Gas-laser pumping by an electron beam from the plasma of a nanosecond skimming discharge

Experiments on the possibility of pumping gas lasers with an electron beam produced in the active medium of the laser by means of a skimming discharged along a dielectric surface are reported. The spectrum, emission energy, and pulse shape of the laser beam operating under superradiance conditions were studied. The emission revealed a nonuniform energy distribution over the cross section, with ring emission being observed over essentially the entire range of working pressures except near the threshold for lasing. The maximum emission intensity was observed during the decay of the discharge current pulse. Lasing begins at the time at which the electron beam current reaches its maximum, furnishing evidence in favor of the mechanism of direct electron impact for creating the population inversion. The onset of emission and the duration of the emission pulse are determined by the temporal parameters of the electron beam current.