Sensitivity study in a compact accelerator for laser-generated protons

A sensitivity study is presented here on a compact hybrid postacceleration scheme coupling laser-generated protons to a high frequency Linac based on the use of a SCDTL (Side Coupled Drift Tube Linac) structure. The study analyzes the main laser-generated beam characteristics and the most important parameters linked to the accelerating structure. We show that the required tolerances regarding alignment and field uniformity, although challenging, are within the reach of actual technology. Regarding the laser-generated proton beam parameters (spot size and divergence), we show that they have only a little influence on the final emittance that is mainly determined by the capturing and accelerating structure. However, these parameters can sensitively affect the final transmission of the proton beam current.