Absolute partial cross sections for electron-impact ionization of CF4 fromthreshold to 1000 eV

Absolute partial cross sections for electron-impact ionization of CF4 are r eported for electron energies from threshold to 1000 eV. The product ions a re mass-analysed using a time-of-flight mass spectrometer and detected with a position-sensitive detector whose output demonstrates that ail product i ons are collected with equal efficiency irrespective of their initial kinet ic energies. Data are presented for the production of CF3+, CF2+, (CF+ + CF 32+), C+, F+ and CF22+ and for the total cross section which is obtained as the sum of these partial cross sections. The overall uncertainties in the absolute cross section values are +/-5% to +/-8%. Data are also presented f or formation of (CF+, F+) and (CF2+, F+) ion pairs. Comparison is made with prior experiments and calculations.