Faraday Cup Measurements of Multiple Nanosecond Pulsed High-Current Electron Beam Generation from MICDS

Abstract

This study aims to validate analytical and PIC simulation results of generating multiple electron beams from nested magnetically insulated coaxial diodes (MICDs) at a single potential powered by a single power supply and transported in a smooth cylindrical drift tube. Previous analytical and simulation results of generating multiple electron beams are in good agreement [1] , [2] . The authors are in the process of measuring the electron beam current generated from the two thin annular beams using a Faraday cup (FC), a well-known technique to measure current from a pulsed relativistic electron beam accelerator. The SINUS-6 accelerator produces 15 ns electron beams with maximum current 4 kA at a maximum applied voltage of about 700 kV. The goal here is to produce two electron beams with comparable currents and 10-20% energy difference for a TWT [3] . We present preliminary measurements of electron beam current and current density as a function of radius with an estimate of electron beam energy from these measurements. The 45 mm diameter FC diagnostic is set up at the end of the drift tube output window where the FC probe comprises a semi-rigid coaxial cable with a center conductor connected to a graphite collector (cup). Our most recent measurements will be presented.