Analysis of Oscillations in the Gyrotron Travelling Wave Amplifier.
NAVAL RESEARCH LAB WASHINGTON DC
Pagination or Media Count:
The operation of the gyrotron travelling wave amplifier is based on the convection cyclotron maser instability. It is found that this convective instability may become absolute nonconvective at a sufficiently high current level, resulting in oscillation instead of amplification. This is threshold current for the transition depends sensitively on the applied magnetic field. The axial wavelength and the characteristic frequency of oscillation at the onset of absolute instability are given. It is found that momentum spread has virtually no effect on the threshold current. A small amount of resistive wall loss, however, raises the threshold current significantly. Oscillations due to partial reflection at the ends of the system are also examined. Preliminary experimental results on both types of oscillations are reported and are found to be in good agreement with the theory. Author
- Electrical and Electronic Equipment
- Particle Accelerators