Photocathode laser based bunch shaping for high transformer ratio plasma wakefield acceleration

3rd European Advanced Accelerator Concepts workshop, EAAC 2017, Elba, Italy, 24 Sep 2017 - 30 Sep 2017; Nuclear instruments & methods in physics research / A 909, 107 - 110 (2018). doi:10.1016/j.nima.2018.02.043
Beam driven plasma acceleration is one of the most promising candidates for future compact particle accelerator technologies. In this scheme a particle bunch drives a wake in a plasma medium. The fields inside of the wake can be used to accelerate a trailing witness bunch. To maximise the ratio between acceleration of the witness to deceleration of the drive bunch, the so called transformer ratio, several methods have been proposed. The ones yielding the most favorable results are based on shaped drive bunches that are long in terms of the plasma wavelength. We present here methods to create such drive bunches employing temporally shaped UV-laser pulses for the extraction of electron bunches from a photo-electron gun. Theoretical considerations, experimental results and possibilities for further improvements are discussed.
Published by North-Holland Publ. Co., Amsterdam