Your responsibilities

The Radio Frequency Group (RF) within CERN's Accelerator Systems Department (SY) is seeking an Applied Physicist/Engineer to join the Superconducting Radio Frequency Cavity Technology section (SRF). You will be part of a small, dedicated team responsible for developing and implementing a new class of non-mechanical tuners for superconducting RF cavities, investigating both standalone cavity and integrated cryomodule solutions.

This is a challenging, multi-disciplinary project where you will take an active role in defining and assessing the integration and performance of a novel RF cavity tuning application. You'll be at the forefront of the development of a new frequency-tuning approach for SRF cavities, working on systems for both discrete RF frequency switching and continuous frequency modulation. Ultimately, your work will be applicable to CERN's Large Hadron Collider (LHC), the proposed Future Circular Collider (FCC), and the EU-funded Innovate for Sustainable Accelerating Systems (iSAS) program.

Your activities will include:

• Prototype Development: work on developing high-performance prototypes, including a tuning system for discrete frequency switching of 400 MHz SRF cavities within an existing LHC cryomodule, and a continuous tuning system for an 800 MHz multi-cell cavity for the FCC.
• Tuner Design & Simulation: perform advanced multi-physics simulations to contribute to the tuner's design and its integration into the broader accelerator system; key design considerations will include RF performance, thermal load, and power handling capabilities.
• Experimental Validation: perform validation and performance assessment of existing prototype tuners, acquiring hands-on measurement and data analysis expertise.
• Overcoming Technical Constraints: address constraints related to reliability, mechanical compactness, and thermal management throughout the design and development process.

This role provides a broad, multidisciplinary environment with a focused team for the development of an accelerator system component, offering significant opportunities for professional growth over a diverse experience base.

Your profile

Skills:

• RF or microwave engineering/physics;
• Multi-physics simulations;
• Design/construction of experimental setups;
• Software development (Python);
• 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 RF engineering, superconducting RF (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-2025-150-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.