Effect of the spatial resolution function of the spectrometer on the analysis of multi-exponential beam-foil decay curves

The effect of the spatial resolution function of the spectrometer on beam-foil lifetime measurements is studied. Intensity curves obtained by convolution of the measured spatial resolution function and a sum of exponentials are compared with measured decay curves. Optimum spatial resolution functions are discussed and results of the analysis of decay curves obtained using different beam lengths viewed by the spectrometer are given, for two transitions presenting strong cascading: 3s3d3D-3s4f3F0 in S V (568 A) and 3d3D-4f2F0 in S VI (465 A). (Auth.)