https://doi.org/10.1351/goldbook.09416
Full width at half maximum of the time distribution of the pulse of ions generated by a beam chopper and, optionally, the use of beam bunching in secondary ion mass spectrometry.
Note: The pulse width is usually measured using the \(\ce{H+}\) ion. The velocity of \(\ce{H+}\) ions, for a given extraction field, is larger than that of other ions. The width in time of the \(\ce{H+}\) pulse thus provides a more reliable value for the width of the extraction pulse.