Postdoctoral researcher in Accelerator Physics

The European Spallation Source (ESS) is one of the largest science and technology infrastructure projects being built today. Our goal is to become the brightest source of neutrons for science and technology and be operational by the end of this decade. A state-of-the-art suite of neutron scattering instruments will be made available to address a wide range of scientific fields in fundamental and materials science. Powered by the world’s most advanced linear proton accelerator, ESS will enable cutting-edge research in materials science, energy, health, and the environment for decades to come.

Join us in shaping the future of science – from the ground up.

About the role:

ESS is excited to begin the search for an engaged and motivated accelerator physics postdoctoral student to work within our beam physics group. In this role, you will conduct a feasibility study into the viability of a system for generating proton pulses in the range of 10-100µs using the existing ESS proton accelerator and neutron production infrastructure.

This position will place you at the heart of a high‑impact study to create “the ultimate neutron source” – with real consequences for the future operational flexibility of ESS. You will have the freedom to explore new ideas, the support of an experienced beam physics team, and access to world‑class accelerator infrastructure whilst simultaneously contributing directly to the evolution of neutron science.

If you are excited by challenging assumptions, pushing accelerator performance, and shaping what ESS can do next, then this role is for you. This role is a fixed-term position for a period of 2 years and is fully funded by ESS. The role is primarily “on-site” and will be based at the brand-new ESS campus in Lund, Sweden.

Day-to-day, you will:

• Carry out beam dynamics simulations to assess the feasibility of producing 10–100 µs neutron pulses using the existing ESS accelerator infrastructure.
• Develop and optimise lattice designs and beam parameters, with a focus on high‑intensity and space‑charge‑dominated beams.
• Perform multi‑particle tracking studies and analyse beam losses, collective effects, and operational constraints.
• Use and develop accelerator modelling tools (e.g. MadX, (py)ORBIT, XSuite, Python‑based workflows).
• Interpret results in close collaboration with beam physics, accelerator, and neutron science colleagues.
• Document and communicate results through clear technical notes, reports, and presentations.
• Contribute to scientific publications and conference contributions.

About you:

Our ideal candidate will hold a PhD in physics or a closely related field by the start of employment and will already be comfortable operating at the frontier of accelerator physics research.

You must bring:

• Proven experience in accelerator physics, with a strong preference for beam dynamics of high‑intensity and space‑charge‑dominated beams.
• A demonstrated ability to conduct independent, high‑impact research, evidenced by publications in peer‑reviewed journals and/or presentations at leading accelerator conferences.
• A solid foundation in particle tracking and beam optics, with hands‑on experience in relevant simulation tools considered a strong advantage.

You also need a strong grasp of the core principles that make accelerators work. This includes:

• The dynamics of charged particle beams.
• Basic accelerator technologies and their operational constraints.
• Lattice design and optics optimisation.
• Multi‑particle and collective effects, particularly in high‑intensity regimes.

Skills that will make you stand out:

• Programming and data analysis, e.g. Python, C or similar
• Hands‑on use of accelerator and lattice design tools such as MadX, (py)ORBIT, XSuite, or equivalent codes
• Simulation of high‑intensity, space‑charge‑dominated beams, including benchmarking and interpretation of results.

To apply:

A career at ESS gives you the opportunity to contribute to the future discoveries within neutron science at a stunning, brand-new workplace filled with innovative minds and brilliant people from across the globe. We offer market competitive, individualised compensation which is differentiated according to role, responsibilities, individual skills, abilities and achievements as well as monthly pension contributions on top of your salary.

If you see yourself in what we’re looking for, please provide your CV and motivation letter in English by clicking on “apply” and following the instructions. Please be aware that we can only accept direct applications made via the ESS website. Apply as soon as you can and quote the job reference number ESD-73807 in your application.

This role requires additional background screening processes and health and safety checks, which will be performed during the recruitment process.

For more information regarding the ESS recruitment process, please contact Talent Acquisition Specialist Daniel Nordin Baker on daniel.nordin@ess.eu. For trade union information, please contact Unionen representative Nerusha Naicker on Nerusha.Naicker@ess.eu or SACO/Swedish Association of Graduate Engineers representative Marc Kickulies at marc.kickulies@ess.eu

We look forward to receiving your application soon.