Charge transfer of keV O⁺ ions with atomic oxygen

Abstract

Abstract. We report absolute differential cross sections for charge transfer scattering of 0.5-5 keV O+(4S) ground state and O+(2D, 2p) metastable ions by atomic oxygen at angles between 0.04 ø and 3 ø in the laboratory frame. Absolute total charge transfer cross sections, derived from these measurements, are compared with previously published data. The measurements were made using a flowing gas target, which consisted of a mixture of atomic and molecular oxygen produced by passing 02 through a microwave discharge. The atomic oxygen cross sections were obtained by appropriate subtraction of the signal due to molecular oxygen from that due to the mixture of O and 02. These data are relevant to model calculations of energetic O + precipitation into the upper atmosphere and to the diffusion of low-energy O + ions in the ionosphere.

Charge transfer cross sections for energetic neutral atom data analysis

“…The agreement between these studies is perhaps not too unexpected since, in contrast with the case of O + ‐H collisions, symmetric resonant channels are available for all O + ‐O collisions and the cross sections for ground‐ and excited‐state ions would not be expected to differ markedly. This supposition has recently been confirmed by the state‐specific study of Lindsay et al [2001], who report that the O + ( 2 D , 2 P ) excited‐state cross section is only 30% smaller than that for ground‐state ions. Given the especial challenges posed by these O + ‐O measurements, it is encouraging to see that all of the studies are in reasonable agreement; the mixed‐state data of Stebbings et al [1964] and those of Rutherford and Vroom [1974] lie between the ground‐ and excited‐state cross sections of Lindsay et al [2001] and all three studies are therefore consistent.…”

“…This supposition has recently been confirmed by the state‐specific study of Lindsay et al [2001], who report that the O + ( 2 D , 2 P ) excited‐state cross section is only 30% smaller than that for ground‐state ions. Given the especial challenges posed by these O + ‐O measurements, it is encouraging to see that all of the studies are in reasonable agreement; the mixed‐state data of Stebbings et al [1964] and those of Rutherford and Vroom [1974] lie between the ground‐ and excited‐state cross sections of Lindsay et al [2001] and all three studies are therefore consistent. The higher‐energy data of Lo et al [1971] are also consistent with the other measurements.…”

“… Lindsay et al [2001] also report angular differential cross sections and discuss the implications of their data for the determination of the O + ‐O collision frequency [ Burnside et al , 1987; Salah , 1993; Buonsanto et al , 1997].…”

Energetic neutral atoms at Mars 4. Imaging of planetary oxygen

“…However, this is not important as long as a significant scattering does not occur. Recently Lindsay et al [2001] published the differential cross sections for charge‐exchange scattering in the reaction O + + O for the energies 0.5–5 keV that is very close to the energy range 0.1–10 keV in question. As one can see in their Figure 2 the differential cross section's distributions over the entire range are highly peaked at 0°.…”

On the sensitivity of total electron content (TEC) to upper atmospheric/ionospheric parameters

“…These efforts have been reviewed by Salah (1993) up to 1993 and are still ongoing (e.g., see Buonsanto et al, 1997b;Omidvar et al, 1998;Lindsay, 2001).…”