An atmospheric pressure inductively coupled microplasma source of vacuum ultraviolet light

Abstract

An inductively coupled microplasma source operating under atmospheric pressure was fabricated as a vacuum ultraviolet (VUV) light source. The microplasma source consisted of a quartz capillary tube (OD: Ø1.5mm, ID: Ø1mm) surrounded by a coil antenna. A floating wire electrode was set inside the tube to induce a high electrical potential. Under He gas flow (0.5slm), 100MHz VHF power was supplied to the coil antenna. The microplasma source easily achieved plasma ignition under ambient conditions. To extract the VUV emissions from the microplasma, an optical system was designed. VUV emissions of N, O, and H were obtained from the microplasma source operated at 10W of VHF power at 100MHz. The inductively coupled microplasma source operating at atmospheric pressure was further miniaturized using MEMS technology with the goal of developing an easily transportable device. The size of the fabricated microplasma chip was 20mm×3mm. The chip generated a point-like microplasma of Ø200μm at a VHF power of 24W. The point-like microplasma emitted clear spectral lines.