Detector Simulation Physicist

What you'll do

In this role, you will develop and improve GPU-accelerated Monte Carlo detector simulation software within the Geant4 team, with a particular focus on optical-photon transport. You will contribute to software design and implementation, physics validation against established CPU simulations, performance optimisation, and integration into experimental software frameworks.

Your responsibilities

Design, develop, and integrate GPU algorithms for optical photon simulation within a Monte Carlo particle-transport framework.
Compare and validate GPU simulation results against established CPU implementations.
Develop unit, regression, and physics-validation tests.
Profile applications, identify performance bottlenecks, and optimise computational performance.
Collaborate with software teams from the Large Hadron Collider experiments to integrate GPU-enabled particle transport into their simulation frameworks.
Engage with the international Geant4 collaboration and its user community, particularly in the area of optical photon simulation.
Contribute to the documentation, maintenance, and long-term quality of the developed software.

Still here? Let's make a quick check about

Your profile

Experience in developing scientific or physics-simulation software, preferably using modern C++.
Experience with GPU programming or software development for heterogeneous computing architectures.
Experience with software testing, numerical validation, performance profiling, or optimisation.
Knowledge of Monte Carlo methods or experience with particle-transport simulation would be an advantage, particularly in the area of optical photon transport.
Experience contributing to collaborative software projects or working within an international scientific environment would be an advantage.
Your studies focused on Physics, Computer Science, or a related.

Your skills

Programming languages and technologies: modern C++, CUDA, Python.
GPU programming, heterogeneous computing, and performance optimisation.
Git and collaborative software development.
Unit testing, regression testing, and numerical validation.
Experience with Monte Carlo particle-transport codes such as Geant4 would be considered an advantage.
Debugging and profiling tools such as gdb, Compute Sanitiser, perf, Nsight Systems, or Nsight Compute would be considered an advantage.
Spoken and written English, with a commitment to learn French.

Ideal start date: 01/01/2027

Contract duration (in months): 24

Job flexibility: Hybrid

Employment conditions

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

Global Benefits at CERN

A monthly net stipend of either 6372 or 7004 Swiss Francs per month depending on your degree and years of post-graduation 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 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, Lithuanian, Latvian, Cypriot, Croatian and Turkish nationals, 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!

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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.