Practical trainings, student assistants and theses

Direct numerical simulation of the lift force acting on a bubble rising in a shear flow (Id 445)

Bachelor theses / Master theses / Diploma theses

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.

Department: Computational Fluid Dynamics

Contact: Dr. Hessenkemper, Hendrik, Dr. Lucas, Dirk

Requirements

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

Conditions

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

Online application

Please apply online: english / german

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Neutron and X-ray radiographic study of foam flowing around a cylinder (Id 444)

Bachelor theses / Master theses / Diploma theses / Compulsory internship

Foto: Foam flowing aorund cylinder ©Copyright: Artem SkrypnikFlowing 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

Institute: Institute of Fluid Dynamics

Contact: Dr. Lappan, Tobias, Skrypnik, Artem

Requirements

  • 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

Conditions

  • 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

Online application

Please apply online: english / german

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Beam shaping on the PENELOPE high-energy laser system (Id 439)

Bachelor theses / Master theses / Diploma theses / Student Assistant / Research Assistant

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

Department: Laser Particle Acceleration

Contact: Dr. Albach, Daniel, Dr. Löser, Markus

Requirements

  • 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

Conditions

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

Links:

Online application

Please apply online: english / german

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Laser amplifier development on the PENELOPE high-energy laser system (Id 438)

Bachelor theses / Master theses / Diploma theses / Student Assistant / Research Assistant

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

Department: Laser Particle Acceleration

Contact: Dr. Löser, Markus, Dr. Albach, Daniel

Requirements

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

Conditions

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

Links:

Online application

Please apply online: english / german

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Development and experimental investigation of a multi-channel flow body sensor (Id 421)

Bachelor theses / Master theses / Diploma theses / Compulsory internship

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.

Department: Fluid process engineering

Contact: Condriuc, Ivan, Dr. Kipping, Ragna

Requirements

  • 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

Conditions

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

Online application

Please apply online: english / german

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Student internship, research assistant, school practical training, master/diploma thesis, compulsory internship (Id 407)

School practical training / Student practical training / Bachelor theses / Master theses / Diploma theses / Student Assistant / Holiday job / Compulsory internship / Volunteer internship / Research Assistant

At Helmholtz-Zentrum Dresden-Rossendorf (HZDR), over 1,500 employees from more than 70 nations are conducting cutting-edge research in the fields of ENERGY, HEALTH, and MATERIALS to address the major challenges facing society today.
The Center for Advanced Systems Understanding (CASUS), founded in Görlitz in 2019, is a German-Polish interdisciplinary research center focusing on data-intensive digital systems.
CASUS offers student internships in a wide range of scientific fields. You are welcome to apply and join CASUS if you are interested in gaining knowledge in the following research areas:

  • Theoretical Chemistry
  • Earth System Science
  • Systems Biology
  • Digital Health
  • Computational Radiation Physics
  • Theory of complex systems
  • Dynamics of Complex Living Systems
  • Machine Learning for Infection and Disease
You can also apply to join our administrative team as a student assistant.

Institute: CASUS

Contact: Dr. Mir Hosseini, Seyed Hossein, Mazur, Weronika, Dr. Calabrese, Justin, Dr. Martinez Garcia, Ricardo, Dr. Bussmann, Michael, Dr. Cangi, Attila, PD Dr. Kuc, Agnieszka Beata, Dr. Yakimovich, Artur, Dr. Knüpfer, Andreas, Dr. Schlechte-Welnicz, Weronika

Requirements

  • Student in computer science, physics, chemistry, or related fields
  • Student already enrolled at the university in Germany, Poland or Czech Republic (close exchange and attendance in the office preferable and combined with the moblie working from Germany combinable)
  • Eager to learn new skills
  • Strong motivation to work in a collaborative environment
  • Preliminary experience in code development is an advantage
  • Excellent communication skills in English and/or German or Polish

Conditions

  • A vibrant research community in an open, diverse and international work environment
  • Scientific excellence and extensive professional networking opportunities
  • A wide range of qualification opportunities
  • We support a good work-life balance with the possibility of part-time employment, mobile working and flexible working hours
  • Either an immediate start or a start in 2024 is possible
Please submit your application (including a one-page cover letter, CV, academic degrees, transcripts, etc.) online on the HZDR application portal

Online application

Please apply online: english / german

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Automatisierte Auswertung von 1D- und 2D-Ramanspektroskopischen Meßreihen (Id 393)

Bachelor theses / Master theses / Diploma theses

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.

Department: Nanocomposite Materials

Contact: Dr. Krause, Matthias

Requirements

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

Conditions

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

Online application

Please apply online: english / german

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Medizinische Chemie/ Organische Synthese neuer Radioliganden für die Krebsdiagnostik und -therapie (Id 295)

Student practical training / Bachelor theses / Master theses

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.

Department: Medical Radiochemistry

Contact: Dr. Stadlbauer, Sven, Sachse, Frederik

Requirements

  • 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

Conditions

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

Online application

Please apply online: english / german

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Materials for new solar power plants (Id 241)

Bachelor theses / Master theses / Diploma theses

Foto: Solar thermal power plant ©Copyright: @AbengoaTurmkraftwerke 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.

Department: Nanomaterials and Transport

Contact: Dr. Krause, Matthias

Requirements

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)

Conditions

Internationale Forschungsumgebung, ortsübliche Aufwandsentschädigung

Online application

Please apply online: english / german

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