METHOD OF DETECTING NEUTRONS IN PRESENCE OF GAMMA-RADIATION Russian patent published in 2015 - IPC G01T3/00 

FIELD: physics.

SUBSTANCE: method of detecting neutrons in the presence of gamma-radiation with a timing measurement procedure includes measuring direct current I_γ arising in a neutron detector under the effect of gamma-radiation, wherein the operating discrimination threshold U_Dop for detecting the neutron count rate is set based on two values of the count rate of natural detector noise on the non-operating branch of the integral pulse spectrum, when on the logarithmic scale the line which joins said values - 1^st (N_SH1) - highest within the resolution of the amplification circuit, 2^nd (N_SH2) - low, selected while satisfying the condition N_SH2 ≥ 10·N_n, where N_n is the expected neutron count rate, is extrapolated on a discrimination axis, having a linear scale, and the point of intersection on the discrimination axis in the region N_SH ≤ (10^-1-10^-2)·N_n is taken as U_Dop, wherein the contribution of noise pulses in the neutron count rate N_n measured after establishing U_Dop is negligible, and the current I_γ measurement channel additionally includes automatic adjustment of high voltage values of the detector U_high1 (before automatic adjustment of the zero of the current I_γ measurement circuit), U_high2 (before measuring current I_γ) and a reference signal with automatic control of its reproducibility.

EFFECT: eliminating the effect of instability of the neutron detection channel on current measurement results while ensuring the highest possible efficiency of detectors for any gamma dose rate.

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