Mechanical Engineer - AD horn and target (SY-STI-TCD-2025-169-GRAE)

Job Description

Your responsibilities

Are you a highly motivated Mechanical, Aerospace or Nuclear Engineer or an Applied physicist ready to join our team? This position comprises an exciting mix of theoretical and design studies with a strong focus on design for reliability.

The TCD (Targets, Collimators and Dumps) Section within the STI (Sources, Targets, and Interactions) group is responsible for all primary Beam-Intercepting Devices (BIDs) at CERN. Our involvement spans the entire life cycle of the devices, from their conceptual design to their production, installation, operation, and decommissioning.

The target for the Antiproton Decelerator (AD) is the primary component for antiproton production at CERN's AD facility. Antiprotons are produced by impinging a high-energy 26 GeV/c proton beam from the Proton Synchrotron (PS) onto the target. The current AD Target design, in operation since 2021, uses a 3-mm-diameter, 55-mm-long iridium rod (one of the densest, highest-Z materials available) which is encapsulated in carbon-based materials and is enclosed in a Ti Gr5 housing that provides both cooling and effective containment.

Each proton beam pulse deposits an extremely high energy density in the iridium core, causing a near-instantaneous temperature rise on the order of ~2000°C and generating pressure waves of several GPa within the material. Maintaining the target's integrity under such conditions is crucial for antiproton yield since any loss in material density would directly reduce antiproton production efficiency.

A comprehensive R&D program to identify an optimal target configuration, both in terms of geometry and materials, has been ongoing for several years. Notably, this program will now take advantage of the imminent dismantling of ex-operational AD-Targets and the use of novel intercepting materials, such as the tungsten alloy TFGR-W1.1TiC developed by KEK.

The magnetic horn for the AD-target is a crucial component to produce antiprotons as it enables focusing of antiprotons produced in the iridium target. Without the horn, the intensity of antiprotons is reduced by a factor of 50. The horn consists of a 7000-series aluminium alloy inner and outer conductor, through which a high current (up to 430 kA in 150 µs) is flowing, generating a toroidal magnetic field of up to 16 T between the conductors to focus the antiprotons.

The current horn design dates to the 1990s. The horn was operated at a current of 380 kA until the end of Run 2 (2018). With the start of Run 3 in 2022, the current was increased to 430 kA, significantly enhancing the transmission of anti-protons to the AD machine for experiments. However, this increase has led to multiple flashover events, caused by sparking at the contact point between the inner and outer conductors.

A consolidation program has been initiated to investigate the root causes of these flashovers. The program aims to design, produce, test and install new magnetic horns capable of operating reliably under higher peak current values. Additionally, the possibility of using an alternative conductor configuration and geometry is being explored.

In this role you will:

• Develop simulations for the AD-Target, considering past developments, the return of experience from ongoing Post-Irradiation Examination activities and the use of alternative intercepting materials.
• Contribute to the consolidation of the horn design by performing Finite-Element Analysis (FEA) simulations to assess the electro-magnetic and thermo-mechanical response.
• Collaborate closely with draughtsmen, physicists, and engineers to align technical specifications and preliminary design with physics requirements.
• Coordinate the design of the consolidated horns from the conceptual stage through the manufacturing of functional prototypes.
• Coordinate the manufacturing steps in collaboration with the technical support groups.
• Define and coordinate instrumented test runs for the prototypes.

More information here .

Your profile

Skills:

• Strong technical understanding of mechanical engineering principles, with expertise in mechanics of materials, heat transfer, and material science.
• Experience in relevant FEA software tools, such as ANSYS Workbench. Knowledge of LS-DYNA for thermomechanical simulations is considered a strong plus.
• Experience in the redaction of technical documents (engineering reports, scientific publications, and procurement specifications).
• Effective communication and interpersonal skills to facilitate collaboration.
• Proactive problem-solving mindset with the ability to defend ideas using technical arguments.
• Autonomy in handling specific technical tasks within a team context.
• Strong organisational skills to manage own and other people's work.
• Hands-on approach and readiness to support technical activities.
• Spoken and written English, with a commitment to learn French.

Eligibility criteria:

• You are a national of a CERN Member or Associate Member State .
• By the application deadline, you have a maximum of two years of professional experience since graduation in Mechanical, Aerospace, Nuclear Engineer (or a related field) and your highest educational qualification is either a Bachelor's or Master's degree.
• You have never had a CERN fellow or graduate contract before.
• Applicants without University degree are not eligible.
• Applicants with a PhD are not eligible.

Additional Information

Job closing date: 24.09.2025 at 23:59 CEST.

Contract duration: 24 months, with a possible extension up to 36 months maximum.

Working hours: 40 hours per week

Target start date: 01-November-2025

This position involves:

• Work in Radiation Areas.
• Interventions in underground installations.
• A valid driving licence.
• Exposure to ionising radiation and classified as category A.
• 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 reference: SY-STI-TCD-2025-169-GRAE

Field of work: Mechanical Engineering

What we offer

• A monthly stipend ranging between 5196  and 5716  Swiss Francs (net of tax).
• Coverage by CERN's comprehensive health scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
• Depending on your individual circumstances: installation grant; family, child and infant allowances; payment of travel expenses at the beginning and end of contract.
• 30 days of paid leave per year.
• On-the-job and formal training at CERN as well as in-house language courses for English and/or French.

About us

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 http://home.cern.

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.