Electrical and optical characteristics of inert-gas plasmas in spatially nonuniform electrode systems

The characteristics of unipolar and bipolar corona discharges in mixtures He/Ar/Kr, He/Ar/Xe, and He/Kr/Xe at atmosphere pressures in electrode systems of the point-plane and point-grid type distributed along the length. It is shown that bipolar corona discharges can be used in the preionization systems of high-pressure inert-gas-atom lasers. The spectral characteristics of the plasma are investigated, and the dependence of the relative intensity of the radiation in the lines Ar(4s-4p), Kr(5s-5p), and Xe(6s-6p) on the composition and pressure of the working mixtures and on the value of the corona discharge current are determined. Zh. Tekh. Fiz. 67, 15–18 (November 1997)     

Optical characteristics of a transverse volume discharge in a helium-hydrogen chloride mixture

The emission characteristics of a transverse volume discharge in a He: HCl = 10: 1 mixture at a total pressure of 1–8 kPa were investigated. The plasma volume was 18 × 2.2 × 1 cm³, the interelectrode distance was d=2.2 cm, and the charging voltage of the main storage capacitor was 5–10 kV. The emission characteristics of the discharge were studied in the spectral range of 500–1000 nm. This type of discharge can be used in pulsed dry-etching plasmochemical reactors. The density of atomic chlorine radicals in the plasma was optimized in terms of the pressure of the initial working He-HCl mixture by measuring the relative radiation intensity of the Cl 837(5)-nm spectral line. The density of molecular radicals can be monitored indirectly by recording radiation from the excited chlorine-free decomposition products of HCl molecules (the H_α 656-nm line).     

Characteristics of a nanosecond discharge in atmospheric air with a liquid electrolytic electrode

The spatial, electric, and radiative characteristics of a pulse-periodic nanosecond discharge between an electrode based on a system of blades and the distilled water surface as well as an aqueous solution of zinc sulfate in atmospheric air are considered.     

A multiwavelength low-pressure radiation source based on argon and xenon chlorides

The characteristics of an excimer radiation source pumped by a subnormal dc glow discharge in an Ar/Xe/Cl₂ mixture with the source operating in a spectral range of 160–310 nm were studied. The emission intensities of the 175, 236, 258, and 308 nm bands due to the transitions ArCl (B-X), XeCl (D-X), Cl₂ (D′-A′), and XeCl (B-X), respectively, were optimized in relation to the pressure, composition, and discharge current of the mixture.     

Optical characteristics of a repetitively pulsed low-pressure discharge in a krypton-freon-12 mixture

Results of a study of the plasma radiation of a repetitively pulsed discharge in a Kr/CF₂ Cl₂ mixture (P≤1.5 kPa) in the 130–300 nm spectral range are presented. Spatial, spectral, and temporal characteristics of the discharge are studied in a spherical anode-plane cathode system, in which the repetitively pulsed mode is established due to the evolving instability of the glow discharge. It is demonstrated that a discharge of this type can be used for the development of a repetitively pulsed low-pressure bactericidal lamp which emits in the band system of KrCl (222 nm) and Cl₂ (257, 200 nm) in the 180–270 nm spectral range.     

Formation of argon fluoride molecules under interaction of an argon plasma flow with potassium fluoride and sulfur hexafluoride vapors

The formation of argon fluoride molecules in plasma-dynamic jets of argon-potassium fluoride vapor and argon-sulfur hexafluoride vapor mixtures is investigated. The intensity of the ArF* luminescence band at 193 nm versus the argon and sulfur hexafluoride flow rates, pump power, and distance from the nozzle is studied.     

Formation of monochlorides of heavy inert gases in a high-frequency transverse discharge plasma

Emission characteristics of a high-frequency transverse discharge plasma in mixtures of argon and xenon with chlorine molecules are presented. It is shown that the discharge in xenon-chlorine mixtures is a source of broadband radiation in the spectral region 220–450 nm, while in argon-chlorine mixtures, it emits in the region 150–270 nm. Double mixtures with a partial pressure of inert gases ranging within 300–400 Pa and a chlorine partial pressure of 30-40 Pa are found to be optimal. The mean output discharge power ranges within 15–50 W.     

Emission characteristics of a glow discharge plasma based on a mixture of helium with chlorine molecules

We present the results of a study of the emission characteristics of a longitudinal glow discharge based on a mixture of helium and chlorine. Study of the emission characteristics of the discharge showed that it emits most efficiently in the bands of the chlorine molecule with maxima at 200 nm and 258 nm in an He-Cl₂ mixture (P = 0.2–0.3 kPa). We present the optimization of the average emission power of a UV emitter as a function of the glow discharge parameters, the pressure, and the composition of the working gas mixture. Based on solution of the Boltzmann equation for the electron energy distribution function in a discharge based on the optimal mixture (according to experimental data), we calculated the power losses per unit pressure going toward elementary processes, the electron transport characteristics, the ionization and attachment coefficients as a function of the parameter E/P. The calculated parameters of the plasma for the UV emitter allowed us to provide a basis for the qualitative pattern of physicochemical processes in the studied plasma. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 1, pp. 121–124, January–February, 2008.     

Ultraviolet radiation sources on (H2O,D2O) water vapor

Emission characteristics of ultraviolet (UV) radiation from water vapor (H₂O, D₂O, and a mixture of H₂O and D₂O vapors) excited by pulse-periodic discharges with open electrodes, as well as electrodes outside the discharge tube (capacitive discharge), are presented. Radiation is studied in a spectral range of 175–350 nm. The emission characteristics of a UV radiation source based on vapors of ordinary and “heavy” water, as well as the results of optimization of brightness of radiation bands from the OH and OD radicals as functions of pressure and the composition of the He-H₂O and He-D₂O mixtures, are reported.