Charge transfer in collisions between diatomic molecular ions and atomic hydrogen using merged beams

• Published in: Physical review. A, Atomic, molecular, and optical physics Vol. 84; no. 6
• Main Authors: Andrianarijaona, V. M., Draganic, I. N., Havener, C. C., Seely, D. G.
• Format: Journal Article
• Language: English
• Published: United States 15-12-2011
• Subjects: ATOMIC AND MOLECULAR PHYSICS; CARBON IONS; CARBON MONOXIDE; CROSS SECTIONS; DEUTERIUM IONS; ELECTRONS; EV RANGE; EXCITED STATES; HYDROGEN; HYDROGEN IONS 2 PLUS; ION-ATOM COLLISIONS; KEV RANGE; MOLECULAR IONS; NEON IONS; NITROGEN IONS; Q-VALUE; SILICON IONS; VIBRATIONAL STATES
• ISSN: 1050-2947; 1094-1622
• DOI: 10.1103/PHYSREVA.84.062716

A merged-beam technique is used to measure charge transfer (CT) cross sections for the (O{sub 2}{sup +},D) and (CO{sup +},D) systems over a wide range of collision energy from 20 eV/u to 2 keV/u. At the higher energies where the collision is rovibrationally frozen and the differences in the Q values of the CT process can be neglected, the cross sections all converge to (7.5{+-}0.5)x10{sup -16} cm{sup 2} at 2 keV/u and are consistent with a rovibrational frozen (H{sub 2}{sup +},H) calculation. Toward lower velocities, (O{sub 2}{sup +},D) and (CO{sup +},D) have consistently similar cross sections but diverge below 60 eV/u. In contrast, previously reported merged-beam measurements for (D{sub 2}{sup +},H), a system with fewer electrons on the molecular core, no electronic excited states, and relatively fewer charge transfer channels, shows a decreasing cross section toward lower energies. These different trends are compared to previous merged-beam measurements of charge transfer with H for several atomic 4+ ions (Si{sup 4+}, Ne{sup 4+}, N{sup 4+}, and C{sup 4+}) which have a variety of electrons on the core.