INELASTIC COLLISIONS OF RARE GAS IONS AND EXCITED ATOMS WITH NEUTRAL MOLECULES
A high-resolution mass spectrometer was used to measure the inelastic cross sections for the ion-molecule reactions Ar/sup +/ + H/sub 2/ yields ArH/ sup +/ + H and Ar/sup +/ + D/sub 2/ yields ArD/sup +/ + D in the energy range 60 to 215 ev. The cross sections were found to be in the ratio of approximates 2: 1 with the first reaction exhibiting the larger cross section. The cross sections were found to vary inversely with the 3/2 power of the energy in the range 60 to 155 ev, rapidly leveling off to zero energy dependence beyond 155 ev. The ion source used for the production of positive ions was also employed for the production of He and Ar metastable atoms for studying the Penning ionization processes of the type A/sup */ + XY yields X/sup +/ + Y + A + e + k.e. Here A/ sup */ is the metastable atom involved in the collision with a molecule, XY. The target gases methane, ethane, O, and N were used. Several ion fragments resulted from the inelastic collisions of methane and ethane with the metastable atoms. The resulting mass spectra of such fragment ions were compared to the spectra obtained from conventional electron bombardment studies. The measurements have demonstrated, for the first time, that fragment ions are formed in a Penning ionization process, provided the metastable atom has sufficient energy. These ions have been identified by mass spectroscopy, and significant differences in their relative abundances, as compared with those observed for electron impact, have been observed. Information relative to the upper limits for the appearance potentials of these ions and the mode of fragmentation was obtained. (M.P.G.)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-18-009042
- OSTI ID:
- 4102756
- Resource Relation:
- Other Information: Thesis. Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
Chemi-ionization in collisions of metastable argon with metastable krypton
Excitation of continuum radiation in collisions of (1) electrons and (2) metastable argon atoms with H/sub 2/ and D/sub 2/