Glass Scintillator for Neutron Detection

Abstract

A glass scintillator which can be used as one of the main components of a slow‐neutron time‐of‐flight spectrometer has been developed. This sodium aluminoborate glass containing 73 mole % B2O3 and 8.0 mole % Ce was melted under highly reducing conditions in a series of cerium‐activated very high boron‐containing glasses. This glass is water white with very high light transmittance for wave lengths greater than 3800 a. u. It has a neutron‐detection efficiency which is 25 to 30% greater than any other known glass scintillator in the energy range 102 to 104 e.v. and is considerably better than any other type of detector. It was found that the neutron pulse height increases with increasing cerium content up to a maximum and then decreases with further increases in the cerium content. The molar content of cerium required to obtain a maximum pulse height for each B2O3 concentration increases linearly with the increase in the B2O3 content. However, the maximum pulse height decreases gradually with the B2O3 content from 17.0 arbitrary units at 54.5 mole % to 6.7 at 73.4 mole %. This lower pulse height is still considerably above the photomultiplier noise at room temperature.