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. 

Introduction

Within the Beam department (BE) and the Accelerator and Beam Physics group (ABP), join the Hadron Sources and Linacs section (HSL) at CERN as a lead applied physicist overseeing the Linac3 ion source, a role bringing together multiple physics domains coupled with beam dynamics, including high voltages, high magnetic fields, plasma heating with microwaves, the delivery of gases and vapours into vacuum systems as well as x-ray generation and shielding. You will ensure the high-performance delivery of heavy ion beams, driving both daily operations and long-term technical development of the system providing particle beams for one of the world's most unique accelerator complexes, serving fixed-target users and the LHC.

Functions

• Coordinate and participate in the Linac3 ion source assembly and maintenance activities during technical stops and shutdowns to ensure preparation for high-availability operation.
• As the expert in-charge, commission and operate the source, tuning it precisely to optimise performance and stability for Linac3 and the downstream injectors, ensuring compliance with beam quality specifications for CERN ion runs and various tests.
• Design and implement technical solutions to test and validate the production of different ion species requested for future physics programmes.
• Be part of the machine expert team, contributing to broader beam operations and participating in the on-call service rotation to ensure 24/7 injector reliable operation.
• Supervise and mentor a multidisciplinary team including physicists, engineers, technicians and students.
• Conduct advanced beam measurements and data analysis to characterise Linac3 performance and identify areas for optimisation.
• Contribute to the design studies and execution of upgrades for the CERN ion injector complex, focusing on source technology and low energy beam transport (LEBT).
• Contribute to other BE-ABP-HSL activities through beam dynamics design, simulations and commissioning for present and future hadron linacs and sources under the section’s responsibility.

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

Experience:

• Demonstrated experience of work in the design and/or operation of particle sources for accelerators or in a related scientific field.
• Hands-on experience with particle sources or other similar scientific equipment, including the use of different materials for equipment design and handling for equipment use in vacuum.
• Hands-on experience with high-voltage equipment or microwave generators.
• Experience with multi-particle simulation codes for sources and linacs. Experience with one or more the following codes would be an asset: iBSIM, SIMION, TRAVEL, TRACEWIN, PARMTEQ, RF-TRACK.
• Experience of experimental techniques and analysis of beam measurements data.

Technical competencies:

• Simulation, design and development of beam sources.
• Operation of accelerators.
• Analysis and optimisation of accelerator performance.
• Configuration and implementation of industrial data-acquisition, monitoring and control systems.
• Organisation, planning and control.

Behavioural competencies:

• Demonstrating Accountability: taking responsibility for own actions and decisions.
• Solving Problems: addressing complex problems by breaking them down into manageable components.
• Communicating Effectively: delivering presentations in a structured and clear way; adjusting style and content to the audience; responding calmly and confidently to questions.
• Leading with Strength and Credibility: making timely decisions that balance systematic analysis with decisiveness; dealing with difficulties in a timely manner.

Language skills:

Spoken and written English, with a commitment to learn French.

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 16.07.2026 at 23:59 CEST.

Employment Conditions

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

Working Hours: 40 hours per week

Job Flexibility: Hybrid

This position involves:

• Work in Radiation Areas.
• Interventions in underground installations.
• A valid driving licence.
• Exposure to lead.
• 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.

Job grade: 6-7

Job reference: BE-ABP-HSL-2026-133-LD

Field of work: Applied Physics

Benchmark Job Title: Applied Physicist

Global Benefits

• A competitive salary (tax free), increasing in line with your years of relevant experience.
• 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, removal, travel expenses) depending on your individual circumstances.
• Possibility to extend your contract up to 8 years + eligibility for indefinite contract tenure.

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!

More information about us, here: careers.cern