Low energy ionizing collisions between N2 and CO beam molecules and CO, N2, NO, CH4, and CO2 target molecules

Absolute total negative charge production cross sections for N2+CO, CO+N2, CO+CO, N2+NO, N2+ CH4, and N2+CO2 collisions have been measured to within about 1 eV of their respective thresholds. Mass spectrometric identification of the product ions scattered in the forward direction has been used to investigate specific reaction channels and explain characteristic structures in the total charge production cross sections in the near-threshold regions. Such structures, the most dramatic of which results from the N2+CO →NO++CN− ion pair formation reaction, tend to dominate the cross section shapes at low energies. Dissociative ionization is also shown to be important in such collisions. In fact, ’’simple’’ ionization, where one of the initial molecules simply gives up an electron, is not even an important process for some reactants in this low energy regime. The results of the cross section measurements and the mass spectrometric investigations are presented and a simple model of the collision to aid in understanding the results is discussed. Also presented are charge transfer cross sections for CO++CO, CO++CH4, and N+2+CH4 and secondary electron emission coefficients for CO molecules on a gold surface.