Runaway-electron-preionized diffuse discharge at atmospheric pressure and its application

Abstract

The paper presents the results of experimental research on nanosecond high-pressure diffuse discharges in an inhomogeneous electric field with a time resolution of ∼100 ps. It is shown that decreasing the voltage pulse duration enhances the feasibility of the diffuse discharge with no additional ionization. In particular, with a narrow interelectrode gap, a diffuse discharge in atmospheric pressure air with preionization by runaway electrons, called a runaway-electron-preionized (REP) diffuse discharge (DD), was realized. It is found that most of the energy is deposited to the REP DD plasma once the voltage across the gap reaches its maximum. It is demonstrated that the REP DD holds promise for producing high-power VUV pulses. The radiation power attained with xenon at a wavelength of ∼172 nm is 8 MW. The treatment of an AlBe foil with an REP DD in atmospheric pressure air provides cleaning of its surface layer from carbon and penetration of oxygen atoms into the foil to a depth of 450 nm per 300 pulses.