Plasma and Fusion Research

Volume 7, 1205004 (2012)

Rapid Communications

Formation of Laminar Electron Flow for a High-Power Sub-THz Gyrotron

Yuusuke YAMAGUCHI, Yoshinori TATEMATSU, Teruo SAITO, Ryosuke IKEDA, Jagadish C. MUDIGANTI, Isamu OGAWA and Toshitaka IDEHARA

: Research Center for Development of Far-Infrared Region, University of Fukui, Fukui 910-8507, Japan

(Received 3 December 2011 / Accepted 19 December 2011 / Published 27 January 2012)

Abstract

This paper describes the design of a magnetron-injection gun for a 100 kW, 300 GHz gyrotron. With an increase in power and frequency, performance of the gyrotron becomes quite sensitive to the quality of the electron beam. Formation of a laminar electron flow is essential for the realization of a high quality beam with small velocity spread. In this study, a new method is proposed for the evaluation of the laminarity, and applied to the design optimization of the electrodes. It is found that the laminarity depends not only on the conventional design parameter of the cathode slant angle, but also on the spatial distribution of the electric field inside the beam.

Keywords

gyrotron, magnetron-injection gun, space charge effect, velocity spread, laminar flow

DOI: 10.1585/pfr.7.1205004

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This paper may be cited as follows:

Yuusuke YAMAGUCHI, Yoshinori TATEMATSU, Teruo SAITO, Ryosuke IKEDA, Jagadish C. MUDIGANTI, Isamu OGAWA and Toshitaka IDEHARA, Plasma Fusion Res. 7, 1205004 (2012).