Patent ID: 7999220

Claim:
A borehole instrument comprising a neutron generator axially spaced from a gamma ray detector assembly, said assembly comprising: a LaBr3 scintillation crystal; and a digital spectrometer cooperating with said LaBr 3 scintillation crystal and configured to measure pulses from said scintillation crystal, digitally filter said pulses from said scintillation crystal, digitally inspect the filtered pulses to detect pile-up pulses, periodically forming an estimate of an average ratio of said measured pulses per non-pile-up pulse, and reject said pile-up pulses by combining said measured pulses with said ratio; wherein; said neutron generator emits a plurality of bursts of neutrons the duration of each burst of said plurality of bursts being about 30 microseconds and said plurality of bursts being emitted at a repetition rate of about 5 KHz; and said detector assembly is operated during said bursts.