Enhancing neutron detection capabilities of a water Cherenkov detector

Abstract

In this work we show the neutron detection capabilities of a water Cherenkov detector (WCD) using pure water, as well as an aqueous solution of sodium chloride as the detection volume. The experiments were performed using a WCD with a single photomultiplier tube (PMT), and a 252Cf neutron source. We show that fast neutrons from a 252Cf source directly impinging the detector can be clearly detected and identified over the natural radiation background. We also present results from numerical simulations that describe the response of the WCD to neutrons of different energies. To do this, a detailed model for the WCD and of the neutron source spectra have been implemented. The implemented simulation code takes into account the interaction processes involved in the detection of neutrons using WCD, and support the experimental evidence introduced in this work. Being both the active volumes analyzed in this work (pure water) and the additive (sodium chloride), cheap, non-toxic and easily accessible materials, the results obtained are of interest for the development of large neutron detectors for different applications. Of particular importance are the detection of special nuclear materials, as well as those applications related with space weather phenomena. We conclude that WCD used as neutron detectors could be a replace or a complementary tool for standard neutron monitors based on 3He.