Analysis of Data Measured with a Neutron Detector Based on a Boron-10 and Helium-3 Counter on a Source of Photoneutrons

Resumo

Data obtained on the IN-LUE photoneutron source at the Russian Academy of Sciences’ Institute for Nuclear Research are analyzed. The data are acquired using a position-sensitive neutron detector with an active ¹⁰B layer and a ³He SNM-18 counter. The efficiency of the ¹⁰B detector relative to the ³He counter ranges from 2 to 4% for different modes of accelerator operation. Waveforms of the ³He counter’s pulses are recorded using a built-in L-CARD L-783 multifunctional high speed signal processor with sampling frequencies of up to 3 MHz. The amplitude and time spectra of thermal neutrons are obtained from the waveforms using induced electromagnetic signals from the accelerator dump and neutron pulses. Using a cadmium mask with slits and a position-sensitive detector with a low (<10⁻⁷) sensitivity to electromagnetic interference and the gamma-ray background allows the spatial resolution of the¹⁰B detector to be determined and the contribution from neutrons with different energies to b estimated.