Fast-Neutron Background at the Baksan Underground Scintillation Telescope

The search for neutrino signals from gravitational core collapses in the Milky Way is one of the main lines of research at the Baksan Underground Scintillation Telescope (BUST). Neutrons generated by cosmic-ray muons produce a considerable background in such experiments. The contribution from the elastic scattering of fast neutrons off protons to the overall single-event background rate measured in the inner detector planes is estimated via neutron activation analysis. The resulting value of the fast-neutron flux agrees with one based on the results from FLUKA modeling for the depth of the BUST detector. The same technique can be used to estimate the neutron background in similar experiments focused on rare events.