The Insulator at the Front of a Pulsed Power Machine

Summary form only given. We have recently shown that under certain circumstances the stacked-ring insulator at the front of a pulsed power machine can be replaced with a single monolithic insulator tube. We have used detailed charged particles tracing techniques to design such a monolithic insulator so that vacuum surface flashover is avoided. This technique has been first introduced for the explanation of the mechanism responsible for improved voltage holdoff in high gradient insulators (HGI) and their optimization with respect to vacuum surface breakdown. The success of this method was experimentally demonstrated in HGI. Here we present PIC simulation results which support our earlier ray tracing predictions. Moreover, in machines with a central tube carrying a current, the magnetic field due to this current flow deflects electrons further away from the surface of the monolithic insulator, decreasing even more the possibility for vacuum surface flashover.