Simulation of HPIB propagation in biased charge collector

A 2.5D PIC simulation using KARAT code for inner charge propagation within biased charge collector for measuring HPIB was presented. The simulation results indicated that the charges were neutralized but the current non-neutralized in the biased charge collector. The influence of ions collected vs biased voltage of the collector was also simulated. －800V biased voltage can meet the measurement of 500keV HPIB, and this is consistent with the experimental results．