The cross-section for the charge-transfer reaction of O- with O2 is determined in the relative kinetic energy range from 1 eV (threshold) to about 3 eV, using a combination of experimental and theoretical ion-swarm techniques. Reaction rate constants are measured in a helium-buffered flow-drift tube in the range 50 ≤ E/N ≤ 110 Td, where E is the DC electric field strength, N is the helium gas number density and 1 Townsend (Td) 10-17 V cm2. Velocity distributions are computed using Monte Carlo techniques for O- ions drifting in helium at E/N values in this range. These distributions and the drift-tube rate constants define the reaction cross-section at low collision energies, a region in which it has been difficult to make reliable ion-beam measurements.
|Number of pages||12|
|Journal||International Journal of Mass Spectrometry and Ion Physics|
|State||Published - Jun 1980|
Bibliographical noteFunding Information:
This research was supported in part by the Advanced Research Projects Agency under Contract NOOO-14-76-CO098 and the Defense Nuclear Agency.