Beam-driven plasma wakefield acceleration in AWAKE

Abstract

Plasma wakefield acceleration is a very competitive novel acceleration concept for the future TeV-level lepton colliders due to its high acceleration gradient. The SPS or LHC protons stand out to be the most promising wakefield driver that is able to accelerate the witness beam to TeV energy in a single plasma stage. The AWAKE Run 1 experiment has successfully demonstrated the proton self-modulation and the electron acceleration to 2 GeV energy. In this thesis, by theory and particle-in-cell simulation, we systematically investigate the electron seeded proton self-modulation and electron witness beam acceleration in the AWAKE Run 2 experiments. The proton self-modulation growth is found to be subject to different seeding conditions as well as the tailored plasma density profiles, while the electron beam acceleration in the second plasma stage is affected by different beam loading and beam matching conditions. We have performed extensive simulation study and theoretical analysis to understand the physics in these processes. Additionally, we found non-Gaussian transverse beam profiles also impact the witness beam acceleration in the quasi-linear proton-driven wakefield. For the purpose of non-invasive beam diagnostics, we also studied the betatron radiation spectroscopy in AWAKE Run 2 and analysed the relation between the radiation spectral features and the beam dynamics. A numerical study of the long-term effect of the radiation loss--the radiation reaction effect is also presented in this thesis to understand its influence on the future TeV-level plasma-based accelerators.

Date of Award	31 Dec 2022
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Darren Graham (Supervisor) & Guoxing Xia (Supervisor)