B. E. Krylov

Channels of energy transfer to atomic nitrogen in excited argon-nitrogen mixtures

The vacuum ultraviolet (VUV) and ultraviolet (UV) emissions of gaseous mixtures of argon with a small amount of nitrogen were investigated in the afterglow of a pulsed transverse discharge. The time dependences of the intensity of the VUV argon continuum at 126.0 nm, the UV nitrogen molecular band at 337.0 nm, and the VUV nitrogen atomic lines at 149.47 and 174.52 nm were analysed in the total pressure range 150–600 hPa and the range 0.125–1.5 hPa of the admixture concentrations. The results show that all these emissions have a common source of excitation energy, namely the atomic metastable 3P2 state of argon. However, atomic nitrogen also receives energy from the atomic 3P1 state of argon and from the excited Ar2* (1u) molecules.

VUV emission spectra from binary rare gas mixtures near the resonance lines of Xe I and Kr I

Emission spectra of Xe–X (X = He, Ne, Ar and Kr) and of Kr–Y (Y = He, Ne and Ar) mixtures with low concentrations of the heavier gases (0.1–1%) and moderate total pressures (50–200 hPa) have been recorded near each of the two resonance lines of Xe and Kr in DC glow capillary discharges. The recorded intense emissions have narrow spectral profiles with FWHM of about 0.1 nm. The profiles are very similar in shape to profiles of known high resolution absorption spectra recorded at comparable gas pressures. A tentative identification of the emission structures is given, which involves transitions in heteronuclear molecules and quasimolecules between weakly-bound states.

VUV spectra of krypton-xenon mixtures in a cooled DC-excited discharge

An experimental study was made of VUV spectra of a gas-discharge krypton plasma with a xenon impurity. The mixture pressure, the xenon impurity concentration, and the current were varied in ranges of 40–1000 hPa, 0.001–1%, and 10–50 mA, respectively. The heteronuclear XeKr dimers were shown to play a crucial role in the quenching of excitation energy of krypton dimers. The mechanism of transformation of the energy of excited krypton dimers in a low-temperature plasma of a binary krypton-xenon mixture is discussed.

Parameters of VUV radiation from a DC capillary discharge in a mixture of krypton with xenon

This paper describes the technique and the results of measurement of the power and geometry of the VUV radiation beam from a dc capillary discharge in a mixture of krypton and xenon. The angular divergence of narrowband VUV radiation of the heteronuclear KrXe* molecule is shown to be narrower as compared to that of the discharge radiation in the range 200–1000 nm. The power of VUV radiation from a discharge tube 80 cm long is found to exceed 10 mW.

Vacuum ultraviolet spectra of heteronuclear dimers of inert gases in a direct-current discharge

The emission bands appearing near the resonance lines of Kr and Xe in the spectra of the gas-discharge plasma of binary Xe-X and Kr-Y mixtures (X is He, Ne, Ar, or Kr; Y is He, Ne, or Ar) are experimentally studied. It is concluded that the emission bands investigated are related to electronic transitions in hetero-nuclear dimers. The mechanisms of formation of the spectra under study are analyzed.

Amplification of λ ~147-nm radiation from discharge in heavy inert gases

The result are presented on experimental study of VUV spectra of double and triple mixtures of argon, krypton and xenon in dc and barrier discharges. Region of 120 - 200 nm was studied that corresponds to the transitions between dimer lowest excited states and the weakly bound ground states 1u, 0+u yields 0+g. The pressure in capillary dc discharge was 100 - 1000 hPa and discharge current was 20 - 50 mA. The experiment with 10, 20 and 40 cm tubes corresponded a gain 0.1 cm-1 at (lambda) approximately 147 nm.

Stimulated emission of inert gas mixtures in the VUV range

Amplification properties of continuous VUV emission of cooled discharge in mixtures of heavy inert gases are studied experimentally. The discharge current is 10–50 mA, the pressure is 100 GPa. Results pointing to amplification near the resonance line of xenon λ=146.96 nm are obtained. The amplification coefficient is measured to be κ=0.1 cm−1. The problem of radiation outcoupling from the active medium remains to be solved for practical implementation of a VUV laser.

Characteristics of a glow-discharge krypton lamp in the vacuum ultraviolet

The spectral and energy characteristics of a compact krypton glow-discharge lamp used as the ionization source in analytical devices have been investigated. The emission spectrum of the lamp in the 115–200 nm VUV region has been studied, the flux of VUV emission has been measured, and data concerning the intensity ratio of the 116.49 and 123.58 nm resonance lines of krypton emitted by the lamp have been obtained.

A study of atomic and molecular energy transfer channels in Kr-Xe gas mixtures excited with radio frequency discharges

Simultaneous observations of the vacuum ultraviolet (VUV) and visible-near-IR emission from radio frequency discharges in gaseous Kr with small (<0.1%) Xe admixture concentrations were conducted in the pressure range 80-400 hPa. The spectra were used for investigation of energy transfer from the lowest excited states of both atomic krypton and krypton molecules to the ground state xenon atoms. The VUV emission spectra allowed us to obtain a value of 3.9×107×PXe hPa-1 s-1 for the energy transfer rate from the 1u state of Kr2* molecules and a rate of 1.7×106×PXe hPa-1 s-1 for the energy transfer rate from the system of the four lowest Kr excited states to Xe ground state atoms. A value of 1.6×106×PXe hPa-1 s-1 was independently obtained for this atom-to-atom energy transfer channel based on our observations of IR emission.

The intense VUV narrow band emission from an inert gas mixture discharge

Theoretical and experimental studies of low temperature plasmas of inert gas mixtures show a very high efficiency for energy transfer from broad vacuum ultravio let (VUV) continua to narrow spectra. The process of energy transfer can not be explained as an ordinary particle collision mechanism. Narrow band light amplification in plasmas of inert gas mixtures is discussed as a possible process of energy transfer.