Practical trainings, student assistants and theses

Focused ion beam induced deposition (FIBID) allows the high resolution 3D printing of insulating, conducting, semiconducting and superconducting nanostructures with nearly arbitrary shape. However, while being similar to focused electron beam induced deposition (FEBID) the physical processes are different enough that successful printing strategies from FEBID can not be transferred one to one to the FIBID process. FEBID 3D Algorithm for Stream File generation (F3AST) is a software package developed by our partners at the Vienna University of Technology (TU Wien) that has been successfully used to predict growth parameters for FEBID. The package is agnostic to the underlying charged particle technique and should be capable—potentially with some minor modifications—to also be used for the FIBID process.

The objective of this master thesis is to obtain calibration parameters for FIBID using the helium ion microscope (HIM). The HIM is a focused ion beam (FIB) technique that allows the imaging and fabrication of nanostructures with an optimum resolution in the sub-nanometer range. It utilizes a 0.5 nm wide focused beam of He ions to raster scan the surface. This beam of energetic (typically 10 keV to 30 keV) ions can be used for high resolution imaging and materials processing. After successful calibration of the model complex 3D nanostructures will be created to demonstrate the applicability of the
F3AST software for ion beam based 3D printing.

The researchers at the TU Wien will provide a modified version of the F3AST code able to generate input files for the FIBICS NPVE pattern generator. HIM and a W(CO)6 precursor gas will be used to grow simple 3D structures for the calibration of the software. HIM and scanning electron microscope (SEM) imaging will be used to obtain high resolution images of the nanostructures and extract the required geometrical parameters which will be feed to the F3AST software. Transmission electron microscope (TEM) investigations will be used to assess the composition of selected structures.
After successful completion of the calibration complex 3D structures will be grown and their fidelity will be qualitatively and where possible quantitatively evaluated.

Bachelor in Physics or Materials Science
Ability to work in a nanotechnology lab using delicate equipment
Ability to create simple scripts using python or similar languages
Presentation and office skills

You will be embedded in the ion induced nanostructures group (FWIZ-N) at the ion beam center (IBC) of the HZDR.
The work is experimental and requires the presence at the IBC most of the time. Remote work is possible only partially upon case by case agreemnet.

Platinum group metals (PGMs), particularly rhodium (Rh), palladium (Pd), and platinum (Pt), are regarded as the "vitamins" used in the modern industry. PGMs are crucial components of fuel cells, jewelry, computers, cell phones, automobile catalysts, etc. Their distinct physical and chemical characteristics, such as their corrosion resistance, chemical inertia, and catalytic activity, account for their extensive application and create alloys to enhance the characteristics of other transition metals. Because of their unique properties, PGMs are seldom replaced with other elements or compounds in applications. However, PGM deposits in the earth's crust are limited. The utilization of secondary resources, such as recycling waste materials, could mitigate the issue of PGM scarcity. Several conventional methods have been used for recovering PGM from secondary sources. Among the separation technologies, membrane separation offers the continuous and selective recovery of individual PGMs with no adverse environmental effects.
Supported liquid membranes (SLM) are a chemically driven membrane method in which a solvent phase contains an organic ligand that preferentially binds to a metal in the feed solution. The metal-ligand combination is subsequently diffusively carried across the membrane support and discharged into the receiving phase. This approach is particularly useful for metal ion separation because the organic carrier generates lipophilic metal-organic ligand complexes. This continuous permeation technique combines extraction and stripping procedures with less chemical reagents. The objective of the thesis work deals with the employment of task-specific organic ligands as carriers in the supported liquid membrane system for the selective recovery of platinum group metals from secondary source leachates and understanding the transport mechanism using different mathematical modeling approaches.

• Conduct literature research on supported liquid membranes using various organic carriers and their applications in metal recovery
• Design and conduct laboratory experiments using supported liquid membrane studies using task-specific organic carriers with several parameters such as pH, concentration, the thickness of membrane, feed solutions, etc.
• Analyse and interpret data on membrane selectivity, flux rates, fouling resistance, and metal recovery efficiency
• Optimize experimental conditions targeting high recovery rates for Platinum, Palladium, and Rhodium
• Prepare a thesis report and present findings at conferences or workshops

• Bachelor's degree in Chemistry, Chemical Engineering, Environmental Engineering or related field
• Knowledge of hydrometallurgical processes and membrane separation technologies
• Knowledge of analytical techniques such as ICP-OES, AAS, or similar for metal concentration analysis
• Duration: 6 months
• Start Date: Start in 2025 is possible
• Funding: Remuneration according to HZDR internal regulations

Understanding the behaviour of fibre-laden drops is critical due to their presence in various industrial applications, including microelectronics fabrication, portable medical devices, and biofuel production. Our work focuses on the numerical simulation of fibre-laden drops, specifically investigating a single long deformable fibre within a drop impacting a solid substrate. The study aims to elucidate the dynamic interactions between the fibre and the drop. Key objectives include determining the changes in drop dynamics due to the fibre and observing fibre deformation upon impact.

This work will involve computational fluid dynamics (CFD), particularly finite volume methods, with a focus on interface tracking using the Volume of Fluid approach. The simulation will incorporate surface wettability to enhance our understanding of elasto-capillary interactions, offering insights relevant to real-world applications.

We are seeking a motivated student with prior experience in CFD (preferably OpenFOAM) or similar modelling software.

• Enrolled in a degree program such as Process Engineering, Mechanical Engineering, or Computational Modelling and Simulation
• Strong interest in particle-fluid dynamics and numerical simulations
• Preliminary experience in CFD, ideally with OpenFOAM
• Basic coding skills, preferably in C++

• Immediate start possible
• Duration of internship or thesis as per university regulations
• Remuneration available, scholarship holders (e.g. ERASMUS+) are welcome

Vanadium and manganese are essential in high-strength steel alloys, battery technologies (notably vanadium redox flow batteries), and various chemical processes. Due to their industrial significance, recovering these metals from residual wash water along with leaching acids promotes environmental and economic sustainability. This study aims to Investigate and optimize a membrane filtration (nanofiltration) process for the selective recovery of vanadium and manganese, along with acid reclamation, from both acid raffinate and residue wash water solutions. The research evaluates the performance of various membranes focusing on their efficiency in concentrating vanadium and manganese while minimizing the co-permeation of iron, calcium, and other minor elements.
The objective of the work is to develop a process yielding a concentrated solution rich in vanadium and manganese for further precipitation, solid-liquid separation and hydrometallurgical steps, ultimately facilitating the recovery of vanadium as vanadium pentoxide (V₂O₅). The outcomes will offer valuable insights into the design and operation of membrane filtration systems for recovering critical metals and leaching agents from industrial effluents, supporting sustainable resource management practices in the metallurgical industry.
In addition to metal recovery, this research addresses acid reclamation following solvent extraction (SX) and supported liquid membrane process, with the goal of reducing chemical consumption. Acid recovery from the raffinate will be also explored, with organic contaminants removed via sorbents, such as activated charcoal. The reclaimed acid can then be recycled back into the leaching circuit, establishing a more sustainable process loop.

• Educational Background: Bachelor's / Master’s degree in Metallurgical Engineering, Chemical Engineering, Environmental Engineering or related field

• Knowledge of hydrometallurgical processes and membrane separation technologies
• Basic laboratory skills and familiarity with equipment for Nano filtration, filtration testing, and solution analysis
• Knowledge of analytical techniques such as ICP-MS, AAS, or similar for metal concentration analysis

• Conduct a literature review on nanofiltration technology and its application in metal and acid recovery
• Design and carry out laboratory experiments with selected nanofiltration membranes, focusing on variables like pressure, pH, and concentration
• Analyze and interpret data on membrane selectivity, flux rates, fouling resistance, and metal-acid recovery efficiency
• Optimize filtration conditions through experimentation, targeting high recovery rates for vanadium and manganese
• Prepare a comprehensive thesis report and, if possible, present findings at relevant conferences or workshops

• Duration: 6 months
• Start Date: Start in 2025 is possible
• Funding: Remuneration according to HZDR internal regulations
• Supervision and Support: The candidate (f/m/d) will be supervised with regular guidance, training on laboratory protocols, and support in analytical techniques

Rare earth elements (REEs) are vital for several applications in various industrial sectors. Studies on REEs recovery from various secondary resources revealed that spent permanent magnets contain a significant amount (approximately 31-32 wt%) of rare earth metals. However, the presence of Fe poses a challenge for recovering REE from the leachate solution. It was observed that the REE will also co-precipitate with Fe upon precipitation, resulting in the loss of resources. To address this, an ion exchange method has been proposed for selective recovery of REE from leachate solutions. Our latest research reveals that selective ligands based on different media can recover REE from aqueous solutions even in the presence of other metals. The current study intends to develop task-specific resins based on selective ligands for effective REE recovery from spent NdFeB magnet leachate solutions as well as to investigate the efficiency of these resins for upscaling technology.

• Knowledge of hydrometallurgy and organic synthesis
• Experience in coordination chemistry, and technical chemistry is advantageous
• Good oral and written communication skills in English or German
• Ability to work independently and systematically

• Synthesis and purification of novel task-specific organic ligands
• Impregnation studies with various ion exchange resins
• Application of resins on recovery of rare earth metal ions from various spent magnet leachates and other sources
• Start date: Either an immediate start or a start in 2025 is possible
• Duration: 6 months
• Remuneration according to HZDR internal regulations

Computational fluid dynamics (CFD) is increasingly offering an alternative to experimental optimisation and improvement of both existing and new industrial processes or products, for which otherwise costly and time-consuming test and pilot plants are used. While the simulation of single-phase flows allows stable and reliable predictions, such numerical analyses for multiphase flows have so far only been validated and useful for selected cases due to their complexity and the large number of additional interactions.

In order to extend the applicability of numerical multiphase simulations, the Institute of Fluid Dynamics at the Helmholtz Centre Dresden-Rossendorf carries out experimental and numerical investigations in bubble columns in collaboration with the Institut de Mécanique des Fluides de Toulouse (IMFT) to better understand phase interaction phenomena. The current project focuses on the lateral lift force acting on millimetre-sized bubbles rising through a shear field, with particular interest in the influence of curved shear layers.

The objective of the proposed bachelor or master thesis is to performed direct numerical simulations at IMFT, Toulouse of well controlled configurations of a bubble (spherical or deformed) rising in a shear flow. The simulations will be compared against experiments performed at HZDR.

• Studies related to fluid dynamics (e.g. mechanical or process engineering, physics etc.)
• Experience in numerical simulation
• Good English or French language skills

• Working in a multidisciplinary and international team
• Place of work: IMFT in Toulouse
• Start: from March 2025
• Duration: approx. 6 months

Flowing foam is relevant to many different industrial applications, such as froth flotation in mineral processing, fire-extinguishing systems, or brewing beer and beverage production. In a scientific context, the rheological properties of foams are very complex and significantly different from those of Newtonian fluids such as water. As a result, despite numerous experimental and theoretical studies, the fluid dynamics of foams remain poorly understood.

This project focuses on a classical benchmark experiment: the flow around a cylindrical obstacle. To identify key parameters of flowing foam in this configuration, we use two unique radiographic measurement techniques. First, neutron radiography provides imaging measurements of the local liquid fraction of the flowing foam. Second, X-ray radiography with foam-tailored tracer particles allows to perform local velocity measurements in the flowing foam.

The following subtasks are mainly to be worked on:

• Assistance in preparing and performing the foam flow experiment in the X-ray laboratory at HZDR
• Analysis of the measurement data, including image processing and machine learning if applicable
• Documentation of the experiment and measurement results in written form

• Field of study: process engineering, fluid mechanics, or similar focus in chemistry or physics
• Experience with laboratory work, imaging measurement techniques or measurement data analysis is beneficial (e.g. using ImageJ, Matlab, Python)
• High motivation and interest in the subject
• Careful, structured and independent way of working
• Good oral and written communication skills in English or German
• Enjoyment of scientific work

• Working in a multi-disciplinary and international team
• Place of work: HZDR or TU Dresden
• Start: from January 2025
• Duration: min. 3 months
• Remuneration according to HZDR internal regulations

The application of phage surface display (PSD) technology has accelerated developments in the field of biomolecular sensors and materials science. A practical complement to this technology is Next-Generation Sequencing (NGS). In this combination, a more comprehensive view of biopanning rounds with a deep insight into the entire sequence space is made possible. It is possible to identify sequencing artefacts, determine sequence number and structure, recognize binding motifs and observe the evolution of the phage library over the course of an experiment. PSD in combination with biopanning is able to select candidates with high affinity and selectivity to the desired substrates from large peptide libraries. In practice, this specific enrichment of peptides leads to a reduction in library diversity. It should therefore be possible to better visualize this reduction in sequence space using data clustering methods in order to better understand distances between similar sequence families.
The student's task is to find suitable clustering methods for sequencing results from multiple phage display experiments and to apply these if necessary. It should be clear from the results to what extent the sequence space can be grouped into families and whether a mutation profile within and between these families is recognizable.

Prerequisite is a valid enrollment in a Master's program in bioinformatics, biotechnology, molecular biology, biochemistry, biology or a related natural science program. Furthermore:

• Interest in data cluster methods and bioinformatics
• Basic knowledge of bioinformatics, statistics, stochastics and clustering
• Experience with a programming language (e.g. Python, R, C, C++ or other)
• Ability to work independently and in a team

The topic is to be worked on as part of a Master's thesis in conjunction with a voluntary or mandatory internship. This results in a duration of 12 months. The duration can be extended or adjusted in consultation with the supervisor. We can offer you:

• An innovative multidisciplinary research environment related to relevant issues in resource technology
• Supervision by experienced scientists
• Practical experience in the field of bioinformatics and directed evolution

HZDR develops and operates two high-intensity lasers (DRACO and PENELOPE) as drivers for plasma-based accelerators — a novel concept for compact sources delivering ultra-short pulses of high-energy ions and electrons. We experimentally investigate plasma-based acceleration from the physical fundamentals to the application. - e.g., for free-electron lasers, as particle sources for radiobiological studies, or for neutron sources.
In order to realize such sources, a constant development and improvement of the laser system is paramount. One major point of interest for every high energy laser system is a well-defined beam shape. Within the scope of this work the already existing beam shaping at the PENELOPE laser on the basis of serrated apertures needs to be analyzed both numerically and experimentally. Alternative concepts to achieve suitable beam shaping capabilities shall be compared.

Focus of the work:

• Modeling of optical diffraction on serrated apertures, e.g., using Python
• Experimental verification of the diffraction pattern
• Data acquisition (near field, far field, propagation)
• Optimization of the shape of serrated apertures
• Introduction to alternative beam shaping concepts
• Data analysis and documentation

• Studies in Physics, Physical Engineering (or a comparable field of study)
• Interest in optics and laser physics-
• Interest in experimental work
• Interest in numerical methods in optics

• Duration: at least 3 months, the topic can easily be expanded into a thesis
• Start: anytime
• Workplace: Helmholtz-Zentrum Dresden – Rossendorf

HZDR develops and operates two high-intensity lasers (DRACO and PENELOPE) as drivers for plasma-based accelerators — a novel concept for compact sources delivering ultra-short pulses of high-energy ions and electrons. We experimentally investigate plasma-based acceleration from the physical fundamentals to the application.- e.g. for free-electron lasers, as particle sources for radiobiological studies, or for neutron sources.
In order to realize such sources, constant development and improvement of the laser system is paramount. The scope of this work lies in the analytical design, its optimization and the realization of a regenerative amplifier design. Such an amplifier is considered to replace one of the preamplifier stages (HGBA II) of the PENELOPE laser system. The amplifier design aims at >100 mJ of pulse energy at a repetition rate of 10 Hz, while the bandwidth supports laser pulses with a pulse duration of <150 fs.

Focus of the work:

• Design/modeling and optimization of the laser resonator using software support (e.g. RP Resonator or own script)
• Subsequent realization of the regenerative laser amplifier in the laboratory
• Data acquisition (near field, far field, spectrum)
• Optimisation of the laser pulse bandwidth and output energy
• Data analysis and documentation

• Studies in Physics, Physical Engineering (or a comparable field of study)
• Interest optics and laser physics
• Interest in experimental work

• Duration: at least 3 months, the topic can easily be expanded into a thesis
• Start: anytime
• Workplace: Helmholtz-Zentrum Dresden – Rossendorf

The research project ‘Development of tailor-made peptides for the treatment of polymers before the metallization of plastics’ aims to develop a biomolecule-based system that enables the metallization of high-quality engineering plastics. Using phage surface display technology (PSD), peptides are selected and their binding behavior is characterized using suitable technologies to quantify the surface interaction. Our industrial partner tests suitable peptide sequences in practical polymer coating and metallization experiments.

• Studying biotechnology, microbiology, chemistry, chemical engineering, or a comparable subject area
• Interest in practical, interdisciplinary research
• Knowledge of basic molecular biological and microbiological principles and working techniques
• Careful and independent way of working

• Work in an interdisciplinary and international team
• The workplace language is English
• Duration of the internship or thesis according to study regulations
• Start of work possible by February 2025 at the latest

The development of a multi-channel flow body sensor according to patent WO 2010/069307 A1 aims to quantify the gas content in flow-carrying components. A decisive advantage of this sensor lies in its optical measuring principle, which is based on fiber-optic coupling and the analysis of the light output signal. This avoids electrical potentials in the measuring area, offering significant advantages over electrical measuring methods (intrinsic safety), especially for explosive mixtures.

Preliminary tests at the Institute for Experimental Fluid Dynamics at the Helmholtz Center Dresden-Rossendorf on gas-liquid flows showed that a clear binarization of the sensor output signal can be achieved due to the capillary effects in narrow channels and the different refractive indices of the gas and liquid phases. Building on previous work with a single-channel sensor prototype based on a polymer optical fiber (POF) with a diameter of 1 mm, the following tasks must be completed as part of further research.

Tasks:

• Adjusting the POF diameter to 1.5 mm in the single-channel configuration.
• Conducting experimental investigations of the new single-channel prototype using the already developed test system and evaluation programs.
• Designing a multi-channel sensor body for gas content measurements in the system.
• Developing a transition adapter to optimize the flow distribution between the DN10 flow pipe and the sensor body.

• Students majoring in fields such as process engineering, mechanical engineering, or chemical engineering.
• Interest in fluid mechanics and the development of measurement technology.
• Experience with 3D CAD tools.
• Basic knowledge of Python programming

Start date: 01.01.2025
Duration: according to the respective study regulations

1D- und 2D-Ramanspektroskopische Meßreihen oder auch Maps liefern detaillierte ortsaufgelöste chemische Informationen über die untersuchten Proben. Damit kann z. B. die Komponentenverteilung in Stoffgemischen quantitativ bestimmt oder die Homogenität einphasiger Proben gezeigt werden. Andererseits lassen sich lokale Strukturveränderungen, Spannungszustände, Stapelfolgenänderungen in 2D-Materialien und Punktdefekte charakterisieren. Voraussetzung dabei ist eine möglichst engmaschige Datenerfassung bis hin zur Auflösungsgrenze der verwendeten Laserstrahlung sowie eine große Anzahl an Messpunkten. Mit modernen Spektrometern sind Messzeiten im Sekundenbereich gut realisierbar. Die Umsetzung der spektroskopischen in eine chemische Information erfordert dann die Extraktion von Parametern wie Schwingungsfrequenz, Intensität und Linienbreite durch Spektrenanpassung. Die Gerätesoftware bietet dafür nur eingeschränkte Möglichkeiten.
Im Rahmen einer Graduierungsarbeit oder Hilfstätigkeit soll in Zusammenarbeit mit dem HZDR-Rechenzentrum ein Auswertealgorithmus für die automatisierte Auswertung von 1D- und 2D-Ramanspektroskopischen Meßreihen entwickelt, an Beispielen getestet und dokumentiert werden.

1. Studium der Werkstoffwissenschaften, Physik oder Chemie
2. Interesse, Freude und Befähigung für wissenschaftliche Arbeit
3. Grundkenntnisse in Programmierung und sicherer Umgang mit Büro- und wissenschaftlicher Software
4. Sehr gute Englisch-Kenntnisse

Die Arbeit ist in die umfangreichen Aktivitäten der Abteilung Nanoelektronik (FWIO) zu 2D-Werkstoffen eingebettet. Sie kann jederzeit aufgenommen werden.

Wir beschäftigen uns mit der Entwicklung von PET-Radiotracern, die Rezeptoren im Tumormikromilieu (TME = tumor microenvironment) für die Diagnostik und Therapie von Krebs sichtbar machen. Dazu werden geeignete tumoraffine Leitstrukturen identifiziert (niedermolekulare organische Moleküle, Peptide und Peptidomimetika), synthetisiert und mit einem geeigneten Radionuklid kovalent (z. B. Fluor-18, Iod-123) oder über einen Chelator (z. B. Gallium-68, Lutetium-177) markiert. Diese Radioliganden werden in vitro an Tumorzelllinien und in vivo im Tiermodell hinsichtlich einer Anwendung in der Nuklearmedizin getestet. Langfristiges Ziel ist die Translation der entwickelten Radiotracer in die Klinik als Diagnosewerkzeug (PET/CT) oder nach Markierung mit einem Beta- oder Alphastrahler für die Endoradiotherapie von Tumorerkrankungen.
Im Rahmen eines Studentenpraktikums oder einer Bachelor- oder Masterarbeit sollen organische Wirkstoffmoleküle synthetisiert und für eine anschließende radiochemische Markierung modifiziert werden. Die neuen Radioliganden werden dann biologisch in vitro und in vivo untersucht.

• Studium der Chemie
• Gute Noten in organischer Synthesechemie
• Fähigkeit sich in ein interdisziplinäres Wissenschaftler-Team einzugliedern
• Bereitschaft zum Umgang mit Radioaktivität
• Gute Kenntnisse der deutschen und englischen Sprache

• Beginn nach Absprache jederzeit möglich
• Praktikumsdauer mind. 4 Wochen, mit möglichst täglicher Anwesenheit

Turmkraftwerke stellen die neueste Generation von Anlagen zur solarthermischen Elektroenergieerzeugung dar (s. Abbildung). Großflächige Spiegelanordnungen konzentrieren Sonnenlicht auf einen zentralen Absorber, wo es in Wärmeenergie umwandelt wird, die dann auf ein Wärmeträgermedium übertragen wird. Gegenüber der Photovoltaik hat die Solarthermie den inhärenten Vorteil, Energie zu speichern und bei Bedarf bereit zu stellen. Die Herausforderung für die weitere Erhöhung des Wirkungsgrades von Solarkraftwerken besteht in der Entwicklung von Werkstoffen mit einer Temperaturstabilität bis zu 800 °C an Luft.
Im Rahmen von Graduierungsarbeiten und Hilfstätigkeiten sollen thermisch stabile Beschichtungen für die Kernkomponenten von Solarturmkraftwerken entwickelt und getestet werden. Dabei kommen modernste in situ und ex situ Methoden wie Magnetronsputtern, Ellipsometrie, UV-vis-NIR-FTIR-Reflektometrie und Ramanspektroskopie zur Anwendung.
Zu diesem Themenbereich werden u. a. die folgenden Aufgabenstellungen angeboten:
i) Schichtabscheidung und Optimierung der optischen und elektrischen Eigenschaften von transparenten leitfähigen Oxiden für Solarkraftwerke;
ii) Entwicklung von neuartigen Absorber- und Wärmespeicherwerkstoffen für Solarkraftwerke;
iii) Design und Simulation von solarselektiven Beschichtungen für Solarkraftwerke.

Zur Charakterisierung der untersuchten Materialien stehen modernste in situ und ex situ Analysemethoden zur Verfügung. Die Arbeiten können jederzeit aufgenommen werden.

1. Studium der Werkstoffwissenschaften, Physik oder Chemie
2. Interesse, Freude und Befähigung für experimentelle wissenschaftliche Arbeit
3. Grundkenntnisse in Programmierung und sicherer Umgang mit Büro- und wissenschaftlicher Software
4. Sichere Englischsprachkenntnisse (fließend oder besser)

Internationale Forschungsumgebung, ortsübliche Aufwandsentschädigung