Peculiarities of plasma channel formation in long drift tubes

Investigated is the formation of plasma channel during the injection of a power electron beam with the duration equal to several dozen nanoseconds (8x10-8 s) in long drift tubes, filled with air at different pressures p=1-40 torr. It is shown by numerical simulation that with the growth of pressure and the increase of the drift tube length, plasma current, induced in the channel, and total magnetic field become essentially nonuniform along the axis of beam propagation. Evaluations of the effect of a magnetic field nonuniformity on the transverse beam dimensions are carried out