Thermal neutron detection with the lithium borate scintillator

Single crystals of ⁶Li¹⁵⁸Gd(¹¹B ₃O)₃ were grown, then powdered and mixed with powdered Schott glass and epoxy. The dough was solidified in a Teflon mold to a scintillator foil of 3 mm thickness and size 50 mm×50 mm. By attaching the ⁶Li borate foil to a conventional RCA photo multiplier (PM) and to a position sensitive Hamamatsu PM the properties as a scintillator for neutron detection were investigated with neutrons, and rays of high energy betas and gammas. The neutron absorption probability is sufficient large (36% for 0.1 nm wave length neutrons). Practically all neutron events yield sufficiently large pulses. The averaged neutron pulse is 4.8 times larger than that of a ⁶Li glass and 0.55 times smaller than that of a ⁶Li iodide. The photon energy equivalent to an average neutron pulse is 2.5 MeV (for ⁶Li glass and ⁶Li iodide the energies are 1.5 and 2.4 MeV, respectively). The spatial resolution obtained with the 45 mm×55 mm Hamamatsu PM is 0.54 mm FWHM