Numerical investigation of terahertz wave driven electron acceleration generated from gas jet

We have investigated the dependence of the acceleration efficiency for three different proposed direct terahertz wave driven electron accelerator setups, including ionization in a gas jet source. We have numerically simulated and optimized the ionization processes using Particle-In-Cell code (EPOCH) and pointed out its crucial effect on the accelerating mechanism. Supposing two single-cycle terahertz driving pulses with 1 mJ energy per pulse we characterized the different accelerator arrangements. The main properties of the predicted electron beams with the average kinetic energy of 27 keV can be adapted to the requirements of different applications in the fC-pC charge range.