HFSS and CST Simulations of a GW-Class MILO

A magnetically insulated line oscillator (MILO) was studied using the simulation software packages high-frequency structure simulator (HFSS) and Computer Simulation Technology-Particle Studio (CST-PS). HFSS was used to find dispersion characteristics of the slow-wave structure and predict resonant-mode frequencies. CST-PS was used to analyze the operation of the device with space charge included. At an applied voltage of 500 kV, CST-PS predicted 1.25-gigawatt (GW) microwave generation at 1.2 GHz while drawing 57 kA. These simulations are consistent with previously published experimental results for a similar MILO. The CST-PS model was used to predict MILO operation as a function of injected voltage, and a separate study was performed to evaluate the effects of an independent, externally applied axial magnetic field. These simulation efforts are in support of upcoming experiments at the University of Michigan, where the MILO investigated in this article will be tested on a new linear transformer driver facility.