USE OF NEUTRON-CAPTURE PLASTIC FIBERS FOR NONDESTRUCTIVE ASSAY

Year
1998
Author(s)
Norbert Ensslin - Los Alamos National Laboratory
Phyllis Russo - Los Alamos National Laboratory
H.Y. Huang - Los Alamos National Laboratory
Douglas R. Mayo - Los Alamos National Laboratory
A. Sharif Heger - Los Alamos National Laboratory
Ron F. Grazioso - Los Alamos National Laboratory
Abstract
Neutron-capture plastic fibers can be used as a nondestructive assay tool. The detectors consist of an active region assembled from ribbons of boron-(10B) loaded optical fibers. The mixture of the moderator and thermal neutron absorber in the fiber yields a detector with high efficiency (e) and a short die-away time (t). The deposited energy of the resultant charged particles is converted to light that is collected by photomultiplier tubes mounted at both ends of the fiber. Thermal neutron coincidence counters (TNCC) made of these fibers can serve to verify fissile materials generated from the nuclear fuel cycle. This type of detector may extend the range of materials now accessible to assay by 3He detectors.