We describe a novel SIMION model, based on the principle of reciprocity, to simulate ion–image charge detection and demonstrate utility for Fourier transform ion cyclotron resonance mass spectrometry. The model accommodates arbitrary electrode geometry, magnetic field inhomogeneity, ion-neutral collisions, and swept or single-frequency excitation, but does not account for ion–ion or ion–image charge forces. Accurate frequency-domain spectra reflect actual features of FT-ICR mass spectra including odd and even harmonic multiples of the ion cyclotron frequency, sidebands at odd and even multiples of the trapping frequency, and asymmetric sidebands at even multiples of the magnetron frequency. The model is general and could be applied to other mass analyzers including the quadrupole ion trap, time-of-flight, and orbitrap.
