Absolute partial cross sections for electron-impact ionization of CO from threshold to 1000 eV

Absolute partial cross sections for electron-impact ionization of CO are reported far electron energies from threshold to 1000 eV. The product ions are mass analysed using a time-of-flight mass spectrometer and detected with a position-sensitive detector whose output unequivocally demonstrates that the various product ions are collected with equal efficiency irrespective of their initial kinetic energies. Data are presented for the production of CO+, C+, O+ and CO2+, and for the total cross section which is obtained as the sum of these partial cross sections. The overall uncertainty in the absolute cross section values is +/-5% for singly charged parent ions and +/-6% for fragment ions. Comparison is made with prior experiments and calculations.