Formation and behavior of excited cations

The electron bombardment of molecules generally gives rise to ions in more than one electronic state. The ion beam composition with respect to the electronic states can be determined by studying the attenuation of the beam as a function of the pressure of a suitable gas. In this way, the composition of B⁺, F⁺, C⁺, H₂O⁺ and H₃O⁺ ion beams was determined. The difference between the reactive behavior of the ion beam in the ground and the first excited state with simple targets such as molecular hydrogen and its stable isotopic variants and some of the factors which determine the amount of excited state produced were examined.