The BC-704 scintillation screen with light readout by wavelength shifting fibers as a highly efficient neutron detector

Abstract

The aim of the work is to investigate the revised concept of a neutron detector, offered by Saint Gobain-the BC-704 scintillation screen with a light readout by Wavelength Shifting (WLS) fibers. This detector was developed as a replacement of helium tubes, due to the lack of <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> He on the world market. It is characterized by high sensitivity to gamma-rays, but the events from neutrons and gammas are well separated. Measurements with gamma and neutron sources have been performed and the results have been compared with helium-3 counter. According to American National Standards Institute (ANSI), we obtained n/γ discrimination on the level of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-10</sup> , whereas absolute neutron detection efficiency was estimated as approximately two times higher than in the case of the reference <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> He tube without the moderator. The tested detector is a sample prototype of one detector configuration of many possible, and that it can be modified to the neutron efficiency specification required.