Multidetector gamma-neutron spectrometer and results of its modeling

Purpose. Development and study of real-time neutron radiation spectrometers with an energy range from thermal to fast neutrons.Methods. The following methods are used in the work: mathematical modeling, experimental research methods, circuit and design engineering.Results. The scientific basis for a new method of neutron radiation spectrometry with an arbitrary energy spectrum shape in the energy range from 0.001 eV to 20 MeV with the reconstruction of the measured flux spectrum based on the responses of several detectors with different spectral characteristics using a neural network trained on a sample of over 1000 spectrums of various shapes has been developed.A mathematical model of a neutron spectrometer has been developed and its study has been carried out with various combinations of detectors. An optimal combination of detectors/measuring channels has been determined, providing a minimum error in spectrum reconstruction averaged over all spectra of the training sample (~3%) with a minimum number of detectors/measuring channels used.The structure and mathematical support for an automated test and verification complex for calibrating and verifying a neutron spectrometer have been developed.A prototype of a gamma-neutron spectrometer-dosimeter with secondary processing of information received from the detection unit on a PC has been developed and manufactured. Its measuring channels have been adjusted for the radiation background of radon and its decay products and on a neutron setup with a plutonium-beryllium neutron source at the Research Institute of Nuclear Physics of Moscow State University.The operability of the detection unit at an altitude of 20 km has been proven, graphs of the dependence of the count rate of all measuring channels on the altitude have been obtained.Conclusion: The conducted experimental studies of the prototype of the multi-detector gamma-neutron spectrometerdosimeter confirmed the effectiveness of the adopted concept and the validity of the underlying theoretical principles justifying the development of the industrial prototype.