DENSITY-MEASUREMENT OF O-ATOMS IN HELICON WAVE OXYGEN DISCHARGE BY 2-PHOTON LASER-INDUCED FLUORESCENCE

Ground-state O atoms in oxygen plasma have been detected by means of t wo-photon laser-induced fluorescence at 226 nm. A calibration method f or obtaining the absolute O atom density was established, using O atom s produced by photodissociation of molecular oxygen with 226 nm photon s. The O atom density in helicon wave oxygen discharge was determined, and a typical value was 1.3 x 10(19) m(-3) at a gas pressure of 50 mT orr and electron density of 5.2 x 10(16) m(-3). Spatial and temporal v ariations of the O atom density have been successfully measured.