High-harmonic terahertz gyrotrons with sectioned cavities

Summary form only given. As is known, the operating magnetic fields in gyrotrons can be significantly decreased by using high-cyclotron-harmonic radiation of an axis-encircling electron beam. This configuration of so-called Large Orbit Gyrotron (LOG) improves both the electron-wave coupling and mode selectivity. Recently, a unique third-harmonic 1 THz/80 kV LOG has been realized at the IAP [1]. It should be noticed that because of relatively low electron current a long-length operating cavity with a very high diffraction Q-factor has been used in this oscillator. As a result, a great share (80–90%) of radiated THz power is spent to Ohmic losses.