Thermal neutron imaging with CsBr storage phosphors

The storage phosphor material CsBr:Eu2+ has been investigated for use in thermal neutron imaging. CsBr:Eu2+ imaging plates were prepared in a polycrystalline form by cold pressing starting powders. These as-prepared materials show only small photostimulated luminescence intensity under thermal neutron irradiation, but the luminescence intensity can be increased by incorporating separate neutron converters, in the form of lithium, boron or gadolinium containing compounds. An imaging plate containing 5% 10B2O3 as a neutron converter has 50% the photostimulated luminescence intensity of a commercial Fuji neutron imaging plate. Thermal neutron imaging was shown to be possible with the CsBr:Eu2+-based imaging plates, and the differences in thermal neutron and X-ray images were clearly observed.