Applied physicist for vacuum analysis and modelling (TE-VSC-VSM-2019-21-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 an applied physicist or engineer experienced in numerical modelling of vacuum systems and the operation of particle accelerators? CERN, take part!

The Vacuum Studies and Measurements (VSM) section is responsible for the study of vacuum system performance for the present and future accelerators including the high-luminosity of the Large Hadron Collider (LHC). It also provides the analysis and simulations of pressure and heat load profiles in relation to beam-induced effects such as synchrotron radiation, electron cloud, ion-induced losses, and their detrimental effects on the beam quality and lifetime.

The input data for the simulations are obtained by dedicated measurements and the elaboration of signals that are extracted from a database of thousands of vacuum gauges, pumps, and temperature sensors installed in CERN’s accelerators.

Simulations of the pressure and molecular density profiles along the various vacuum components are obtained using numerical codes such as PyVASCO, Molflow+ and SYNRAD+, Comsol, and LTSpice.

Support to experiments and beam monitoring - in terms of modelling molecular density and synchrotron light distribution near the detection points - is also one of the activities of the section. 


As an Applied Physicist in this section, you will play a key role in the:

  • Design, development, support and application of Monte Carlo simulation codes (Molflow+ and SYNRAD+) and their interface with the machine layout database as well as the development of software tools for extracting data from the machine database.
  • Contribution of data analysis studies aimed at simulating molecular density in the existing machines via numerical codes and compare the results to data extracted from the machine database.
  • Liaison with external institutions and provide support to the experiments in terms of data modelling: the pressure and molecular density near the interaction points, with the aim of minimising the beam-gas scattering background in the detectors.
  • Performance of vacuum measurements and analysis, in particular with synchrotron light and electrons to provide verification and input to simulation codes.
  • Writing of technical reports and scientific publications and present results at internal meetings and conferences.
  • Supervising of PhD students and Fellows involved in studies related to the use of numerical codes for vacuum simulation.


PhD or equivalent relevant experience in the field of applied physics, or a related field.


  • Proven experience in computer programming with modern languages (eg C, C++, Python) and writing numerical simulation codes.
  • Demonstrated experience in the vacuum design of accelerator equipment assisted by Monte Carlo simulations.
  • Previous experience in accessing large databases and extracting data for comparison to simulations and data analysis.
  • Familiarity with modern ultra-high vacuum technology hardware and practices would be an asset.
  • Previous experience with vacuum measurements of synchrotron radiation and electron induced desorption yields would be an asset.

Technical competencies:

  • Design and simulation of UHV systems.
  • Pressure measurement and residual gas analysis in UHV systems.
  • Development of application software such as Monte Carlo based code.
  • Knowledge of programming techniques and languages (in particular Java, C++ and Python).
  • Simulation, design, and development of particle accelerators, such as beam pipes or cryogenic vacuum.
  • Analysis and interpretation of experimental data.

Behavioural competencies:

  • Achieving results: having a structured and organised approach towards work; being able to set priorities and plan tasks with results in mind; taking appropriate corrective actions and adapting work / project plans if necessary.
  • Communicating effectively: delivering presentations in a structured and clear way; adjusting style and content to the audience; responding calmly and confidently to questions.
  • Learning and sharing knowledge: keeping up-to-date with developments in own field of expertise; and readily absorbing new information.
  • Working in teams: working well in groups and readily fitting into a team; and participating fully and taking an active role in team activities.
  • Managing self: taking initiative beyond regular tasks and making things happen; actively seeking feedback on own performance and taking steps to improve it; working well autonomously; and taking on activities and tasks without prompting.

Language skills:

  • Very good knowledge of English: ability to draw-up scientific reports and  making oral presentations. 
  • Basic knowledge of French or an undertaking to acquire it rapidly.

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 16.04.2019.

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.
  • Work during nights, Sundays and official holidays, when required by the needs of the Organization.

Job grade: 6-7

Job reference: TE-VSC-VSM-2019-21-LD

Benchmark Job Title: Applied Physicist

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