本論文主要分為兩部份，第一部分為磁旋返波震盪器的基本特性，包含暫態行為(transient behavior)、剛起振時的線性行為(linear behavior)，和高電流時的飽和行為，第二部分為利用鮑國峰學長所發展出來的PIC（particle in cell）隨時變的程式來分析其不穩定的現象，並希望藉由電磁場和電子吸吐能量率(energy deposition rate)的時空變化關係來觀察其回饋路徑(feedback loop)的關係，希望能對磁旋返波震盪器中所發生的不穩定行為能有其更好的解釋與分析．

My thesis is composed by two parts.
One is the basic physics of gyrotron back-ward oscillator.The basic physics is the behavior of gyro-Bwo in transient, linear, saturated state.
The other is the nonstationary behavior of gyro-BWO analyzed by PIC code. To see the time-dependent behavior of gyro-BWO.

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