Theoretical And Experimental Study Of The C-band Magnetically Insulated Transmission Line Oscillator

The magnetically insulated line oscillator (MILO) is a gigawatt-class coaxial crossed -field microwave tube. The primary characteristic of the MILO is that it requires no externally applied magnetic field to insulate the electron flow under the slow wave structure. The tube can be compact, lightweight and can handle an extremely large input beam power. This dissertation is mainly about the high frequency characteristics of the C-band MILO and the effect of the electromagnetic field and the RF field on electrons. Through the numerical simulation and the experimental research, the structural parameters and working parameters of the C-band MILO are adjusted for increasing the microwave output power. A series of valuable results are obtained.A two-dimension fully electromagnetic Particle-In-Cell (PIC) simulation is applied to study the eigenfrequencies and their field distributions of the SWS. The relation between the operating frequencies and the structure parameters is obtained. Then we feed power to the system at the third cavity and study the high frequency characteristics of the C-band MILO with open boundary.Firstly the theoretical analysis of electrons movement in the MILO is made under the condition of planar electrode approximation. Then we study the effect of the electromagnetic field and the RF field on electrons. Through numerical simulation, the relation between the RF field and spokes is discussed in this paper.The effects of many structural parameters and working parameters on output power and frequencies are studied. The structure of the C-band MILO is designed and optimized. The simulation results show that the C-band MILO can generate an average power of 2GW with the efficiency of 10% at 3.51 GHz frequency.In the last part of this dissertation, the microwave power, the frequency and the mode are measured, and the relations between the microwave radiation and beam parameters are investigated. In the experiments, the average output microwave power of 500MW with the efficiency of 3.8% is got from the C-band MILO. The C-band MILO exports the microwave in coaxial TM₀₁ mode at 3.7GHz.