Numerical simulation of erosion switch performance on the PITHON generator

A model for the operation of a plasma erosion switch on the PITHON generator is presented. The switch region of the PITHON vacuum feed is modeled as a lossy transmission line whose shunt conductance corresponds to space charge limited, bipolar flow across a cathode sheath transitioning smoothly to single species ion flow after the onset of magnetic insulation. Model calculations are shown to be in good agreement with results of recent erosion switch experiments on PITHON.