Sequential mass spectrometry III. Ions and fragments from carbon dioxide and disulphide

Electron collisions with slow CX2+ (CO2 or CS2) ions trapped in the electron beam which produces them gave CX22+, CX+, C+, and X2+ and X+, although this last ion was also produced from X atoms formed by dissociation of the CX2 molecule on the electron-beam filament. The direct, double ionization potential of CS2 to CS22+ was also observed, for the first time in a mass spectrometer, at 255 ± 03 eV, and the corresponding double ionization potential for CO2 was confirmed at 363 ± 05 eV. The production of S2+ from CS2 was observed, for the first time, at 182 ± 09 eV in agreement with the value expected from the ionization potential of S2 at 108 ± 03 eV. Relative transition probabilities are given for the 19 processes observed.