Overall simulation of a positron beam generated by photons from channeled multi-GeV electrons

Simulations of a nonconventional positron source, using a 1.5-20-GeV electron beam impinging on an assemblage of a tungsten crystal oriented along its <111> axis and an amorphous target of the same material, are presented. An overall simulation taking into account photon creation in the optimum length of the crystal, positron generation in the target, and positron capture and transport allows optimization of the source. Positron yield has been calculated for different operating conditions. This crystalline positron source features a higher level of photon radiation compared to classical bremsstrahlung; a positron production enhancement of the same order as the radiation increase; and the possibility of using thin amorphous targets behind the crystal, which allows weak positron transverse momentum and lowers the amount of deposited energy in the target.<>