Dissociative Attachment in CO and Formation of Cminus;

摘要

The negative ions Ominus;and Cminus;produced by dissociative attachment of electrons in CO are measured using a quadrupole mass spectrometer. A trochoidal monochromator is used to give an electron energy distribution of about 0.07 eV. Within this resolution, the Ominus;ion current exhibits a vertical onset at threshold and structure is observed at higher energies. The cross section of the production of Cminus;shows an onset at 10.20thinsp;plusmn;thinsp;0.04 eV, a peak at 10.4 eV, and a second peat at 10.9 eV. The cross section at the first Cminus;peak is found to be smaller than the peak cross section for Ominus;production by a factor of 3300thinsp;plusmn;thinsp;20percnt;. Using the previously determined value for the Ominus;cross section (2thinsp;times;thinsp;10minus;19cm2) the peak cross section for Cminus;formation is about 6thinsp;times;thinsp;10minus;23cm2.