The Impact of Cathode Geometry on Electron Hot Spot Formation and Ion Beam Properties in Pinched-Beam Diodes

Electron and ion dynamics in a cylindrical pinched-beam diode with 1.6 MV, 800 kA, and 50 ns parameters were studied using particle-in-cell simulations to improve ion beam uniformity. In particular, this work explored how annular cathode tip thickness affected electron hot spot formation and the resulting ion beam. Simulations showed reduced electron hot spots and a more uniform ion beam for a 0.5-mm-thick cathode tip compared to a 3-mm-thick cathode tip.