JOB DESCRIPTION

CERN Position: Applied Physicist for Particle Detectors (EP-AID-DT-2025-181-LD)

Location: Geneva, ch

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.

Job Description:

Introduction

Are you an applied physicist with expertise in particle detectors? Do you want to help build ALICE’s next-generation silicon vertex detector and drive the R&D for the experiment’s future evolution? This could be your opportunity. Take part!

As an Applied Physicist, you will use and develop physics models and conduct research in a multidisciplinary environment to develop new technologies and solve engineering challenges in support of CERN’s research programme.

ALICE (A Large Ion Collider Experiment) is one of the four large experiments at the LHC and a general-purpose heavy-ion detector designed to study strongly interacting matter using nucleus-nucleus, proton-nucleus and proton-proton collisions. ALICE is upgrading its Inner Tracking System with a novel ultra-light vertex detector (ITS3) based on wafer-scale monolithic active pixel sensors (MAPS) bent around the beam pipe. After the completion of its development, the detector will be assembled, commissioned and installed during LS3 (2026-2029) for operation in Run 4 (2030-2033). In parallel, ALICE has proposed an all-silicon experimental apparatus for Run 5 (2036-2040), ALICE 3, featuring a retractable silicon vertex detector installed in secondary vacuum inside the beam pipe.

The successful candidate will join the Detector Technologies (EP-AID-DT) section of the ALICE Detector and Systems (EP-AID) group, with responsibilities in the ITS3 project that include:

• Characterisation and integration of MAPS.
• Development of hardware and software for the test setup for full-size pixel-sensor prototypes (MOSAIX).
• Detector construction and commissioning.

The section is also actively developing novel detector technologies, including ultra-light, wafer-scale curved monolithic pixel sensors integrated inside the beam pipe on a retractable support structure.

Functions

As an Applied Physicist in EP-AID-DT, you will contribute to the finalisation of the ITS3 silicon pixel sensor development and the ITS3 detector construction, commissioning and operation, as well as to new silicon-pixel systems for future upgrades.

Your functions will include:

• Prototype characterisation: plan and execute laboratory and beam-test campaigns; develop/operate test benches and DAQ; perform calibration and data analysis (noise, charge collection, efficiency, radiation tolerance, mechanical curvature).
• Sensor and test-system development: contribute to the design, prototyping and qualification of new sensor components and test systems (e.g. front-end/readout, interconnects, flex, cooling, mechanics; firmware/software for test stands such as MOSAIX).
• System integration and installation: prepare integration procedures; coordinate installation and services (beam pipe interfaces, DAQ, controls, cooling, vacuum) with ALICE subsystems.
• Commissioning and operation: define commissioning strategies; bring subsystems to readiness; develop calibration, alignment and online monitoring; ensure reliable operation and performance follow-up during data taking.
• R&D for future upgrades (ALICE 3): Specify requirements, evaluate concepts (including retractable in-vacuum curved MAPS), prototype and benchmark novel solutions.
• Project coordination and reporting: chair technical meetings and reviews; plan schedules and deliverables; track risks and mitigations; report progress to EP-AID management and collaboration boards.
• Supervision and knowledge transfer: supervise and mentor students, fellows and post-docs; provide technical coaching and training; produce high-quality documentation.

Qualifications:

PhD or equivalent relevant experience in the field of detector systems for particle physics or a related field.

Experience:

• Postdoctoral experience in the development and construction of particle physics detectors.
• Hands-on expertise in the assembly, integration and testing of detector systems.
• Experience with detector hardware and software, including Detector Control Systems (DCS), Data Acquisition (DAQ) and data analysis.
• Experience with silicon pixel detector technologies, especially MAPS, would be an advantage.

Technical competencies:

• Simulation, design and development of (part of) particle accelerators.
• Analysis and optimization of detector performance: calibration, alignment, efficiency/occupancy studies, material budget; data analysis with C++/Python/ROOT.
• Assembly and integration of detectors: qA/QC, integration with services and interfaces.
• Operation of experiments: and systems – DAQ/DCS operation, online monitoring, troubleshooting, run readiness and performance follow-up.
• Knowledge and application of solid-state based particle detection technologies: silicon pixel sensors (MAPS and/or hybrid), interconnects and modules, radiation effects and qualification.

Behavioural competencies:

• Achieving Results: driving work / projects along and seeing them through to their conclusion.
• Demonstrating Flexibility: actively participating in the implementation of new processes and technologies.
• Demonstrating Accountability: working conscientiously and reliably; delivering on promises.
• Working in Teams: working well in groups and readily fitting into a team; participating fully and taking an active role in team activities.

Language skills:

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

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 05.10.2025 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

This position involves:

• Work in Radiation Areas.
• Interventions in underground installations.
• Work during nights, Sundays and official holidays, when required by the needs of the Organization.
• Stand-by duty, when required by the needs of the Organization.

Job grade: 6-7

Job reference: EP-AID-DT-2025-181-LD

Benchmark Job Title: Applied Physicist

Level of Education: Master Degree

Work Hours: 8

Experience in Months: 24

Level of Education: Master Degree

Work Hours: 8

Experience in Months: 24

Organization: European Organization for Nuclear Research (CERN)