Mode competition and startup in cylindrical cavity gyrotrons using high-order operating modes
The problem of mode competition in cylindrical cavity gyrotrons is considered. The normalised variable equations are used to calculate the oscillation regions of possible operating modes in the energy-velocity-pitch-angle plane. The analysis is self-consistent and includes the effect of changing beam current, pitch angle and energy during the startup phase. The time evolution of beam parameters during startup is computed for several types of startup methods and used to determine the oscillating cavity modes during startup. The accessibility to the high-efficiency hard excitation region is seen to depend on the startup scenario. The method is general and can be applied to any operating mode, with the mode competition analysis particularly useful for high order modes where the spectrum is dense. The analysis of the accessibility to the hard excitation region is applicable to high and low order operating modes. Both q = 1 and q = 2 longitudinal mode numbers are considered.
Bibliographic Reference: Report: LRP 484/93 EN (1993) 38 pp.
Availability: Available from Confédération Suisse, Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Fédérale de Lausanne, 21 avenue des Bains, 1007 Lausanne (CH)
Record Number: 199311455 / Last updated on: 1994-11-28
Original language: en
Available languages: en