Creation of highly excited H{sub 2} molecules in a hydrogen flux penetrative through cesium-hydrogen discharge
- Laboratoire de Physique des Millieux Ionises, Ecole Polytechnique, 91128, Palaiseau (France)
- A. F. Ioffe Physical-Technical Institute, 26 Polytechnicheskaya, St. Petersburg, 194021 (Russian Federation)
There is a considerable interest in the creation of vibrationally excited H{sub 2} molecules because of their application to H{sup -} volume-plasma sources, plasma chemistry etc. It was shown previously that a low-voltage discharge in Cs-H{sub 2} mixture might be used as an effective source of vibrationally excited H{sub 2} molecules. In the present communication, it is shown that vibrational distribution function (VDF) of H{sub 2} molecules may be very significantly improved if vibrational excitation occurs in a moving flux of H{sub 2} molecules penetrative through the discharge.The following theoretical model is considered. Hydrogen flux flows in a flat channel and passes through two sections one after another. The first section (I) is a discharge one, where low-voltage Cs-H{sub 2} discharge occurs and vibrationally excited H{sub 2} molecules are created. In the next section (II), the excited hydrogen flows in a plane channel, which walls are unheated. Because of a large value of the mean vibrational energy of H{sub 2} molecule, very significant intensification of H{sub 2} high vibrational level population takes place in the section II. This intensification is of the order of 10{sup 3}-10{sup 4} for several vibrational levels. The increase of vibrational level population occurs due to the diffusion of vibrational quanta, by v-v exchange, up to high vibrational levels. VDF, obtained at the exit of a section II, is significantly improved for the purposes of H{sup -} generation by means of dissociative attachment.
- OSTI ID:
- 21199159
- Journal Information:
- AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 439; ISSN APCPCS; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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