Your responsibilities

The Radio Frequency Group (RF) of CERN's Accelerator Systems Department (SY) is seeking an Applied Physicist to join the Superconducting Radio Frequency Cavity Technology Section (SRF). You will work with a small, focused team to investigate and leverage the superconducting properties of thin and multilayer film structures and improve the performance of SRF cavities.

The primary focus is on the manipulation and expulsion of magnetic flux vortices within the superconducting film and assessing the role of thermal currents in their dynamics. This is a challenging, multi-disciplinary project where you will take a lead role in developing the underlying physical model, operating CERN's Magnetic Flux Lens (MFL) setup, and analysing the resulting data. Ultimately, your work will contribute to a pragmatic understanding of superconductivity with significant application to SRF research.

Of particular interest is the study of flux dynamics in thin film Niobium (Nb) on Copper substrates, as well as more novel materials such as Nb3Sn and NbTiN, in Superconductor-Insulator-Superconductor (SIS) structures.

Your activities will include:

• Model Development: develop and refine the physical description of the dynamics of superconducting films at the superconducting transition.
• Multi-physics Simulations: perform advanced simulations of superconducting films to understand their complex magneto-thermal dynamics.
• Experimental Operations: conduct direct measurements of magneto-thermal dynamics in thin-film superconductors, with CERN's MFL setup.
• Data Analysis and Correlation: analyse experimental data from MFL measurements to correlate findings with predictions from physical models.
• SRF Cavity Integration: extension of the sample-based study to SRF cavity geometries and the isolation of substrate dependencies.

This role provides a broad, multidisciplinary environment that bridges material science and SRF accelerator cavities, offering significant opportunities for professional growth over a diverse experience base.

Your profile

Skills:

• Multi-physics simulations;
• Knowledge of superconducting materials;
• Operation of experimental setups;
• Data analysis;
• Good communication skills;
• Spoken and written English, with a commitment to learn French.

Eligibility criteria:

• You are a national of a CERN Member or Associate Member State.
• You have a professional background in Radio-frequency, Superconductivity (or a related field) and have either:
• a Master's degree with 2 to 6 years of post-graduation professional experience;
• or a PhD with no more than 3 years of post-graduation professional experience.
• You have never had a CERN fellow or graduate contract before.

Additional Information

Job closing date: 19.10.2025 at 23:59 CEST.

Contract duration: 24 months, with a possible extension up to 36 months maximum.

Working hours: 40 hours per week

Target start date: 01-January-2026

Job reference: SY-RF-SRF-2025-149-GRAP

Field of work: Applied Physics

What we offer

• A monthly stipend ranging between 6287 and 6911 Swiss Francs per month (net of tax).
• Coverage by CERN's comprehensive health scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
• Depending on your individual circumstances: installation grant; family, child and infant allowances; payment of travel expenses at the beginning and end of contract.
• 30 days of paid leave per year.
• On-the-job and formal training at CERN as well as in-house language courses for English and/or French.

About us

At CERN, the European Organization for Nuclear Research, physicists and engineers are probing the fundamental structure of the universe. Using the world's largest and most complex scientific instruments, they study the basic constituents of matter - fundamental particles that are made to collide together at close to the speed of light. The process gives physicists clues about how particles interact, and provides insights into the fundamental laws of nature. Find out more on http://home.cern.

We are on a Quest. A Journey into discovery like no other. Bring your expertise to our unique work and develop your knowledge and skills at pace. Join world-class subject matter experts on unique projects, in a Quest for greater knowledge and deeper understanding.

Begin your CERN Quest. Take Part!

Diversity has been an integral part of CERN's mission since its foundation and is an established value of the Organization. Employing a diverse workforce is central to our success.