The cylindrical geometry of the superdense magnetron type discharge system version in the crossed electric and magnetic fields is attractive in that it allows a high azimuthal uniform plasma emission surface to be formed. This geometry offers no problem with screening the cathode from the magnetic field of the beam transportation region. There is a stabilizing effect of magnetic field on the discharge, which provides high value of discharge current in the diffuse (without cathode spots) phase of discharge operation. Thus, for a cathode surface area of 300 cm2 and a pulse duration of 15 microsecond(s) , the maximum current of a discharge in He was 1.5 kA, in a steady-state mode is was more than 10 A. The processes of electron and ion emission have some peculiar features, and the experimental results of this investigation are also presented. In our device, for a 20 microsecond(s) pulse duration and energy of 200 keV it was possible to obtain an electron beam current of 600 A with a current density of 75 A/cm2. The beam mean diameter and width were, respectively, 10 cm and 1 mm. The electron current in the steady-state mode was 2 A with a 10 keV energy. The ion beam current constitutes of 10% of the discharge current. The application fields of these sources are microwave generation, surface properties modification, etc.
|