Accelerator Physicist (Collective Effects)

Are you an Accelerator Physicist experienced in collective effects and interested in working in an exciting international environment at the forefront of modern science? Do you want to contribute to the study of the mechanisms responsible for transverse coherent beam instabilities in accelerators? Take part and join one of the teams that help to deliver unique high-energy particle beams used by physicists from all over the world to answer questions at the heart of particle physics! CERN, take part!

Job Reference: BE-ABP-HSC-2017-234-LD
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Accelerator Physicist (Collective Effects) in the Beams Department (BE), Accelerator and Beam Physics Group (ABP), Hadron Synchrotrons Coherent effects (HSC) Section.


As an Accelerator Physicist (Collective Effects) you will join:


  • The Beams (BE) Department which is at the heart of the CERN accelerator complex and hosts the groups responsible for the beam generation, acceleration, diagnostics, controls and performance optimization.
  • The Accelerators and Beam Physics (ABP) Group, responsible for beam performance from the source to the Large Hadron Collider (LHC) and carries out Research & Development (R&D) activities on the upgrade of the LHC, its injectors, and future colliders (CLIC and FCC).
  • The Hadron Synchrotron Coherent effects (HSC) Section which is responsible for studying coherent effects and their mitigation by developing theoretical models, simulation codes and by conducting experimental research. Coherent transverse instabilities induced by beam coupling impedance and space charge, beam-beam, electron cloud effects and their interplay can limit the beam intensity and brightness and therefore the performance of the present and future CERN accelerators. An accurate theoretical description, precise models, realistic simulations and thorough benchmarking with dedicated experiments are required in order to assess the present and future performance limitations and devise cures, mitigation measures and the corresponding operational scenarios. (



As an Accelerator Physicist (Collective Effects), you will contribute to the study of the collective effects in particle accelerators, in particular the mechanisms responsible for transverse coherent beam instabilities. You will also devise mitigation techniques to push further the performance of the existing and future CERN accelerators.


Specific tasks will include:


  • Participate in the identification and characterization of the remaining sources of impedance in the CERN Accelerator Complex.
  • Estimate the longitudinal and transverse impedances of new accelerator equipment.
  • Conduct bench measurements of the longitudinal and transverse impedances of accelerator components.
  • Benchmark the impedance models with beam-based measurements in the different CERN accelerators: conceive and conduct machine experiments and analyse the corresponding data.
  • Follow up machine performance limitations related to impedance and its effects, identify possible non-conformities and propose solutions.
  • Contribute to the design of low-impedance elements and conceive cures and/or mitigation techniques.
  • Characterize the electro-magnetic properties (vs. frequency) of some materials used in the CERN accelerators or proposed to be used in the future.
  • Contribute to the development and maintenance of the CERN accelerators impedance database.


Qualification required

Master's degree or PhD, or equivalent relevant experience in the fields of physics or engineering, or equivalent.


Experience and competencies

The experience required for this post is:


  • Demonstrated experience in a scientific environment preferably in beam dynamics and/or operation of particle accelerators.
  • Demonstrated ability to perform electromagnetic computations and simulations of beam coupling impedances in time and frequency domains.
  • Experience with experimental techniques and analysis of data from beam measurements.


The technical competencies required for this post are:


  • Impedance computation and simulation: ABCI, ANSYS HFSS, CST STUDIO (MAFIA), GdfidL, ECHO2D, ACE3P.
  • Knowledge of accelerator physics theory.
  • Beam dynamics simulation: knowledge of multi-particle simulation codes such as PyHEADTAIL.
  • Accelerator performance analysis & optimization.
  • Knowledge of collective effects.


The behavioural competencies required for this post are:


  • Achieving results: having a structured and organised approach towards work; being able to set priorities and plan tasks with results in mind; driving work/projects along and seeing them through to their conclusion.
  • Working in teams: gaining trust and collaboration from others; building and maintaining constructive and effective work relationships.
  • Learning and sharing knowledge: proposing ways to improve or streamline existing procedures, processes and methodologies; using knowledge sharing systems and technology.
  • Demonstrating flexibility: adapting quickly and resourcefully to shifting priorities and requirements.


The language competencies required are:


  • Spoken and written English: ability to understand and speak the other language in professional contexts.
  • Ability to draw-up technical specifications and/or scientific reports and to make oral presentations.
  • Knowledge of the French language or the willingness to acquire this rapidly would be an advantage.


Eligibility conditions

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 18.01.2018.


By applying here, you allow CERN to consider your application for any position it considers relevant with respect to your profile. Please ensure you update your profile regularly with any relevant information and that you inform the recruitment service if you wish your file to be removed from the database.


Note on Employment Conditions

We offer a limited-duration contract for a period of 5 years. Limited-duration contracts shall terminate by default on their date of expiry. Subject to certain conditions, holders of limited-duration contracts may apply for an indefinite position.


These functions require:


  • Work in radiation areas.
  • interventions in underground installations.
  • Stand-by duty, when required by the needs of the Organization.
  • Work during nights, Sundays and official holidays, when required by the needs of the Organization.


Read more about employment conditions


Benchmark Job Title
Applied Physicist
Professional Category:
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Career Level
Grade 6 or 7
Number of Posts
Duration: 5 year(s)

Application is closed for this job.