PhD student (all genders) 65% Ref. No.: Reference number: 26.15-1700

The GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt operates PHELIX (Petawatt High-Energy Laser for Heavy-Ion Experiments), one of the leading high-power laser facilities for research in high-energy-density physics, laser-driven particle acceleration, and advanced plasma diagnostics. Closely connected to GSI’s accelerator infrastructure and the international large-scale project FAIR (Facility for Antiproton and Ion Research), currently under construction, PHELIX offers unique experimental opportunities within an interdisciplinary and international environment.

Within this framework, the DFG-funded project “Ultra-Bright Laser-Driven MeV Particle and Radiation Sources via Direct Laser Acceleration of Electrons in Foams for Multidisciplinary Research” investigates Direct Laser Acceleration (DLA) of electrons in previously largely unexplored intensity regimes: (a) near-relativistic intensities with large focal spots and (b) ultra-high relativistic intensities. Building on earlier PHELIX experiments and numerical simulations, near-critical-density targets are employed (case a), as well as nanostructured targets (case b). The goal is to deepen the understanding of the underlying acceleration processes and to develop an electron source with increased energy and charge, as well as to enable secondary photon and neutron sources based on the accelerated electron beam.

For the Plasma Physics Department we are looking for a

PhD student (all genders) 65%

Reference number:

• Develop and implement diagnostics to measure the electron energy and angular distribution for experiments at European short-pulse PW laser facilities operating at ultra-high relativistic intensities
• Design and construct a scintillator-based spectrometer for high-repetition-rate operation
• Plan and conduct experiments using low-density foams as targets, and contribute to the setup, operation, and evaluation of measurement campaigns
• Investigate and optimize DLA-based synchrotron radiation (betatron radiation) and inverse Compton scattering
• Become familiar with and apply Monte Carlo simulations (GEANT4 or FLUKA) to evaluate gamma-ray spectra from measurement data
• Generate and characterize bremsstrahlung in the giant dipole resonance regime (GDR > 7.5 MeV), as well as isotope production and ultra-high neutron fluxes
• Perform nuclear activation measurements on medium/high-Z materials and analyze activation products
• Operate and analyze measurements with a high-purity germanium detector (HPGe)
• Document, present, and publish results, and contribute to scientific publications

Required

• Master’s degree in Physics
• Very good programming skills (e.g., Python/C++)
• Basic knowledge of numerical analysis
• Motivation for experimental work in an international team
• Very good English skills (B2–C1)
• Experience with 2D PIC simulations and Monte Carlo codes (GEANT4 or FLUKA)
• Experience with scintillator-based diagnostics and fast cameras (sCMOS, ICCD) for high-repetition-rate experiments
• Additional experience in timing/synchronization and automated data analysis is an advantage

We offer you a versatile, varied, and challenging position at an exceptionally well-equipped workplace with interesting and diverse responsibilities. Teamwork and a strong commitment to continuous professional development are essential to us.

GSI also provides a wide range of benefits to support work–life balance, including services for reconciling family and career, occupational health management programs, employee social counseling, personal training and qualification opportunities, a job ticket (public transport), supplementary pension benefits, additional company leave, and access to the “Schnelle Ionen” company sports club.

The contract is limited for 3 years. The salary is based on the collective agreement for public employees (TVöD). Starting date is 1 st April 2026.

GSI supports the vocational development of women. Therefore, women are especially encouraged to apply for the position.

Handicapped persons will be preferentially considered when equally qualified.

If you have any questions regarding this position, please contact Prof. Olga Rosmej (o.rosmej(at)gsi.de).

If you are interested in working in an exceptional international, highly technical environment, please send your complete application documents, with two references and details of your earliest possible starting date, quoting thePosting-ID by10 st of March 2026 at the latest via our online portal: