Generation of intense excimer radiation from high-pressure hollow cathode discharges

TLDR

By reducing the cathode opening diameter to about 100 µm, the hollow cathode discharge can operate in noble gases in direct‑current mode up to atmospheric pressure. High‑pressure xenon discharges generate intense excimer radiation, peaking at 172 nm at 400 Torr, delivering 6–9 % of the input electrical power as VUV radiant power and enabling flat‑panel lamps with radiant emittances exceeding 50 W cm⁻².

Abstract

By reducing the diameter of the cathode opening in a hollow cathode discharge geometry to values on the order of 100 μm, we were able to operate these discharges in noble gases in a direct current mode up to atmospheric pressure. High-pressure discharges in xenon were found to be strong sources of excimer radiation. Highest intensities at a wavelength of 172 nm were obtained at a pressure of 400 Torr. At this pressure, the vacuum ultraviolet (VUV) radiant power of a single discharge operating at a forward voltage of 220 V and currents exceeding 2 mA reaches values between 6% and 9% of the input electrical power. The possibility to form arrays of these discharges allows the generation of flat panel VUV lamps with radiant emittances exceeding 50 W/cm2.