Neutron detection capabilities of Water Cherenkov Detectors

Abstract In this work we show the neutron detectioncapabilities of a water Cherenkov detector(WCD). The experiments presented here were performed using a simple WCD with a single photomultiplier tube (PMT) and a 252 Cf neutron source. We compared the use of pure water and water with non contaminant additive as the detection volume. We show that fast neutronsfrom the 252 Cf source can be detected over the flux of atmospheric particles background. Our first estimation for the neutron detectionefficiency is at the level of (19)% for pure water and (44)% for the water with the additive. We also present the simulation of the response of the WCD to neutronsusing a simulated 252 Cf source. We implemented a detailed model of the WCD and of the neutron sourcespectra using Geant 4. The results of our simulations show the detailed mechanism for the detection of neutronsusing WCD and support the experimental evidences presented. Since both active volumes studied, H 2 O pure and with additive, are cheap, non-toxic and easily accessible materials, the results obtained are of interest for the development of large neutrondetectors for different applications. Of special importance are those related with space weatherphenomena as well as those for the detection of special nuclear materials. We conclude that WCD used as neutrondetectors can be a complementary tool for standard neutron monitorsbased on 3 He.