Optogalvanic effect in a hollow cathode discharge: mechanism and uranium isotopic analysis
Creators
- 1. Ecole Polytechnique de Montreal (Canada)
- 2. MPB Technologies, Dorval (Canada)
Description
In this communication we show that the mechanism responsible for the optogalavanic effect in a hollow cathode discharge tube when the plasma is irradiated with a laser beam tuned on a non ionizing, allowed transition of the sputtered atoms is a global heating of the plasma. This heating results from a redistribution, via electron collisions, of the absorbed laser energy. Hence the associated laser induced ionization does not conserve the selectivity character of the irradiation. Furthermore we show that an optogalvanic spectroscopy based techniques is a promising approach to isotopic analysis of uranium. The value of the 235 isotopic abundance in natural uranium, found by this method, is in very good agreement with mass spectrometry determinations. This method appears to be much more accurate and reliable than the classical absorption or emission techniques of analysis. The calculated detection limit, in our experimental conditions, for an even uranium isotope is 106 atoms/cm3. This corresponds to a 0.00015% abundance of this isotope
Abstract (French)
Nous presentons les resultats des travaux qui ont permis de demontrer que le mecanisme responsable de l'effet optogalvanique dans les lampes a cathode creuse, lors du pompage optique sur une transition de l'espece pulverisee, est le chauffage global du plasma. Ce chauffage est du a la redistribution par collision electronique de l'energie laser absorbee. Par la suite, la production d'ions, associee au pompage optique, est non selective. Comme application de cet effet nous demontrons que la spectroscopie optogalvanique est une methode prometteuse pour le dosage isotopique de l'uranium. Les valeurs obtenues de l'abondance de l'isotope 235 dans l'uranium naturel sont en bon accord avec les determinations effectuees par spectrometrie de masse. Cette methode est beaucoup plus sensible que les methodes conventionnelles de spectroscopie d'absorption et d'emission. Pour nos conditions experimentales la limite de detection calculee d'un isotope pair d'uranium est d'environ 106 atomes/cm3, ce qui correspond a une abondance isotopique de 0.00015%Additional details
Additional titles
- Original title (French)
- Effet optogalvanique dans une decharge a cathode creuse: mecanisme et dosage isotopique de l'uranium
Publishing Information
- Journal Title
- J. Phys. (Paris), Colloq.
- Journal Issue
- no.C-7
- Series
- J. Phys. (Paris), Colloq.
- ISSN
- 0449-1947
Conference
- Title
- C.N.R.S. international colloquium on optogalvanic spectroscopy and its applications.
- Dates
- 20-24 Jun 1983.
- Place
- Aussois (France).
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 15027139
- Subject category
- S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- ACCURACY; CATHODE SPUTTERING; EXCITATION; HOLLOW CATHODES; HYPERFINE STRUCTURE; ISOTOPE RATIO; LASERS; OPTICAL PUMPING; SENSITIVITY; SPECTROSCOPY; URANIUM ISOTOPES
- Descriptors DEC
- AMPLIFIERS; CATHODES; ELECTRODES; ENERGY-LEVEL TRANSITIONS; EQUIPMENT; SPUTTERING