Design and test of a Faraday cup for low-charge measurement of electron beams from laser wakefield acceleration

Nowadays, laser wakefield acceleration is considered to be one of the perspective methods for GeV electron beam production. The combination of laser accelerated electrons and Compton backscattering of a probe light beam opens the possibility of creating the tabletop source of a femtosecond light beam in x-ray and gamma ranges. The project is aimed at creating a laser-driven Compton light source in ILP SB RAS in collaboration with BINP SB RAS. Production of 1-10 pC electron beams in sub-ps time range duration with energies up to 100 MeV is expected to be a result of the first stage of the project. Since the energy of electrons does not exceed 100 MeV, it allows the use of the Faraday cup (FC) with reasonable dimensions, instead of the commonly used integrating current transformer. The geometry of the FC has been optimized taking into account beam stopping simulation as well as a low capacity requirement. Simulation of high-frequency properties of the entire system was carried out. The system has been tested at the VEPP-5 electron linac. The results of developing and testing this FC are presented.