Long scale plasmas for AWAKE proton driven plasma acceleration experiment

A fully funded-PhD studentship position has become available in the Blackett Laboratory at Imperial College to work on the AWAKE project at CERN.

Plasma-based accelerators can sustain acceleration gradients orders of magnitude higher than conventional devices, thereby enabling more compact accelerators to be developed. Plasma wakefield acceleration (PWFA) driven by high energy proton beams is one of the most promising schemes for electron acceleration to 100 GeV or TeV energies, as required for particle physics applications and next-generation colliders [1].

This is being investigated by the AWAKE project at CERN, which uses 450 MeV proton beams from the Super Proton Synchrotron (SPS) to drive a wakefield in a 10 m plasma cell. This experiment has so far demonstrated wakefield growth [2] and electron acceleration by 2 GeV [3].

In order to reach the higher energies needed for a particle collider, a discharge plasma source (DPS) that can be scaled up to ~100 m is being developed in collaboration between CERN, Imperial College and IST, Lisbon. The versatility of the DPS has been demonstrated using a 10 m source at CERN, including its scalability and use of different mass ions as the plasma source.

The 1 m DPS that we have at Imperial will enable the outstanding measurements and improvements of uniformity and reproducibility to be made.

This project aims to develop suitable methods to measure, control and optimise a DPS for use in PWFA. This includes designing and implementing improvements to the DPS electronics, developing longitudinal and transverse diagnostics to determine the uniformity of the plasma and modelling the interaction between the SPS proton bunch and the DPS to determine optimal plasma profiles.

The project will be based at Imperial with opportunities to travel to CERN to implement the findings. This PhD is suitable for Physics or Engineering students, but funding is only available for UK applicants. All applications should be received by the 16th August.

[1] Caldwell, A., Lotov, K., Pukhov, A. et al. Proton-driven plasma-wakefield acceleration. Nature Phys 5, 363-367 (2009). https://doi.org/10.1038/nphys1248

[2] Turner, M. et al. (AWAKE Collabortion). Experimental observation of plasma wakefield growth driven by the seeded self-modulation of a proton bunch. Phys. Rev. Lett. 122, 054801 (2019). https://doi.org/10.1103/PhysRevLett.122.054801

[3] Adli, E., Ahuja, A., Apsimon, O. et al. Acceleration of electrons in the plasma wakefield of a proton bunch. Nature 561, 363-367 (2018). https://doi.org/10.1038/s41586-018-0485-4