Speaker
Description
In this work we show the neutron detection capabilities 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 additives as the detection volume, while explore different
neutron moderators and shield configurations.
We show that fast neutrons from the $^{252}$Cf source, as well as, thermal
neutrons coming from neutron moderators and exhibiting different spectral
characteristics, can be clearly detected and identified over the flux of
atmospheric particles background. Our first estimation for the neutron
detection efficiency is at the level of (19)\% for pure water and
(44)\% for the water with the additive. In this work we also present
the simulation of the response of the WCD to neutrons of different
energies, ranging for meV to GeV. To do this, a detailed model of the WCD and
of the neutron source spectra have been implemented. The results of our
simulations show the detailed mechanism for the detection of neutral
massive particles using WCD and support the experimental evidences
presented. We compared the expected results from different WCD sizes,
different active volumes and shields, and calculated the expected
efficiency for each configuration. The sensitivity of WCD obtained in our
simulations in the wide neutron energy range explored is a relevant result for
cosmic rays and space weather studies.
Being both the active volume and the additive, cheap, non-toxic and easily
accessible materials, the results obtained are of interest for the
development of large neutron detectors for different applications. Of
special importance are those related with space weather phenomena as well
as those for the detection of special nuclear materials. We conclude that
WCD used as neutron detectors can be a complementary tool for standard
neutron monitors based on He$^3$.
