Abstract
The yield cross sections , , and for production of fast and ions and H atoms resulting from the ionization and dissociation of fast molecules in single collisions with gas molecules have been measured in the 6- to 120-keV energy range (collision velocity 0.7 to 3.2× cm/sec). The neutral primary beam contained a fraction of H atoms which was determined by proportional counter analysis. Secondary particles produced by the H atoms in the primary beam were determined in separate H beam experiments and subtracted from the composite (H,) neutral beam data to yield the production of secondaries due to primaries alone. Cross section increases monatonically from 0.5 to 2.0 in the energy range 6 to 120 keV while increases from 0.28 at 7.5 keV to a maximum of 0.70 at 50 keV. Cross section , measured only at 10 keV, was found to have an approximate value of 2.5 based on an assumed shape of the H atom angular distribution at small angles. The results are compared with data on a number of collision processes in the same velocity range involving various species of hydrogen ions and H atoms incident on gas molecules.
- Received 9 January 1964
DOI:https://doi.org/10.1103/PhysRev.134.A1226
©1964 American Physical Society