Space charge effects in Fourier Transform Mass Spectrometry. I. Electrons

Extensive efforts to develop the theory of Fourier Transform Mass Spectrometry (FTMS) have led to an understanding of the qualitative aspects of the technique and to quantitative predictions which have been experimentally verified. At the same time, a number of theoretical assertions have not yet been quantitatively tested. In particular, further quantitative comparisons between theoretical and experimental peak shapes, including determinations of height, width, area, and center position could prove useful to further development of the FTMS technique. All of these peak shape parameters are affected by the number of charged particles present in the analyser cell during FTMS analysis. Quantitative comparisons of experimental values of these parameters with the predictions of theory presumes accurate knowledge of the number of charged particles present in the analyser cell during the observation of ion cyclotron decay signals.