Kinetic-energy Distributions of Positive and Negative Ions in Townsend Discharges in Oxygen
MVVS. Rao, Richard J. Van Brunt, James K. Olthoff
Translational flux-energy distributions of positive and negative ions have been measured at high electric field-to-gas density ratios (E/N) up to 40 x 10-18 V m2 (40 kTd) in diffuse, parallel-plate Townsend discharges in oxygen using an ion energy analyzer-mass spectrometer. The O2+ ion is the most abundant ion detected in the discharge, and exhibits Maxwellian energy distributions for E/N < 20 x 10 -18 V m2, which is consistent with predictions based upon the assumption that resonant symmetric charge exchange is the dominant ion-molecule collision process. The less abundant ions, O+, O2-, and O-, exhibit non-Mawellian ion kinetic energy distributions at nearly all E/N, indicative of multiple ion-molecule reactions affecting the ion transport. Mean energies are obtained for each ion as a function of E/N from analysis of the energy distributions, and symmetric charge-exchange cross sections are calculated from the data where appropriate.
Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)
, Van Brunt, R.
and Olthoff, J.
Kinetic-energy Distributions of Positive and Negative Ions in Townsend Discharges in Oxygen, Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=6288
(Accessed May 29, 2023)