Three-dimensional particle-in-cell with Monte Carlo collision simulation of the electron energy distribution function in the multi-cusp ion source for proton therapy

Abstract

For optimization and accurate prediction of the amount of proton production in the multi-cusp ion source, analysis of the electron energy distribution function (EEDF) is necessary. A three dimensional particle-in-cell with Monte Carlo collision (PIC-MCC) code based on the CHIPIC software platform are developed. The code is applied to the multi-cusp proton source. The results show that there are two energy distributions in the discharge chamber, and a spatial non-uniformity of electron density due to the B⃗×∇B drift of the top permanent magnets is observed.