The importance of the time-lag parameter in a laser/time-of-flight mass spectrometer

Abstract

The time-lag delay has been shown to be an important experimental parameter in the measurement of fragmentation patterns in multiphoton ionization spectra obtained using a time-of-flight mass spectrometer. Experimental data indicate that ions formed by multiphoton ionization acquire greater translational energies and are lost more rapidly from the ionization region than those formed by electron-impact ionization. Time-lag focussing does produce improved resolution in multiphoton ionization, but it is only effective for those ions which have not moved out of the draw-out volume. Utilization of a low-level electron beam trap has been found to be ineffective in retarding ion loss in multiphoton ionization experiments.