The optimization of the neutron sensitivity of image plates
Abstract
Image plates containing varying concentrations of the neutron converter Gd 2O 3 and the storage phosphor BaFBr:Eu 2+ have been prepared. Their neutron sensitivity was measured for a neutron wavelength of 3 Å and compared with a new model, which is in good agreement with the measured data, showing that the sensitivity, which is the photostimulated light output per irradiated neutron, of image plates is always higher if the neutron irradiation and the readout are done from the same side. In this case an optimum in sensitivity can be obtained for volume fractions of Gd 2O 3 between 20% and 30% of the total volume of storage phosphor and converter in the material. In the case of neutron irradiation and readout from opposite sides the volume fraction of Gd 2O 3 should be varied reciprocally with the thickness d of the phosphor layer in order to obtain a maximum of sensitivity. The experimental results and the model indicate that the maximum sensitivity is lower by a factor between 2 and 4 compared with the readout from the same side. The relation between sensitivity and detective quantum efficiency is discussed.
- Publication:
-
Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- February 1997
- DOI:
- 10.1016/S0168-9002(96)00865-0
- Bibcode:
- 1997NIMPA.384..457T