A method for high resolution amplitude measurements in presence of noise and pile-up fluctuations

The problem of achieving the highest resolution in the amplitude measurement of pulses randomly spaced in time is considered, taking into account both noise and pile-up fluctuations due to slow signal tails. Signals composed by a pulse of finite duration and a long tail, are considered: a measuring technique is introduced, based on a linear combination of sampling measurements on the pulse. It is shown that, by a suitable choice of weights, optimum compromise between noise and tail pile-up effects can be reached, allowing good resolution at high counting rates. Results of calculations are given for the well known finite width cusp pulse and exponential tails.