Collisions of kilo-electron-voltH+andHe+with molecules at small angles: Absolute differential cross sections for charge transfer

Absolute differential cross sections for charge-transfer scattering of ${\mathrm{H}}^{+}$ and ${\mathrm{He}}^{+}$ from molecules are reported over the laboratory angular range 0.02°–1.0°. Cross sections have been determined at 0.5, 1.5, and 5.0 keV for collisions of ${\mathrm{H}}^{+}$ with ${\mathrm{N}}_2$ and ${\mathrm{O}}_2$, and at 1.5 keV for collisions of ${\mathrm{H}}^{+}$ with CO, ${\mathrm{CO}}_2$, NO, and ${\mathrm{CH}}_4$, and of ${\mathrm{He}}^{+}$ with ${\mathrm{H}}_2$, ${\mathrm{N}}_2$, ${\mathrm{O}}_2$, CO, and NO. The data exhibit considerable structure over the experimental angular range. Absolute integral cross sections from 0° to 1.0° have been obtained and are compared with the published total cross sections.