Measurements of Electron Beam Characteristics

in the Moderate-Power 4-mm Gyrotron

D. Kas’yanenko, O. Louksha, B. Piosczyk1, G. Sominski, M. Thumm2,

Saint-Petersburg State Polytechnical University (SPbSPU), 29 Polytechnicheskaya St., St. Petersburg 195251, Russia

1 Forschungszentrum Karlsruhe, Association EURATOM-FZK, Institut fuer Hochleistungsimpuls-
und Mikrowellentechnik (IHM), Postfach 3640, D-76021 Karlsruhe, Germany,

2 and Universitaet Karlsruhe, Institut für Höchstfrequenztechnik und Elektronik

e-mail: louksha@rphf.spbstu.ru

In the 74.2 GHz moderate-power pulse gyrotron, influence of low-frequency parasitic oscillations in the electron beam tunnel on electron energy spread is determined. A method for suppressing parasitic oscillations by using non-uniform magnetic field in the compression region is studied. The characteristics of the electron beam in dependence of azimuthal inhomogeneity of electron emission have been investigated