Your responsibilities

Join the Beams and Radio Frequency Studies (BR) Section of the Radio Frequency (RF) Group as an Accelerator Physicist!

Machine development studies in the LHC, including the RF commissioning during the "heat run" are a major priority, and a mandatory step to prepare the operation with the high-efficiency klystrons at HL-LHC intensities. This higher intensity requires the operation of the RF system in much more constrained regime, only accessible with evolved tools to run at optimum detuning and loaded quality factor to reduce the RF power. The execution and analysis of the MDs in 2026 will provide essential input to prepare the tools and models in LS3 for an efficient recommissioning with the high-efficiency klystrons.

You will drive the execution and analysis of the beam measurements as well as test the full-detuning scheme in the SPS and the LHC before the end of Run 3.

Your responsibilities will include:

• Carrying out beam measurements;
• Developing automated software tools to automatically optimise detuning and loaded quality factor in 2026;
• Based on the result of the beam studies, contributing to the development of new algorithms and their embedding into the control infrastructure, including RF infrastructure during LS3;
• Developing the software tools to evaluate the ultimate performance of high-efficiency klystrons including cavity and low-level RF modelling for RF capture, acceleration, noise blow-up and storage of HL-LHC beams;
• Performing beam dynamics simulations on intra-beam scattering, RF noise and intensity effects.

Your profile

Skills:

• Experience in longitudinal beam dynamics and intensity effects;
• Experience with beam measurements and hardware calibration;
• Experience with beam dynamics simulations;
• Experience in control loop modelling;
• Conceptual knowledge of RF systems, including amplifiers, cavities, and low-level RF systems;
• Candidates with a PhD in Physics, specifically Accelerator Physics, will be prioritised;
• 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 Accelerator Physics (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: 21.08.2025 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-November-2025

Job reference: SY-RF-BR-2025-128-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!

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