Neutron detection using a water Cherenkov detector with pure water and a single PMT

Abstract We present the performance of a novel neutrondetector based on a water Cherenkov detector(WCD) employing pure water and a single photomultiplier tube (PMT). The experiments presented in this work were performed using 241 AmBe and 252 Cf neutronsources in different neutron moderatorand shielding configurations. We show that fast neutronsfrom the 241 AmBe and 241 Cf sources, as well as thermal neutronsfrom a neutron moderator, despite having different spectral characteristics, produce essentially the same pulse histogram shape. This characteristic pulse-height histogram shapes are recorded as a clear signature of neutronswith energies lower than ≃ 11 MeV . This is verified in different experimental conditions. Our estimation of the neutron detectionefficiency is at the level of (15±5)%, for fast neutrons. Since water is the material employed as active volume, the results of this study are of interest for the construction of low cost and large active volume neutrondetectors for various applications. Of special importance are those related with space weatherphenomena monitoring as well as those for the detection of fissile special nuclear material, including uranium or plutonium.