A PERIODIC MAGNETIC FOCUSING SYSTEM FOR TRANSPORTING AN ELECTRON-BEAMIN A LONG PLASMA CHANNEL

A system for transporting an electron beam (18-20 kV, 2-5 A) in a long plasma channel is described. A model of the system is based on an ana lysis of the beam stability in an alternating magnetic field and yield s the parameters of the electron beam injected into the focusing chann el. An electron beam gun generating the beam with the required paramet ers has been designed given the real magnetic field configuration, gas ionization in the accelerating gap, and the self-consistent position of the plasma boundary downstream of the anode. Experimental data on t he beam transportation in the focusing system are in agreement with th e basic results of a numerical simulation.