Gyrokinetic Analysis of Electron-Beam-Misalignment Effect on a Far-Infrared Gyrotron

Gyrokinetic study is presented to the effect of the electron-beam misalignment on a far-infrared cylindrical-cavity gyrotron oscillator constructed by a Japanese research group. Agreement is found between the theory and the experimental observation. The influences of the operating magnetic field and the electron-beam energy are discussed with the electron-beam misalignment taken into account. It is found that the starting current notably increased because of the existence of the electron-beam misalignment.