Experiment for Over 200 kW Oscillation of a 295 GHz Pulse Gyrotron

Abstract

A high-power sub-THz gyrotron is under development as a power source of collective Thomson scattering diagnostic of fusion plasmas. It operates at a fundamental harmonic frequency of 295 GHz. A cavity which realizes stable and efficient single mode oscillation, an electron gun with an intense laminar electron beam, and an internal mode convertor are designed. A maximum oscillation power of 234 kW is achieved with a Gaussian like radiation pattern. The duration of 130 kW pulse is extended up to 30 microseconds, which is limited by the configuration of power supply.

Recent progress in development and application of sub-THz gyrotrons in University of Fukui

“…We also developed pulsed high power gyrotron series [20][21][22][23][24][25][26][27][28]. They are developed in the purpose of a light source for the Collective Thomson Scattering (CTS) measurement in LHD, NIFS.…”

“…Since 2006, gyrotrons have been developed in FIR-UF for the purpose of applications such as DNP-NMR spectroscopy [5,6], sintering and direct measurement of energy level of positronium hyperfine structure [7]. Gyrotrons developed for this purpose are Gyrotron FU CW series [8][9][10][11][12][13], Gyrotron FU CW G series [14][15][16][17][18][19] and pulsed gyrotrons [20][21][22][23][24][25][26][27][28].…”