Applied Physicist in Gas Detectors and Systems

What you'll do

Particle detectors operating at CERN’s Large Hadron Collider experiments require highly specific, precise, and stable gas mixtures, provided by dedicated and complex gas systems often operating in gas recirculation. Correct and stable mixture composition is a fundamental requirement for the long-term, continuous operation of all detectors.

You will join the Gas Systems team in the EP-DT-GD, responsible for the maintenance, operation and development of the gas systems for particle detectors. The team is responsible for approximately 40 gas systems delivering the required mixtures to the particle detectors across all CERN experiments.

Under certain conditions, particle detectors in the LHC experiments use greenhouse gases (GHGs). CERN is strongly committed to reducing GHG emissions from the operation of particle detectors. The Gas Systems team has identified four strategies to optimise GHG usage: gas recirculation, gas recuperation, new environmentally friendly gases and gas abatement.

Your responsibilities

Active involvement in the operation, maintenance, and technical upgrades of gas systems for one of the LHC experiments, ensuring continuous and stable operation.
Participation in the "piquet" (stand-by duty) service, providing technical support and rapid intervention to ensure 24/7 operational reliability of gas systems during LHC runs.
Contribution to R&D studies aimed at identifying replacements for currently used greenhouse gases (GHGs), such as R134a and SF6.
Contribution to and responsibility for the operation of test setups in the laboratory and at CERN facilities, where the high-radiation background expected during the High-Luminosity LHC phase can be simulated.
Validation of the compatibility of new eco-friendly gases with components used in gas system construction, ensuring no impact on detector performance.
You will learn about gaseous detectors, gas systems, gas recirculation, and gas recuperation.

Still here? Let's make a quick check about

Your profile

Experience in operating different types of gaseous detectors.
Experience in the design, operation, or maintenance of gas systems.
Practical knowledge of industrial instrumentation and sensors.
Experience in operating gaseous detectors in high-radiation environments and with eco-gases.
Ability to perform technical interventions in experimental areas.
Your studies focused on Physics or Engineering.

Your skills

Understanding of gaseous particle detector operation and radiation effects.
Operation of gaseous detectors with eco-gas mixtures.
Knowledge of gas distribution systems.
Familiarity with gas analysis techniques (gas chromatography) and leak detection methods.
Proactive approach to identifying potential system weaknesses before they lead to operational downtime.
Ability and willingness to work in a variety of environments, from high-tech laboratories to underground experimental caverns, and to adapt to changing priorities during LHC technical stops and data-taking periods.
Spoken and written English or French, with a commitment to learn the basics of the other language.

Ideal start date: 01/10/2026

Contract duration (in months): 24

Job flexibility: Fully Onsite

Team supervision

Medical hazard

Exposure to ionising radiation and classified as category A.
Exposure to risk of falling from heights during scaffolding assembly and dismantling operations.
Exposure to electromagnetic fields under certain exposure conditions.

Given the occupational health risks associated with this position, the selected candidate must obtain medical clearance before a contract offer is confirmed.

Employment conditions

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

Global Benefits at CERN

A monthly net stipend between 6372-7004 Swiss Francs per month depending on your degree.
30 days of paid leave per year plus 2 weeks annual closure.
Coverage by CERN’s comprehensive health insurance scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
Family, child and infant monthly allowances depending on your individual circumstances.
A relocation package (installation grant and travel expenses) depending on your individual circumstances.
Possibility to extend your contract up to 36 months.
On-the-job and formal training including language classes.

Let's get you ready

Be sure to meet the eligibility criteria

You are a national of a CERN Member State or Associate Member State. Currently, we cannot consider applications from Pakistani and Lithuanian nationals for positions with a 2026 start date, as the ceiling defined under Article II.5 of the Associate Membership Agreement has been reached.
By the application deadline, you have a master’s degree with 2 to 6 years of professional experience since graduation or a PhD with a maximum of 3 years of professional experience since graduation. You are not eligible with only a bachelor’s degree.
You have never had a CERN fellow or graduate contract before.
Please pay attention to the additional criteria and requirements for this specific position and mentioned above.

You will need these documents to complete your application

Your CV (English or French)
A copy of your most relevant diploma or a certificate of achievement from your school (if you don't yet have your paper diploma)
Any document you consider relevant to your application

Your CERNDepartment

The EP department conducts research in experimental particle physics in close collaboration with and supporting the wider scientific community working at CERN. This includes designing and operating experiments, developing and constructing detectors, acquiring and analysing physics data.

Overview of CERN

Discover a world where the impossible is made possible!

At CERN, the European Organization for Nuclear Research, we are pushing the frontiers of science and technology. Our groundbreaking work brings together not only physicists but also a diverse range of professionals from engineering, technical, scientific, and administrative fields. Together, we foster an environment where innovation and collaboration thrive.

Every day, we face exciting new challenges and opportunities to contribute to cutting-edge research that shapes our understanding of the universe. We meet these challenges through the diverse perspectives within our teams, ensuring every contribution is valued and driving our shared sense of inclusion and purpose. Diversity is a core value of CERN since its foundation, and it remains central to our mission and continued success.

If you are ready to be part of a dynamic, inclusive community pushing the boundaries of knowledge, CERN is the place where your curiosity and skills can thrive. Be part of our mission to uncover what lies at the heart of the universe! TAKE PART!

Ready To apply?

Be prepared with our resources and tips

All good?

Apply now Allow 15 minutes to complete your online application

Still have a doubt ? Here are the most frequently asked questions

What should I expect during my first week at CERN?

Your onboarding at CERN includes a comprehensive induction programme, which starts with an official welcome session at the beginning of each month. In addition, you will receive important information both before and after your arrival to ensure a smooth transition into your new role. This process is designed to help you get acquainted with CERN’s environment, your team, and the tools and systems you’ll be using.
How big would the team be?

The size of the team you'll be working with at CERN depends on the specific role and department. Some teams are small and highly specialized, while others are larger and more interdisciplinary. During the interview process, you'll have the opportunity to learn more about the team structure for the position you are applying for.
What is the working language at CERN?

The working languages at CERN are English and French. However, it is not always mandatory to speak both languages to work at CERN. We offer language training to help you acquiring the other language.
What support does CERN provide for relocation?

CERN does not offer direct assistance with relocation. However, depending on your role and specific criteria, you may be eligible for certain benefits such as an installation allowance and coverage of travel expenses to join CERN. These benefits are designed to help ease the transition when relocating to the Geneva area. For more information, please consult the “Salary, Benefits and Support“ page.
Do I need a visa to work at CERN?

Whether you need a visa to work at CERN depends on your nationality and the duration of your stay. CERN assists with the necessary visa and work permit processes for its employees and visitors. The specific requirements will be communicated to you during the recruitment process.
What would my salary be?

Salaries at CERN are determined by a structured scale. Salaries are based on your role, qualifications, and experience, and are not subject to negotiation. Specific details will be provided as your application progresses. For more information, please refer to the dedicated page.