Postdoctoral Research Assistant in High-Energy Beam Dynamics

Applications are invited for a Postdoctoral Research Assistant at the John Adams Institute: High-Energy Beam Dynamics.

The post is available initially for fixed-term duration of 24 months with the possibility of 12 months extension.

The John Adams Institute for Accelerator Science, Oxford, is seeking a Postdoctoral Research Assistant to lead an investigation into high-intensity particle beam dynamics relevant for hadron collider synchrotrons at the high-energy frontier, such as the LHC and its High Luminosity upgrade (HL-LHC) at CERN. Studies carried out as part of the Oxford team are conducted in close collaboration with the CERN Accelerator and Beam Physics Group, and the postholder will have opportunities to engage on designing dedicated experiments at the LHC accelerator complex.

This research project addresses a key collider-design question: achieving beam stability with minimal impact on beam lifetime. Detrimental coherent beam instabilities, such as the slow head-tail or electron cloud instability, are typically mitigated with schemes involving Landau octupole magnets. Their nonlinear fields induce frequency spread, providing Landau damping but reducing dynamic aperture. This can lead to slow beam loss and reduced beam lifetime, reducing luminosity for physics experiments.

The HL-LHC is designed to deliver a tenfold increase of integrated luminosity, partly with beams of twice the number of particles per bunch. This ultra-high beam intensity demands special attention to mitigate stronger collective beam instabilities. The LHC beam stabilisation scheme relies critically on Landau octupole magnets. Operating the collider requires carefully balancing stability and lifetime reduction. Past experience has shown that, sometimes, maximum Landau octupole strengths were required to stabilise the beams. Dynamic aperture is also sensitive to magnetic field imperfections of the main magnets in the collider’s interaction regions. Bench-measured field quality of the new HL-LHC magnets is now available, and the associated potential lifetime deterioration must be assessed and mitigated.  This project aims to contribute to understanding the associated beam dynamics, propose mitigation strategies, and explore alternative ideas.

The successful candidate will develop innovative solutions to maximise lifetime while ensuring stability. The study will involve computational modelling of dynamic aperture and coherent instabilities, as well as designing and conducting experiments at the CERN accelerator complex, followed by data analysis. Outcomes support the HL-LHC Upgrade by identifying possible improvements in dynamic aperture, e.g. through optics modifications or magnet sorting. The project also explores alternative stabilisation schemes as relevant for future collider designs. The postholder will take a leading role, as appropriate, in publishing and presenting results. There will be opportunities to teach, including lecturing, small-group teaching, and tutoring of undergraduates and graduate students.

Applicants should hold, or be close to completing, a PhD/DPhil in accelerator physics, particle physics, or a closely related discipline. Experience and interest in accelerator technologies is essential. Applicants should have a proven track record of high-quality research at large-scale accelerator infrastructures and a solid background in synchrotron beam dynamics and its numerical modelling. They should be able to identify research objectives and subsequently conceive, plan, and independently execute activities to deadlines, communicating effectively both orally and in writing. The ability to find information, analyse complex data, and present this in accessible form is essential.  

The closing date for applications is 12 noon on Wednesday, 3 December 2025. Applications must be made online. You will be required to upload a CV and supporting statement as part of your online application.

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