Bg. Lindsay et al., ABSOLUTE PARTIAL CROSS-SECTIONS FOR ELECTRON-IMPACT IONIZATION OF SO2FROM THRESHOLD TO 1000 EV, J GEO R-PLA, 101(E9), 1996, pp. 21151-21156
Absolute partial cross sections for the production of SO2+, SO+, (S+ O-2(+) + SO22+), O+, and SO2+ from electron impact ionization of SO2
are reported for electron energies from threshold to 1000 eV. The prod
uct ions are analyzed using a time-of-flight mass spectrometer and det
ected with a position-sensitive detector, making it possible to demons
trate complete collection of all product ions. The overall uncertainty
in the absolute cross section values is +/-3.5% for SO2+ ions and is
slightly higher for fragment and multiply charged ions. While much of
the previously published data are in reasonable agreement with the dat
a presented here, the present O+ cross section is higher than earlier
measurements by approximately a factor of 3. The cross section for pro
duction of SO2+ has not been previously reported. The sum of the parti
al cross sections is compared to previously measured total cross secti
ons.