Generation of accelerated electrons in nanosecond electrical discharges using extensive slot cathodes limited by dielectric walls

The spatio-temporal formation dynamics and basic electrical and optical characteristics of nanosecond discharges with an extended slot cathode in helium are investigated. It is established that electrons ribbon beams are formed in such discharges with an energy of several hundred eV. It is demonstrated that the restriction of the discharge gap in dielectric walls leads to the trapping of electrons in the gap and an increase in the efficiency of excitation and ionization of atoms of beam electrons, which leads to a substantial increase in the current density and intensity of optical radiation of the limited discharge. Experimental data obtained on the relaxation of charge density on the deposited surface of the charge limiter and the value estimates of the electric potential of the dielectric surfaces, were analysed. It is demonstrated that the variation in the discharge structure restricted by the dielectric walls corresponds to the variation in the distribution of the electric field in the gap, as well as under the influence of the surface potential.