Physicist or Engineer (all genders)

The Helmholtz Institute Mainz (HIM) is a physics research institute dedicated to investigating the structure, symmetry and stability of matter and antimatter. It is an institutional collaboration between Johannes Gutenberg University Mainz and the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt. HIM combines the academic environment of a university with the scientific opportunities offered by an internationally renowned large-scale ion accelerator centre. FAIR (Facility for Antiproton and Ion Research), one of the world's largest research projects, is currently under construction in Darmstadt. For the ACID1 department, we are seeking, at the earliest possible date, a Physicist or Engineer (all genders) Reference number to contribute to the development and construction of the superconducting linear accelerator HELIAC (HElmholtz LInear ACcelerator). The position combines independent design and scientific-technical responsibilities with a substantial amount of hands‑on work on superconducting cavities and cryomodule components. Key activities include the development of assembly and auxiliary fixtures, cleanroom assembly, and the execution of quality‑critical surface preparation processes.

Your tasks:

• Performing and further developing the surface preparation of superconducting cavities, particularly by means of high-pressure rinsing (HPR), including the preparation, operation and optimisation of quality-relevant process steps
• Developing and designing assembly and auxiliary fixtures for superconducting cavities and cryomodule components, including CAD modelling and technical dimensioning; preparing manufacturing documentation and supporting the fabrication, testing and optimisation of the fixtures
• Planning and optimising assembly procedures and providing technical guidance to the technicians involved; hands‑on assembly, disassembly, alignment and integration of superconducting cavities and associated cryomodule components in the cleanroom
• Setting up, adapting, testing, servicing and maintaining assembly, preparation and test equipment; analysing technical problems and implementing appropriate improvement measures
• Scientifically evaluating, documenting and publishing the results obtained, and contributing to scientific publications, technical reports and presentations at scientific conferences

Your profile:

• A completed university degree (Master's degree or German university Diplom) in mechanical engineering, mechatronics, physics, engineering physics or a comparable discipline
• A strong practical and hands‑on technical orientation, together with the willingness to independently carry out assembly, alignment and installation work on scientific and technical components and systems
• Good knowledge of and practical experience in CAD design; knowledge of engineering mechanics, mechanical dimensioning and finite element analysis (FEA) is an advantage
• Experience in the setup, assembly or operation of complex technical or experimental systems, as well as the ability to provide technical guidance and coordinate technical work
• A careful, structured and responsible working approach, a strong commitment to quality, and willingness to work in a cleanroom environment
• Knowledge of cleanroom, vacuum, surface, cryogenic or accelerator technology is an advantage, but is not a prerequisite
• Good written and spoken German and English, as well as the ability to prepare and present scientific and technical documentation

We offer a varied and responsible position in a dynamic and well-equipped research environment. The position is limited to a term of three years. Remuneration is based on the German Federal Government's Collective Agreement for the Public Service (TVöD Bund).

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.

Further information about HIM, GSI and FAIR is available at and

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