Optimization of BEPC positron source

Based up on Monte-Carlo simulation and particle tracking, the positron source of BEPC is designed and the predicted performance is compared with experimental measurement with good agreement. Important conclusions can be drawn from the study, such as:up to 10A, increase in electron gun current is beneficial in spite of the deterioration effect on the beam spot size at the traget; positron current increases with the bridge coil and solenoid coil currents and nearness of the positrion of matching field peak to the target; the existance of two injection phases and their significance; the electron and positron from the target do not have to be separated and the R.F. separator is not necessary etc.. The above results serve the purpose of directing the tune-up and operation of BEPC, providing a useful reference for future design of positron accelerators