Analysis of Oscillations in the Gyrotron Travelling Wave Amplifier.
Abstract
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 29, 1980
- Accession Number
- ADA091586
Entities
People
- Kworay Chu
- Larry R. Barnett
- Victor L. Granatstein
- Yueying Lau
Organizations
- United States Naval Research Laboratory