4th European Advanced Accelerator Concepts Workshop

Minimizing betatron coupling of energy spread and divergence in laser-wakefield accelerated electrons

17 Sept 2019, 16:00

20m

SML (Hotel Hermitage)

talk WG1 - Electron beams from plasmas WG1 - Plasma acceleration physics I

Speaker

Alexander Koehler (Helmholtz-Zentrum Dresden - Rossendorf)

Description

Matched beam loading in laser wakefield acceleration (LWFA) flattens the accelerating electric field along the bunch and leads to the minimization of energy spread at high bunch charges. By using the self-truncated ionization injection scheme for controlling the injected charge, we demonstrate that minimal energy spread coincides with a reduction of the normalized beam divergence.
Betatron radiation spectroscopy simultaneously confirms a constant beam radius at the plasma exit. Together, the decrease in divergence can be attributed to the reduction of chromatic betatron decoherence. Thus, beam loading enables the highest longitudinal and transverse phase space densities by optimizing energy spread and normalized divergence.