Total yield and spectra of positrons produced by channeling radiation from 0.1 ÷ 1.6 GeV electrons

The hybrid scheme of positron source involving channeling radiation from 0.1 ÷ 1.6 GeV 〈1 0 0〉 channeled electrons in a crystalline W target (radiator) and subsequent electron-positron pair production in a downstream thick amorphous W target (converter) is investigated by means of computer simulation using the BCM-1 code. Computer simulation is carried out taking into account positron energy loss in a thick converter. Total yield of positrons as a function of the thickness of the converter as well as the energy spectrum of positrons for the chosen converter thickness are obtained. According to the calculations, the total yield of positrons produced by channeling radiation from 0.1 ÷ 1.6 GeV electrons in a 10 µm W crystal equals 0.5 ÷ 160 positrons per 103 incident electrons, respectively, with the maximum of positron energy spectrum in the energy range 1 ÷ 3 MeV. Calculations are performed within the framework of the planned experimental program at SPARC_LAB LNF.