Postdoc Positionen
Postdoctoral Researcher (f/m/d) for the Development of an Experimental Platform for Laser Beam Stabilization
The GSI Helmholtz Centre for Heavy Ion Research in Darmstadt operates one of the world’s leading particle accelerator facilities for fundamental research. Together with international partners, GSI is currently building the new FAIR (Facility for Antiproton and Ion Research), one of the largest research projects worldwide. GSI and FAIR offer the opportunity to work in an international environment with a dedicated team committed to world-class science.
Within the research project Adaptive Laser Architecture Development and INtegration(ALADIN), we are looking to fill the following position as soon as possible:
Postdoctoral Researcher (f/m/d) for the Development of an Experimental Platform for Laser Beam Stabilization
Reference Number: 25.71-1700
Project Context (ALADIN & PHELIX):
Inertial Confinement Fusion (ICF) relies on laser-driven compression of fuel capsules. Future fusion energy facilities (IFE) will require highly stable high-power laser systems with hundreds of beamlines. To meet this demand, ALADIN is exploring adaptive control architectures for the active stabilization of large-scale laser systems.
The work package LAOTSE (Laser Adaptive Optics Testbed for StabilizationExperiments) will establish an experimental platform to emulate dynamic beamlineprocesses in high-energy laser systems. This setup will be used to test advanced adaptive optics concepts and evaluate novel control architectures for next-generation IFE systems.
Your Responsibilities:
- Development of an optical testbed that realistically emulates high-energy laser beamlines and their dynamic influences
- Integration of diagnostic and actuator technologies to experimentally evaluate computer-controlled stabilization concepts under realistic conditions
- Development and implementation of software interfaces to connect the platform to a higher-level control system (TANGO Controls)
- Testing and validation of novel control mechanisms with direct relevance to future high-power laser systems for fusion research.
Your profile:
- Doctorate (PhD) in physics, engineering, optics, or a related field
- Solid expertise in laser physics, optical metrology and adaptive optics
- Experience with building complex optical setups in experimental environments
- Programming knowledge in Python and familiarity with TANGO Controls is advantageous
- Ability to work independently on scientific tasks, along with strong team and communication skills
- Excellent German and English language skills, spoken and written.
We Offer:
- Employment at GSI conducting research within the ALADIN project
- Research at the interface of fundamental and applied laser physics
- Opportunity to build an experimental infrastructure of international relevance for fusion energy
- Involvement in an innovation-driven greenfield project within a committed research team
- Publication of research results in renowned peer-reviewed journals and presenting findings at international conferences
- Career development and training opportunities in an excellent scientific environment
- Flexible working arrangements, including up to two days of remote work per week.
The duration of the position is limited to an initial term of 42 months.
The salary is based on the German civil service employees (Tarifvertrag für den öffentlichen Dienst - TVöD (Bund)).
GSI supports the professional development of women. Therefore, women are especially encouraged to apply for the position.
Severely handicapped persons will be preferentially considered when equally qualified.
For more information on FAIR and GSI, please visit www.gsi.de and www.fair-center.eu.
If you have questions, feel free to contact Dr. Jonas Ohland (j.b.ohland(at)gsi.de, Tel. +49 6151-71-3381).
If you see this role as an exciting personal challenge and would like to work in an exceptional scientific environment, please submit your complete application, earliest possible start date, and the reference number25.71-1700, no later than 14.08.2025 via our
PhD Position (f/m/d) for Aberration Modeling in High-Energy Lasers part-time (65%)
The GSI Helmholtz Centre for Heavy Ion Research in Darmstadt operates one of the world’s leading particle accelerator facilities for fundamental research. Together with international partners, GSI is currently building the new FAIR (Facility for Antiproton and Ion Research), one of the largest research projects worldwide. GSI and FAIR offer the opportunity to work in an international environment with a dedicated team committed to world-class science.
For the research project Adaptive Laser Architecture Development and INtegration (ALADIN), we are seeking, as soon as possible, a
PhD Position (f/m/d) for Aberration Modeling in High-Energy Lasers
part-time (65%)
Reference Number: 25.70-1700
Project Context (ALADIN & PHELIX)
In inertial confinement fusion, fuel capsules are compressed using laser energy until nuclear fusion is initiated. For use in commercial fusion power plants, highly stable laser beams are essential, which in turn require novel beam control concepts. Developing these concepts requires a fundamental understanding of dynamic aberrations and the ability to replicate them in test setups. This is the core focus of the advertised PhD project.
The experimental work will be conducted on the PHELIX laser at GSI Darmstadt, Germany’s only high-energy laser system based on Nd:glass technology. As part of the project, a permanent testbed for beam control development will be established, which the PhD candidate will actively help to design and construct.
Your Responsibilities:
- Analysis and modeling of dynamic aberrations in various high-power laser systems across Europe
- Development of a parametric real-time model to simulate beam dynamics
- Experimental validation of the model within the newly built ALADIN testbed
- Participation in measurement campaigns at the PHELIX laser and other major European research facilities
- Integration of the model into a control system for adaptive laser optics.
Your Profile:
- Completed university degree in physics, engineering, optics or a related field
- Experience or strong interest in laser physics, adaptive optics or optical metrology
- Programming skills (preferably in C++, Python, LabVIEW, Bash)
- Team spirit and a high level of initiative in an experimental setting
- Willingness to travel for short-term research stays abroad (max. 2 weeks per stay)
- Driving license (Class B)
- Language skills: Fluency in German and English.
We Offer:
- Employment at GSI with the PhD awarded by TU Darmstadt, supervised by Prof. Vincent Bagnoud’s group
- Research at the interface between fundamental and applied laser physics
- Work on an innovation-driven greenfield project within a young, dynamic research team
- Direct involvement in international collaborations with European research institutions
- Contribution to a long-term research effort with significance for the future of fusion energy
- Opportunity for professional and personal development in a high-caliber scientific environment
- Flexible work arrangements including up to two remote work days per week
The duration of the position is limited to an initial term of 36 months.
The salary is based on the German civil service employees (Tarifvertrag für den öffentlichen Dienst - TVöD (Bund)).
GSI supports the professional development of women. Therefore, women are especially encouraged to apply for the position.
Severely handicapped persons will be preferentially considered when equally qualified.
For more information on FAIR and GSI, please visit www.gsi.de and www.fair-center.eu.
For inquiries, please contact Dr. Jonas Ohland (j.b.ohland(at)gsi.de), Tel. +49 6151-71-3381).
If you see this role as an exciting personal challenge and would like to work in an exceptional scientific environment, please submit your complete application, earliest possible start date, and the reference number 25.70-1700 no later than 14.08.2025 via our online application portal:
Bachelor-/Masterthesis
Motivation:
Although Gaussian beams have excellent properties for beam transport, it is common practice in high-energy laser systems to use a uniform spatial energy distribution, a so-called flat-top beam. This has the advantage that, for example, the damage thresholds of optics are only reached at higher energies and this parameter can therefore be maximised. Another application is the use of such a beam profile for the pump beam of an optical parametric amplifier. This allows a more homogeneous amplification factor to be achieved over the entire beam profile, which also leads to higher amplification efficiency.
Tasks:
- Design of a beam-forming telescope with the following criteria:
- Design of an optical system for converting Gaussian beams into Flattop beams and vice versa
- Simulation of the telescope: ray tracing, phase calculation, beam propagation
- Determination of the beam sizes and the permitted variation, with additional estimation of the susceptibility to adjustment
- Estimation of the image-free propagation of the generated beam
- Design of a beam-forming telescope and its characterization:
- Efficiency
- Stability
- Residual ripple in the flattop
- susceptibility to adjustment
Goals:
- Design and construction of a beam-forming telescope
- Characterization of the telescope
Useful prior knowledge / prerequisites:
- Optics and optical design
- Programming skills for modeling and analysis of generate data (e.g. Python, Matlab, Zemax…)
Literatur:
- https://www.spiedigitallibrary.org/conference-proceedings-of-spie/9626/96261W/Modular-optical-design-for-flexible-beam-shaping-of-a-top/10.1117/12.2191062.short
- iopscience.iop.org/article/10.1088/1742-6596/276/1/012171/pdf
If you are interested in this work, please write a mail to::
Development of a spectrometer for temperature measurement via Thomson scattering
Master thesis
Motivation:
The temperature inside a plasma is not easy to measure, because it is often shielded by the emission of the plasma corona. A solution is to use a laser as a probe to interrogate the plasma at the desired location and analyze the scattered light spectrally. Here, it is advantageous to use a short laser pulse to gain time resolution and a short wavelength, because it has a better penetration depth in dense plasmas
Topic description:
The topic of the master thesis would be the development of the light collecting optical system, signal transport and UV spectrograph for the target station HHT at GSI. The following topics will be covered in the framework of the thesis work:
- laser-plasma interactions: Thomson scattering
- optical design and beam transport, optical imaging
- spectrometer design
- data acquisition (Labview), data analysis (Python, Labview)
- experimental validation
If you are interested in this work, please write a mail to:
v.bagnoud(at)gsi.de
Bachelorthesis
Motivation:
With the achievement of ever higher intensities, the measurement and optimisation of the temporal contrast is one of the most important tasks of modern laser systems. In addition to "quasi"-constant background noise (amplified spontaneous emission) and a rapidly increasing rising edge, so-called prepulses also play a role. Since the aforementioned disturbances in the temporal pulse profile can already generate plasmas and thus render experiments unusable, it is essential to avoid them. The occurrence of prepulses in particular is a rather dynamic process, as even slight changes in the system can generate them.
Tasks:
- Analysis of existing contrast measurements
- Calculate the optical path length of existing pre- and post-pulses
- Estimate which optics / optical systems can cause these
Goals:
- Identification of pre- and post-pulses in the laser system
- Localization of the points of origin by measuring the contrast at different points in the system
Useful prior knowledge / prerequisites:
- Basics of optics
- Programming skills for data analysis (e.g. Python)
Literature:
- https://link.springer.com/article/10.1007/s00340-019-7172-5
- https://www.cambridge.org/core/journals/high-power-laser-science-and-engineering/article/enhancement-of-prepulse-and-picosecond-pedestal-contrast-of-the-petawatt-jkarenp-laser/FD2BF3EAEFA3AC0ED82D7E49C8B87CE8
If you are interested in this work, please write a mail to:
Masterarbeit
Motivation:
Mit der rapiden voranschreitenden Entwicklung im Bereich der Laser mit hoher mittlerer Leistung und der Verbesserung von Laser-getriebenen Sekundärquellen werden Anwendungsgebiete im Bereich der industriellen Entwicklung und interdisziplinären Forschung relevanter. Ein vielversprechendes Gebiet ist hier die Erzeugung von Gamma- und Neutronenquellen welche für das Durchleuchten verschiedener Materialen genutzt werden kann um dessen Inhalt und Zusammensetzung zu Untersuchen. Außerdem können Laser-getriebene Elektronen- und Ionenquellen für die Erzeugung von Radioisotopen verwendet werden welche in der medizinischen Forschung benötigt werden. Aufgrund der Flexibilität von solchen Quellen haben sie einen großen Vorteil gegenüber konventionellen Beschleunigern die typischerweise für die medizinisch-relevanten Isotope verwendet werden. Ziel dieser Arbeit ist es daher die Nutzbarkeit verschiedener Sekundärquellen für die Erzeugung von Gamma- und Neutronenstrahlen sowie die Erzeugung von Radioisotopen für die Medizinforschung mittels Simulationen zu untersuchen und die Prozesse zu optimieren.
Aufgaben:
- Aufsetzen von Monte Carlo Simulationen mittels des Codes FLUKA
- Simulation der Wechselwirkung von Elektronen und Ionenstrahlen mit verschiedenen Konvertierungsmaterialien und Geometrien
- Teilnahme an einer Experimentellen Kampagne zur Erzeugung von Radioisotopen an PHELIX
Ziele:
- Simulation der Gamma- und Neutronenkonversion mit verschiedenen Sekundärquellen
- Bestimmung der Ausbeute von speziellen Radioisotopen mit verfügbaren laser-getriebenen Sekundärquellen
- Optimierung der Gamma- und Neutronenausbeute anhand der Konverter Parameter
- Vergleich mit experimentellen Ergebnissen mit den Simulationen
Nützliche Vorkenntnisse:
- Programmierkenntnisse (z.B. Python)
- Erfahrungen mit Monte Carlo Simulationen
Literatur:
- G. Battistoni, et al., Annals of Nuclear Energy, 82, 2015 DOI doi.org/10.1016/j.anucene.2014.11.007.
- Z. Sun, et al., AIP Advances11, 040701, 2021 DOI
- https://doi.org/10.1063/5.0042796
Bei Interesse an der Arbeit schreibe bitte eine Mail an:
