Laser-plasma acceleration of polarised electrons up to energies of several TeV

Abstract

The process of multistage acceleration of polarised electrons in the wakefield of a relativistic femtosecond laser pulse is investigated. The main mechanism of the growth of slice emittance for a moderately nonlinear regime of laser-plasma acceleration is demonstrated. The main conditions for setting the initial parameters of the electron bunch are determined, which allow minimising the mixing of the phases of betatron oscillations of particles in the bunch slice and the emittance growth during acceleration. The method of smooth input of an electron bunch into the accelerating stage and its smooth removal from this stage is studied, which allows the main characteristics of the bunch to be preserved, such as emittance and polarisation, for further particle transportation and acceleration. The effect of the radiation friction force and the radiation polarisation mechanism on the process of particle depolarisation in acceleration to energies of ∼4 TeV in model fields characteristic of moderately nonlinear and strongly nonlinear regimes of laser-plasma acceleration is considered.