A simple cosmic-ray veto shield for low-rate neutron measurements

A cosmic-ray veto shield for the University of Notre Dame neutron wall has been constructed in order to carry out low-rate neutron time-of-flight (TOF) measurements. The veto detector employs plastic scintillator embedded with wavelength-shifting fibers and is read out by a versatile coupling to standard photomultiplier tubes (PMTs). This veto shield is effective at reducing the muon background by about one order of magnitude and therefore increases the sensitivity for experiments with low neutron yields. The 26Mg(3He,n)28Si reaction was used as a testbed for the veto.