Development of high-frequency gyrotrons using high harmonics and a high magnetic field

Abstract

Our gyrotrons developed at the Research Centre for the Development of the Far Infrared Region, Fukui University (FU), are high-frequency medium-power gyrotrons used as millimetre- to submillimetre-wave radiation sources for application to new far-infrared technologies. We have already developed a gyrotron FU series which consists of eight gyrotrons. The gyrotron series has achieved frequency tuneability in a wide range (from 38 to 889 GHz). The highest frequency corresponds to a wavelength of 337 μm. This is a current record for high-frequency operation of gyrotrons. Recently, we have developed a high-harmonic gyrotron with an axis-encircling electron beam and a terahertz gyrotron with a pulse magnet. In this paper the present status of the gyrotron FU series is described.