MAGNETIC-FIELD TAPERING IN THE KFK COAXIAL GYROTRON

Equations describing the magnetic field tapering in a gyrotron cavity with allowance for the dependence of the radius of the electron guidin g centers on the longitudinal coordinate are derived. Influence of the shift of the magnet of the KfK coaxial gyrotron along the gyrotron ax is on efficiency is studied. It is found that for the operating voltag e 90kV the optimal alignment is such that the maximum of the magnetic field is placed in the middle of the straight section of the cavity. F or 80kV the absolute values of the field must be reduced by factor 1.0 17, or the maximum of the field must be placed in the output taper of the cavity.