Simulation Investigation of an Improved MILO

Magnetically insulated line oscillator (MILO) is a gigawatt-class high-power microwave source whose behavior has been investigated experimentally and numerically. This paper presents an improved MILO model. A novel beam dump, a one-cavity RF choke section and a novel mode-transducing antenna are introduced into the improved MILO. The improved MILO is investigated in detail with particle-in-cell method (KARAT code). In simulation, high-power microwave of transmission electron microscopy (TEM) mode is generated with peak power of 4.2 GW, frequency of 1.76 GHz, and peak power conversion efficiency of 12%, when the voltage is 600 kV and the current is 52 kA. A novel plate-inserted mode-transducing antenna, which is composed of a plate-inserted mode converter and a coaxial horn, is introduced into the improved MILO. The TEM wave generated by the MILO propagates down the section of coaxial waveguide and is transformed into the TE11mode by the novel plate-inserted mode converter, and then radiated by the coaxial horn antenna into air. The direction of the radiated microwave agrees with the axis of the MILO