concerning its suitability for glioblastoma imaging.
Conclusion:
Numerous attempts are ongoing for molecular characterization of brain cancer with PET radiopharmaceuticals. It is expected that they will support in the future patient stratification and hence individualized therapy.

  • Lecture (Conference)
    International Symposium on Trends in Radiopharmaceuticals - ISTR 2019, 28.10.-01.11.2019, Wien, Österreich

Permalink: https://www.hzdr.de/publications/Publ-30590
Publ.-Id: 30590


Metallurgy is fundamental to the Circular Economy

Reuter, M. A.

The importance of metals in society,
The fundamental role of metals (incl. lead) in a circular society,
Metallurgical infrastructure criticality in a circular society

Keywords: metals; circular society

Related publications

  • Invited lecture (Conferences)
    International Lead Association conference, 19.-21.06.2019, Madrid, Spanien

Permalink: https://www.hzdr.de/publications/Publ-30589
Publ.-Id: 30589


Disturbing-free determination of yeast concentration in DI water and in glucose using impedance biochips

Kiani, M.; Du, N.; Vogel, M.; Raff, J.; Hübner, U.; Skorupa, I.; Bürger, D.; Schulz, S. E.; Schmidt, O. G.; Blaschke, D.; Schmidt, H.

Deionized water and glucose with yeast (Saccharomyces cerevisiae) of optical density OD600 ranging from 4 to 16 has been put in the ring electrode region of impedance biochips and impedance has been measured in dependence on the added volume (20, 21, 22, 23, 24, 25 L). Modeled impedance of the biochip reveals a linear relationship between the impedance model parameters and yeast concentration. Presented biochips allow for continuous impedance measurements without interrupting the cultivation of the yeast. A multiparameter fit of the impedance model parameters allows to determine the concentration of yeast cy in the range from cy = 3.3x107 to cy = 17x107 cells/mL. This work shows that independent on the liquid, DI water or glucose, the change of the impedance model parameters with increasing added volume of the liquid is clearly distinguishable from the change of impedance model parameters with increasing concentration of added yeast in the ring electrode region of the impedance biochips.

Keywords: Biochips; impedance spectroscopy; yeast Saccharomyces cerevisiae; electrical equivalent circuit; biomaterial; biosensing

Permalink: https://www.hzdr.de/publications/Publ-30588
Publ.-Id: 30588


Lead Metallurgy is Fundamental to the Circular Economy Policy Brief SOCRATES EU MSCA-ETN

Reuter, M.; Malfliet, A.; Blanpain, B.

Metals are eminently recyclable, and by recycling and refining complex materials, the EU's interconnected metals sector is responding to the increasing scarcity of certain metals. In this way, we are delivering and recovering the technology and base metals for the EU's 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. One of these metals is lead. With respect to this familiar metal, industry is fully aware that in order to keep on using it, the associated risks need to be well managed at all times. Importantly, lead is a key enabler 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 lead through well-developed metallurgical processes in which the lead acts as a carrier metal. Limiting lead metallurgy would have a detrimental impact, not only on the lead industry itself, but on all the industries linked to it. It is therefore critical that we maintain and further develop the lead infrastructure and know-how in Europe. To put it simply, lead metallurgy is fundamental if the EU wants to retain its leading position in the global CE. Executive Summary the 5 lessons learned: • Lesson 1: Lead is frequently seen as a problematic metal that can be detrimental to human health; what is much less well known is its fundamental role in extrac-tive metallurgy and how this is closely associated with the Circular Economy. • Lesson 2: Molten lead has unique properties that means it can act as an efficient liquid carrier for critical raw materials such as In, Bi, Cd and Te. • Lesson 3: Restricting lead metallurgy in the EU would not only have a detrimental impact on the lead industry, but also on all the industries linked to it that work with elements like Ag, Cu, Sb, Sn, Te, and Zn. • Lesson 4: The focus must be on correctly and comprehensively minimising the risks of lead-containing materials for society and carefully managing them, rather than attempting to ban the use of lead. • Lesson 5: An environmentally friendly and energy-efficient lead infrastructure together with the associated research and know-how in Europe is absolutely vital if the continent is to maintain its global leadership in the Circular Economy.

Keywords: recyclable; recycling; EU's Circular Economy; CE; Circular Cities; lead; research

Related publications

  • Other report
    ---: ETN Socrates, 2019
  • Lecture (Conference)
    Fifth SOCRATES network-wide event, 19.-21.02.2019, Leicester, England

Permalink: https://www.hzdr.de/publications/Publ-30586
Publ.-Id: 30586


Process metallurgy and systems in circular city design – the challenges

Reuter, M. A.

Realising the circular economy is faced with some significant challenges. Process metallurgy and its infrastructure play key roles at the heart of making the circular economy work. The enabling role of process metallurgy within the circular economy and circular cities will be discussed, touching also on product and system design.

Keywords: circular economy; process metallurgy; product and system design

  • Invited lecture (Conferences)
    Connecting Innovation in the Raw Materials Sector / EIT Raw Materials summit 2019, 20.-22.05.2019, Berlin, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30585
Publ.-Id: 30585


PET-Radiopharmaka - höchste Ansprüche an die Herstellung von radioaktiven Arzneimitteln für Patienten

Knieß, T.

"Radiopharmaka sind Arzneimittel die Radionuklide enthalten, deren Strahlungsaktivität unter anderem auch häufig auch für die Diagnose von Krebserkrankungen genutzt wird. Dabei werden bildgebende Verfahren angewandt, wo die emittierte Strahlung von einer Gamma-Kamera oder einem Tomographen aufgezeichnet wird. Für die Herstellung der Radiopharmaka werden spezielle Kenntnisse, Verfahren und Ausrüstungen benötigt. Der Vortrag beschreibt die Herstellung solcher kurzlebigen radioaktiven Arzneimittel im Helmholtz-Zentrum Dresden-Rossendorf und skizziert deren Anwendung in der Nuklearmedizin."

  • Lecture (others)
    Akademische Woche 2020, 05.02.2020, Meißen, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30584
Publ.-Id: 30584


Stability criterion for the magnetic separation of rare-earth ions

Lei, Z.; Fritzsche, B.; Eckert, K.

The stability criterion for the magnetic separation of rare-earth ions is studied, taking dysprosium Dy(iii) ions as an example. Emphasis is placed on quantifying the factors that limit the desired high enrichment. During magnetic separation, a layer enriched in Dy(iii) ions is generated via the surface evaporation of an aqueous solution which is levitated by the Kelvin force. Later, mass transport triggers instability in the enriched layer. The onset time and position of the instability is studied using an interferometer. The onset time signals that an advective process which significantly accelerates the stratification of enrichment is taking place, although the initial phase is quasi-diffusion-like. The onset position of the flow agrees well with that predicted with a generalized Rayleigh number (Ra∗=0) criterion which includes the Kelvin force term acting antiparallel to gravity. Further three-dimensional analysis of the potential energy, combining magnetic and gravitational terms, shows an energy barrier that has to be overcome to initiate instability. The position of the energy barrier coincides well with the onset position of the instability.

Keywords: Evaporation; Flow instability; Instability control; Optical interferometry; Transport phenomena

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-30582
Publ.-Id: 30582


Spectral tomography for 3D mineral and chemical analysis

Da Assuncao Godinho, J. R.; Renno, A.; de Schryver, T.; Masschaele, B.

A new analytical tool for mineral analysis will be introduced: Laboratory-based Spectral 3D X-ray Computed Tomography (Sp-CT). Results from a spectral imaging detector, prototype installed inside a TESCAN CoreTOM micro-CT system, will be presented and discussed in the context of mineralogical and chemical analysis of geological materials. The technique will be demonstrated to allow:
a) 3D mineral classification from the transmitted energy spectrum characteristic of a mineral phase.
b) Quick bulk chemical quantification of heavy elements with K-edge > 20 keV at high concentrations that are difficult to analyse by other methods.
c) Reducing common CT artefacts such as scattering and beam hardening, as well as improved contrast by selectively choose the most convenient energy range.
The advantages of Sp-CT will open new possibilities in geometallurgy and minerals processing research to move from the predominant 2D based image characterization towards more representative 3D characterization. These are fundamental steps to enable automated and routine 3D characterization that ultimately has the potential to provide faster and lower cost analysis to, for example, the mining industry, as well as more comprehensive rock characterization technique for Earth sciences research.

Keywords: XRCT; spectral XRCT

  • Poster
    PRORA - 10. Fachtagung Prozessnahe Röntgenanalytik, 28.-29.11.2019, Berlin, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30581
Publ.-Id: 30581


Applications in the Resource Industry - Between Handheld Instruments and 4D Methods

Renno, A.; Da Assuncao Godinho, J. R.; Gutzmer, J.; Kelly, N.; Reuter, M.; Seidel, P.; Sittner, J.; Winardhi, C. W.

An exemplary overview of the use of X-ray-based analytical methods in the resource industry, underpinned by examples, gives a very heterogeneous picture. The use of these methods is considered in the exploration, mining, mechanical processing and metallurgical/chemical processing of primary and secondary mineral and metallic raw materials.
Although X-ray diffraction, fluorescence, absorption and luminescence as well as various tomographic methods cover a very broad spectrum of methods, in many cases their use is apparently rather arbitrary, regardless of the respective matrix, technology and location.
For example for offline characterisation of raw materials and intermediates, established and reliable methods as well as pure estimation methods are used. In inline analytics, ad-hoc analytical instruments are used in addition to metrologically well-proven measuring systems that are well integrated into the respective technological processes. The enforcement of state standards with regard to environmental protection and resource use leads to a significant increase in the use of analytical technology and increased requirements for the certification of procedures.
A conspicuous feature is the constantly growing use of mobile "handheld devices", which are often used at decisive points to control the flow of materials. Very often, it can be observed that these devices, which in principle are very powerful, work under their respective capabilities or lead to significantly wrong results due to insufficiently thought-out and implemented measuring methods.
Almost all inline analytical methods used for sorting or process monitoring have the characteristic that they only lead to binary decisions. A comprehensive characterization of the material flow, which would lead both to flexible adaptation of the technologies used subsequently and to a significantly more differentiated splitting of the material flow, is a consequence of the ever more complex properties of the primary and secondary raw materials. This is the result of the change to economic forms with significantly stronger elements of a circular economy.
On the basis of current research at the HIF, it is presented how such a multi-effective measuring system could be designed. Furthermore, the advantages of the use of 3D methods in the characterization of primary and secondary raw materials as well as in the description of technological processes will be demonstrated. Both spectral XRCT (X-Ray Computed Tomography) and dynamic time-resolved XRCT methods are used.

Keywords: Resource Industry; Process Analysis; X-Ray Methods

  • Invited lecture (Conferences)
    PRORA - 10. Fachtagung Prozessnahe Röntgenanalytik, 28.-29.11.2019, Berlin, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30580
Publ.-Id: 30580


Halogen analysis of sulphide minerals at the ultratrace level – first applications of the Dresden Super-SIMS

Renno, A.; Rugel, G.; Wiedenbeck, M.; Ziegenrücker, R.

The integration of an ion source having very high spatial resolution with a tandem accelerator is a long-standing concept for improving analytical selectivity and sensitivity by orders of magnitude [1]. Translating this design concept into reality has its challenges [e.g. 2,3], meaning this approach has seldom been employed for mineralogical and geochemical research [e.g. 4].
Supporting a strong focus on natural, metallic and mineral resources, the Helmholtz Institute Freiberg for Resource Technology installed a so-called Super-SIMS at the Ion Beam Center at HZDR in Dresden-Rossendorf; this highly novel tool is devoted to the characterization of minerals and ores. The secondary ion beam from a CAMECA IMS 7f-auto is injected into the 6MV Dresden Accelerator Mass Spectrometry [5] facility, which effectively eliminates all molecular species from the ion beam.
We will present the current status of this initiative and will report our first results from halogen determinations (F, Cl, Br, I) in both sphalerite and galena. These data demonstrate a systematic and significant change in the counting rates of all halogens in mineralogically distinct areas of both minerals. Furthermore, we will describe our concepts for the quantification of these data at ultratrace levels.

[1] Matteson (2008) Mass Spec Rev 27, 470-484. [2] Ender et al. (1997) NIMB 123, 575-578. [3] Fahey et al. (2016) Anal Chem 88, 7145-7153. [4] Sie et al. (2000) NIMB 172, 228-234. [5] Rugel et al. (2016) NIMB 370, 94-100.

Keywords: SIMS; Super-SIMS; Halogen; Sphalerite; Galena

  • Lecture (Conference)
    GEOMÜNSTER 2019, 22.-25.09.2019, Münster, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-30579
Publ.-Id: 30579


Halogen analysis at the ultratrace level – first applications of the Dresden Super-SIMS

Renno, A.; Akhmadaliev, S.; Belokonov, G.; Böttger, R.; Borany, J.; Kaever, P.; Meyer, M.; Noga, P.; Rugel, G.; Tiessen, C. J.; Wagner, N.; Wiedenbeck, M.; Wu, H.; Ziegenrücker, R.

The integration of an ion source having very high spatial resolution with a tandem accelerator is a long-standing concept for improving analytical selectivity and sensitivity by orders of magnitude [1]. Translating this design concept into reality has its challenges [e.g. 2,3], meaning this approach has seldom be used in the framework of geochemical research [e.g. 4].
Supporting a strong focus on natural, metallic and mineral resources, the Helmholtz Institute Freiberg for Resource Technology installed a so-called Super-SIMS at the Ion Beam Center at HZDR; this highly novel tool is devoted to the characterization of minerals and ores. The secondary ion beam from a CAMECA IMS 7f-auto is injected into the 6MV Dresden Accelerator Mass Spectrometry [5] facility, which quantitatively eliminates effectively all molecular species from the ion beam.
We will present the current status of this initiative and will report on the performance parameters of the Dresden Super-SIMS as well as first results from halogen determinations in sphalerite and galena. Furthermore, we will describe our concepts for the quantification of these data at the ultratrace level.
[1] Matteson (2008) Mass Spec Rev 27, 470-484. [2] Ender et al. (1997) NIMB 123 575-578. [3] Fahey et al. (2016) Anal Chem 88, 7145-7153. [4] Sie et al. (2000) NIMB 172, 228-234. [5] Rugel et al. (2016) NIMB 370 94-100.

Keywords: SIMS. Super-SIMS; Sphalerite; Halogen

  • Lecture (Conference)
    GOLDSCHMIDT 2019, 18.-23.08.2019, Barcelona, Spanien

Permalink: https://www.hzdr.de/publications/Publ-30578
Publ.-Id: 30578


Single-Shot Multi-keV X-Ray Absorption Spectroscopy Using an Ultrashort Laser-Wakefield Accelerator Source

Kettle, B.; Gerstmayr, E.; Streeter, M. J. V.; Albert, F.; Baggott, R. A.; Bourgeois, N.; Cole, J. M.; Dann, S.; Falk, K.; Gallardo González, I.; Hussein, A. E.; Lemos, N.; Lopes, N. C.; Lundh, O.; Ma, Y.; Rose, S. J.; Spindloe, C.; Symes, D. R.; Smid, M.; Thomas, A. G. R.; Watt, R.; Mangles, S. P. D.

Single-shot absorption measurements have been performed using the multi-keV x rays generated by alaser-wakefield accelerator. A 200 TW laser was used to drive a laser-wakefield accelerator in a modewhich produced broadband electron beams with a maximum energy above 1 GeVand a broad divergence of ≈15mrad FWHM. Betatron oscillations of these electrons generated1.2 0.2×106photons=eV in the5 keV region, with a signal-to-noise ratio of approximately 300∶1. This was sufficient to allow high-resolution x-ray absorption near-edge structure measurements at theKedge of a titanium sample in a singleshot. We demonstrate that this source is capable of single-shot, simultaneous measurements of both theelectron and ion distributions in matter heated to eV temperatures by comparison with density functionaltheory simulations. The unique combination of a high-flux, large bandwidth, few femtosecond durationx-ray pulse synchronized to a high-power laser will enable key advances in the study of ultrafast energeticprocesses such as electron-ion equilibration.

Permalink: https://www.hzdr.de/publications/Publ-30577
Publ.-Id: 30577


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