The fragmentation of CH4+ ions from photoionization between 12 and 40 eV

Abstract

The fragmentation of the methane ion has been measured as a function of ion internal energy in the range 12–40 eV using the fixed wavelength photoelectron photoion coincidence (PEPICO) technique, with He Iα and He IIα light. We confirm that the fragmentation of methane ions in the A state is not well represented by statistical calculations. In the satellite states between the A state and 33 eV, the ion breaks into small fragments; in satellite states above 33 eV the fragmentation is related to the behaviour of doubly-charged methane.