Variation of relative ion abundances with accelerator potential in the mass spectrometer: The importance of source penetration

Calculations have been carried out, using the Quasi-Equilibrium Theory of Mass Spectra to show that a decrease in penetration of the accelerating field intol the ion source of a mass spectrometer may significantly increase the number of primary daughter ions [A]⁺ produced from a molecular ion [M]⁺ in the source. The calculations show that this effect appears to be more important than the decay of [M]⁺ between source and collector in implementing an increase in [A]⁺/[M]⁺ at the collector with decreasing accelerator potential.