Selective suppression of high order axial modes of the gyrotron backward-wave oscillator
- Department of Physics, National Tsing Hua University, Hsinchu 30043, Taiwan (China)
Selective suppression of high order axial modes of the gyrotron backward-wave oscillator (gyro-BWO) is investigated in theory and in experiment. The gyro-BWO interaction is much more efficient in a down-tapered interaction structure, while it is also more susceptible to the problem of axial mode competition in such a structure. Because higher order axial modes (at a higher oscillation frequency) penetrate deeper into the interaction structure, application of distributed wall loss at the downstream end of the interaction structure is shown to be effective for selective suppression of these modes with minor effects on the efficiency of the desired fundamental axial mode. A stable gyro-BWO operating in a single mode throughout the entire beam pulse is demonstrated on the basis of this principle. Theoretical and experimental results are found to be in good agreement.
- OSTI ID:
- 21069846
- Journal Information:
- Physics of Plasmas, Vol. 14, Issue 9; Other Information: DOI: 10.1063/1.2773708; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of tapering structures on the characteristics of a coaxial-waveguide gyrotron backward-wave oscillator
A broadband gyrotron backward-wave oscillator with tapered interaction structure and magnetic field