The Monte Carlo Simulation of a 1-MW Neutral Beam Injector on RFX-Mod

The megawatt-level TPE-RX neutral beam injector is planned to be installed on the RFX-mod reversed field pinch (RFP) experiment. To properly integrate the TPE-RX injector on RFX-mod, a 3-D Monte Carlo simulation of the injector has been carried out. The code simulates the charged and neutral particle trajectories from the acceleration grids of the beam source to the RFP plasma. The simulation includes the neutralization stage, the interaction between the accelerated particles and the magnetic field produced by RFX and the residual ion dump (RID), and the interactions between the accelerated beam and the background gas. The simulation has allowed to estimate the neutralizer and RID efficiency and specifications, the geometry of the beam duct between the injector and RFX-mod, and the necessary degree of magnetic screening.