Study of the Weibel instability in a fast wave device

Summary form only given. In the gyrotron device, the linear theory predicts two branches of the instability: the fast-wave cyclotron resonance maser (CRM) instability and the slow-wave Weibel instability. The CRM instability forms the basic mechanism of gyrotron oscillators and amplifiers. It is still unclear how the Weibel instability behaves in the fast wave device. A particle tracing code which calculates the self-consistent field profile and a particle-in-cell simulation code are applied simultaneously to examine the validity of the linear theory on the prediction of the linear gain and reveal the actual effect of the intrinsic Weibel mechanism on the gyrotron device.