Patent ID: 7139350

Claim:
A method for measuring a property of material penetrated by a borehole comprising the steps of: (a) irradiating said material with a source of radiation generating a plurality pulses of neutrons of about five microseconds per pulse and at a periodic pulse repetition rate of about 10,000 to 20,000 pulses per second thereby inducing gamma radiation within said material; (b) measuring said induced radiation with a single radiation detector comprising a YAP scintillator crystal, a light responsive means coupled to said scintillator crystal, and circuitry connected to said light responsive means for processing output from said scintillator crystal, wherein said detector is operated during each of said pulses, and (c) determining said property from said measure of said induced radiation, wherein (d) said radiation detector processes and resolves up to three detected scintillations without scintillation pulse pile-up during each said neutron pulse.