Performance evaluation of electron beams and structure optimization of thermionic-cathodes in THz gyrotrons

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K21030
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Plasma science; Electron device/Electronic equipment
• Research Institution: University of Fukui
• Principal Investigator: Yamaguchi Yuusuke 福井大学, 遠赤外領域開発研究センター, 特命助教 (10466675)
• Research Collaborator: TATEMATSU Yoshinori 福井大学, 遠赤外領域開発研究センター, 准教授 (50261756) ; SAITO Teruo 福井大学, 遠赤外領域開発研究センター, 教授 (80143163)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: ジャイロトロン / テラヘルツ / マグネトロン入射型電子銃 / ラミナー流 / 含浸カソード / 熱絶縁

Outline of Final Research Achievements

The magnetron-injection-guns (MIGs) are a critical component of gyrotrons which are operated in the THz range of frequencies. The emitter is made of porous tungsten impregnated with barium compounds. There are small gaps in order to thermally isolate the emitter from the other elements of the cathode. In this study, two kinds of MIG cathodes with different gap position arrangements were fabricated in order to investigate the effect of those gaps on electron beam characteristics. Each cathode was installed and tested in a 0.2-THz gyrotron. The oscillation characteristics associated with the electron beam properties were evaluated by comparing the observed results and the numerical ones. Although the substantial decreases in the electron beam quality and the output power were numerically predicted in case of the thermal insulation gaps close to the emitter, the reductions were small under the optimized experimental conditions.

Free Research Field

高周波工学