| Autor: |
G. A. Khayrallah, J. E. Bayfield |
| Rok vydání: |
1975 |
| Předmět: |
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| Zdroj: |
Physical Review A. 12:869-875 |
| ISSN: |
0556-2791 |
| DOI: |
10.1103/physreva.12.869 |
| Popis: |
Two experimental tests of the $^{4}\mathrm{He}^{++}$-$\mathrm{H}(1s)$ close-coupling collision calculations were performed with a highly mass-resolved $^{4}\mathrm{He}^{++}$ incident ion beam and an atomic hydrogen scattering target. The total single-electron-transfer cross section ${\ensuremath{\sigma}}_{21}(\mathrm{H})$ was measured for $^{4}\mathrm{He}^{++}$ energies between 7 and 144 keV, with the results in better agreement with molecular-state calculations than with theory employing atomic states. Above 25 keV this cross section is 50% above values obtained by Shah and Gilbody for incident $^{3}\mathrm{He}^{++}$ with the same collision velocity. Also measured was the cross section ${\ensuremath{\sigma}}_{21}^{*}(\mathrm{H})$ for single-electron transfer into the $2s$ state of ${\mathrm{He}}^{+}$ using an ion-photon time-coincidence technique over the $^{4}\mathrm{He}^{++}$ energy range 7 to 70 keV. These data differ with the corresponding $^{3}\mathrm{He}^{++}$-$\mathrm{H}(1s)$ data of Shah and Gilbody at the higher energies. For ${\ensuremath{\sigma}}_{21}^{*}(\mathrm{H})$, the observed energy dependence as well as the magnitude at the lower energies are in marked disagreement with all close-coupling results. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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