Dissociative and double photoionization of CO2 from threshold to 90 Å

Abstract

The molecular photoionization [Math], dissociative photoionization (CO + O + and C + ) and double photoionization (CO 2+ and C 2+ ) cross sections for CO 2 have been measured from their onsets down to 90 A by using various combinations of mass spectrometers (a coincidence time of-flight mass spectrometer and a magnetic mass spectrometer) and light sources (synchrotron radiation, and glow and spark discharge). It Is concluded that the one broad peak and the three shoulders In the total absorption cross section curve between 640 and 90 A are caused completely by dissociative ionization processes. Several peaks observed In the cross section curve for the total fragmentation (CO + , O + and C + ) are compared with those in the photoelectron spectrum reported for CO 2 . The accuracy of the present cross sections Is estimated to be about 10, 15 and 50 % for σ (CO 2 ) σ (CO + , O + and C + ) and σ (CO 2+ and C 2+ ), respectively.