Feasibility of using boron-loaded plastic fibers for neutron detection

The results from simulations and laboratory experiments with boron-loaded p lastic scintillating fibers as a nondestructive assay (NDA) tool are presen ted. Single and multi-clad fibers in three diameters of 0.25, 0.5, and 1 mm were examined for their application in neutron coincidence counting. For t his application, the simulation results show that various configurations of boron-loaded plastic scintillating fibers have a die-away time (tau) of 12 mu s with an efficiency (epsilon) of 50%. For a comparable efficiency, He- 3 proportional tubes have a typical die-away time of 50 mu s. The shortened die-away time can reduce the relative error for measurement of similar sam ples by up to 50%. Plastic scintillating fibers (PSF) also offer flexible c onfigurations with the potential to discriminate between signals from gamma -ray and neutron events. Quantitative calculations and experiments have been conducted to determine the light output, evaluate the noise, quantify light attenuation, and deter mine neutron detection efficiency. Current experimental data support the an alytical results that boron-loaded plastic fibers can detect thermal neutro ns. (C) 1999 Published by Elsevier Science B.V. All rights reserved.