Investigation Of A Compact L-Band Magnetically Insulated Transmission Line Oscillator

The magnetically insulated transmission line oscillator (MILO) is a gigawatt-class, coaxial crossed-field device that requires no externally magnetic field to insulate the electron flow under the slow-wave structure. This self-insulating property, inherent in magnetically insulated transmission lines, allows the tube to handle an extremely large input beam power(tens of gigawatts)without ensuing electrical breakdown of the anode-cathode gap. There exists great importance in the investigation both into the fundamental physics related to the beam-wave interaction and into the rule of electrons movement in this device. This dissertation presents preliminary analysis in theory, particle simulation, and experimental investigation on the physical mechanism of the MILO. A series of reasonable and valuable results are obtained from this work.This paper preliminarily analyses in theory the physics of microwave generating and amplifying, and the basic theory of MILO operating .The relations among MILO's frequency, output power, the power conversion efficiency and geometry parameters are presented in simulation. When the input voltage is 550kV, and the diode current is 82kA, high power microwaves are generated from the model with the frequency of 1.9GHz, the output power of 5.4GW, and the power conversion efficiency of 12% in simulation.This paper presents the experimental configuration and its layout of RF choke cavities, the stubs and the mode converters in the investigation of the configuration. According to the parameters of the self-built accelerator , a compact L-band magnetically insulated transmission line oscillator (MILO) is configured and fabricated. When the input voltage is 540kV, and the diode current is 49kA, high power microwaves are generated from the model with the frequency of 1.75GHz, the output power of 2.3GW, and the power conversion efficiency of 8.7% in simulation.The compact L-band magnetically insulated transmission line oscillator (MILO) is experimentally investigated. In the experiments, high power microwaves of the TM01 mode are generated from the device with the frequency of 1.76GHz, output power of 2.55GW, and the power conversion efficiency of 7.8% when the input voltage is 538kV ,and the diode current is 61kA.The experimental results agree well with that of simulation.