Studies of Ionization Efficiency. Part IV. The Electron Spectra of Some Simple Molecules

The second differential ionization efficiency curves for a number of simple molecule‐ions have been recorded using a new technique of measurement. A close correlation can be drawn between the results and spectroscopic data, confirming in most respects the interpretation of ionization efficiencies made in Part III. It proves possible to detect the presence of upper ionic states at energies corresponding to extreme ultraviolet radiation. The factors which affect line shape in optical spectra are shown to apply also to the second differential ionization efficiency curves, which are termed electron spectra. It is shown that the ionization efficiency curves for fragment ions can also be interpreted in a similar manner, and the types of electron spectra to be expected for different kinds of dissociation processes are discussed.