Accelerator Physicist (BE-RF-BR-2019-89-LD)

  • Geneva, Switzerland
  • Contract

Company Description

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

Job Description


Are you interested in working in the largest accelerator complex in the world?

Would you like to work at powerful synchrotrons in the injector chain of the Large Hadron Collider (LHC)?

Come and work alongside top scientists and engineers to exploit and upgrade CERN’s accelorators. We are looking for an Accelerator Physicist for Radio Frequency (RF) Operation and Beam Studies to help operate the RF systems of the Super Proton Synchrotron (SPS) accelerator and to play a key role in improving beam and RF system performance of the SPS, its injectors and the LHC. This could be the next exciting challenge in your career… take part!

You will join:

  • The Beams Department (BE), which hosts the Groups responsible for beam generation, acceleration, diagnostics, controls and performance optimisation. (
  • The Radio-Frequency (BE-RF) Group ( of the BE Department, responsible for the operation of all RF systems to accelerate and control the particle beams in all CERN synchrotrons and linear accelerators, including projects for future accelerators and upgrades to the existing installations.
  • The Beams and RF Studies (BE-RF-BR) Section within the RF Group takes care of the interactions of various beams (protons, anti-protons and heavy ions) with RF systems and their environment in all CERN synchrotrons. The BR Section is strongly involved in performance improvements and upgrades of existing accelerators as well as in the design of RF systems for present and future CERN accelerators. (


As Accelerator Physicist for Radio Frequency Operation and Beam Studies in the BR Section, you will be part of the team running CERN's SPS accelerator, its injector (PS) and the LHC.

In particular, you will contribute to the operation of the RF beam control and feedback systems. A large part of your work on existing synchrotrons will be the study of performance limitations related to the RF systems and longitudinal beam dynamics (beam loading, stability, RF manipulations and others) and the means to push to higher beam intensities after the upgrades performed during the current long shutdown (LS2). These studies will consist of participation in beam measurements during beam commissioning and Machine Development (MD) sessions, followed by data analysis as well as analytical calculations and numerical simulations. This work will also involve further development of the existing longitudinal beam observation system, the follow-up of RF upgrades, as well as contributions to CERN projects, notably High Luminosity (HL)-LHC and the Future Circular Collider (FCC).

To summarise, your main activity will be to participate in the beam commissioning of the SPS towards HL-LHC intensity and in the operational issues related to the RF beam control system. Additionally, you will participate in beam studies and propose improvements.

After an initial learning period, you will:

  • Set-up operational beams as well as beams with special parameters for various MD studies.
  • Participate in beam commissioning (up to High-Luminosity LHC intensities) after the long shutdown 2 (LS2).
  • Perform theoretical studies to analyse the longitudinal beam behaviour in the SPS and LHC.
  • Suggest possible improvements to the RF systems and measures to increase beam quality and stability.
  • Participate in MDs, notably related to the intensity increase of the LHC beams.
  • Maintain longitudinal beam observation systems; suggest and implement improvements.
  • Contribute to the upgrade of the RF beam control and feedback systems.
  • Work closely with accelerator physicists, operations teams, RF power and hardware engineers to achieve the aforementioned tasks.
  • Participate in the standby service for the low-level RF systems in SPS and LHC.


Master's degree or PhD or equivalent relevant experience in the field of Electrical Engineering or Physics, or a related field.


  • Demonstrated experience of working in the RF domain.
  • Proven experience in longitudinal beam dynamics in circular particle accelerators.
  • An initial experience in using beam observation systems.
  • Operational experience with RF beam control systems would be an advantage.
  • Experience in beam studies, data acquisition and analysis would be an advantage.

Technical competencies:

  • Analysis and optimization of accelerator performance.
  • Knowledge of longitudinal single-particle dynamics.
  • Knowledge and application of collective effects.
  • Knowledge of code(s) for beam dynamics simulations.
  • Initial knowledge of RF beam diagnostics.

Behavioural competencies:

  • Achieving results: having a structured and organised approach towards work; being able to set priorities and plan tasks with results in mind.
  • Demonstrating flexibility: demonstrating openness to new ideas and situations; being able to deal with ambiguous or unpredictable situations; adapting quickly and resourcefully to shifting priorities and requirements.
  • Communicating effectively: ensuring that information, procedures and decisions are appropriately documented.
  • Learning and sharing knowledge: keeping up-to-date with developments in own field of expertise and readily absorbing new information; proposing ways to improve or streamline existing procedures, processes and methodologies.

Language skills:

  • Spoken and written English: ability to draw-up technical specifications and scientific reports and to make oral presentations. 
  • Spoken and written French would be an asset.

Additional Information

Eligibility and closing date:

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. We welcome applications from all Member States and Associate Member States.

This vacancy will be filled as soon as possible, and applications should normally reach us no later than 19/09/2019.

Employment Conditions

Contract type: Limited duration contract (5 years). Subject to certain conditions, holders of limited-duration contracts may apply for an indefinite position.

These functions require:

  • Participation in a regular stand-by duty, including nights, Sundays and official holidays.
  • Work in radiation areas.
  • Interventions in underground installations.
  • A valid driving licence.

Job grade: 6-7

Job reference: BE-RF-BR-2019-89-LD

Benchmark Job Title: Applied Physicist

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