Vircator operation at plasma assistance

The influence of plasma on the processes of virtual cathode (VC) formation, high frequency (HF) generation, and plasma ions acceleration were studied. The theoretical consideration of the problem was analytically undertaken in one-dimensional approximation, that has shown the principal ability of low frequency (LF) oscillations of VC potential well and ion flow due to the periodic space charge neutralization by plasma ions. The experiments were carried out at the pulsed electron accelerator “AGAT”, which is a microsecond diode with a magnetic insulation. The accelerator produced an annular relativistic electron beam (REB). Plasma was produced by the beam electrons. It was observed that relaxing VC with low frequency modulation of 20 MHz was formed. The current of REB was temporary modulated at this frequency. The temporal modulation of intense REB is now proposed for excitation of slow space charge wave when further REB is being spatially modulated by periodic magnetic field. It constructs the scheme of the collective ion accelerator.