Abstract: A process for identifying and rejecting pile-up pulses in a system is provided. Preferably, the process is applied to mine detection where time is at a premium. A thermal neutron activator sensor (TNA) trails a mine-detecting vehicle and is dwells over the coordinates of a target of interest for a short a time as possible. The TNA interrogates the object with slow neutrons, the required time being brief due to the use of a strong source coupled with a the process for analyzing the resultant high number and rate of pulses and rejecting piled-up pulses. Specifically, low energy pulses are removed and the remaining pulse is analyzed for its shape in comparison to the known shape of a non-piled-up pulse. The pulse is integrated using a gated integrator between a designated portion the pulse and for the whole pulse. For a normal pulse, the difference between the two integrations produces a repeatable baseline which is zeroed out to a null difference.