Energy-transfer processes in neon-hydrogen mixtures excited by electron beams -: art. no. 234311

Energy- and charge-transfer processes in neon-hydrogen mixtures (500-1400 hPa neon and 0.001-3 hPa hydrogen partial pressures) excited by a pulsed low-energy (similar to 10 keV) electron beam were investigated using time-resolved spectroscopy. Time spectra of the hydrogen Lyman-alpha line, neon excimer emission (second continuum), and neon atomic lines (3p-3s transitions) were recorded. The time-integrated intensity of the Lyman-alpha emission was measured for the same range of gas mixtures. It is shown that direct energy transfer from Ne-2(*) excimers and neon atoms in the four lowest excited states as well as recombination of H-3(+) ions are the main channels populating atomic hydrogen in the n=2 state. A rate constant of (4.2 +/- 1.4)x10(-11) cm(3) s(-1) was obtained for the charge transfer from Ne-2(+) ions to molecular hydrogen. A lower limit for the depopulation rate constant of Ne-2(*) excimers by molecular hydrogen (combination of energy transfer and ionization) was found to be 1.0x10(-10) cm(3) s(-1). (c) 2005 American Institute of Physics.