Parametric tolerance study of Trojan Horse plasma wakefield acceleration scheme

A promising scheme for plasma wakefield acceleration is the hybrid plasma acceleration mechanism, which is experimentally connected to world-wide programs at various accelerator facilities. This scheme may lead to extremely high quality electron bunches, which can be used to drive ultrabright light sources such as free electron lasers. The big challenge for plasma acceleration is to produce electron bunches with high quality in terms of low emittance, energy spread and high brightness. To overcome this challenge, the Trojan Horse scheme [1,2,3,4,5] is used for production of designer electron beams. This work explores the Trojan Horse mechanism in a parametric study by variation of the injector laser pulse by intensity a0, spot size w0 and relative spatiotemporal synchronization and alignment. These parameters define output electron witness beam parameters and its quality. This sensitivity study shows a high robustness of the scheme, which is promising for a wider key prospect of the approach, namely the development of compact plasma accelerators to produce electron beams with unprecedented emittance and brightness in order to power free-electron lasers

Plasma accelerator driven coherent spontaneous emission

Plasma accelerators [1] are a potentially important source of high energy, low emittance electron beams with high peak currents and generated within a relatively short distance. While novel plasma photocathodes [2] may offer improvement to the normalised emittance and brightness of electron beams compared to Radio Frequency-driven accelerators, a challenge is the energy spread and chirp of the beams, which can make FEL operation impossible. In this paper it is shown that such an energy-chirped beam, with a dynamically evolving current profile due to ballistic bunching, can generate significant coherent radiation output via the process of Coherent Spontaneous Emission (CSE) [3]. While this CSE is seen to cause some FEL-induced electron bunching at the radiation wavelength, the dynamic evolution of the energy chirped pulse dampens out any high-gain FEL interaction

Advanced schemes for underdense plasma photocathode wakefield accelerators : pathways towards ultrahigh brightness electron beams

The 'Trojan Horse' underdense plasma photocathode scheme applied to electron beam-driven plasma wakefield acceleration has opened up a path which promises high controllability and tunability and to reach extremely good quality as regards emittance and five-dimensional beam brightness. This combination has the potential to improve the state-of-the-art in accelerator technology significantly. In this paper, we review the basic concepts of the Trojan Horse scheme and present advanced methods for tailoring both the injector laser pulses and the witness electron bunches and combine them with the Trojan Horse scheme. These new approaches will further enhance the beam qualities, such as transverse emittance and longitudinal energy spread, and may allow, for the first time, to produce ultrahigh six-dimensional brightness electron bunches, which is a necessary requirement for driving advanced radiation sources