Design of a toroidal cathode negative polarity re-entrant rod pinch diode for operation at 2 – 3MV

Summary form only given. Previous work at AWE has demonstrated the successful operation of the rod pinch diode using the toroidal cathode geometry at approximately 1 MV. The geometry has been developed to give an unrestricted view of the tip of the rod when the diode is used in negative polarity operation. This geometry is most useful when the diode is to be used at low voltages (<4MV) and the driver is limited such that only negative polarity operation is possible. This presentation reports the work carried out to design a toroidal cathode geometry to operate on the EROS pulsed power driver at 2-3 MV. It includes 3D powerflow simulations using the particle-in-cell code Lsp and results from initial experiments of the diode carried out on the EROS driver.