Use of neutron-capture plastic fibers for nondestructive assay

Conference · Thu Dec 31 04:00:00 EST 1998

OSTI ID:319740

Heger, A S; Grazioso, R F; Mayo, D R; Ensslin, N; Miller, M C; Huang, H Y; Russo, P A

Neutron-capture plastic fibers can be used as a nondestructive assay tool. The detectors consist of an active region assembled from ribbons of boron-({sup 10}B) loaded optical fibers. The mixture of the moderator and thermal neutron absorber in the fiber yields a detector with high efficiency ({var_epsilon}) and a short die-away time ({tau}). 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 {sup 3}He detectors. Experiments with single fibers of diameters 0.25, 0.50, and 1.00 mm test their ability to distinguish between the signals generated from neutron interactions and those from gamma rays. These results are compared with those obtained from simulation analyses for the same purpose. Light output and attenuation, neutron detection efficiency, and the signal-to-noise ratios of these fibers have also been investigated. The experimental results for light attenuation and neutron detection efficiency are consistent with the values obtained from simulation studies. A comparison of the performance of various configurations of the plastic scintillating fibers with that of other neutron-capture devices such as {sup 3}He detectors is also discussed.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 319740
• Report Number(s): LA-UR--98-3054; CONF-980733--; ON: DE99001846
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
BORON 10
COMPARATIVE EVALUATIONS
FISSILE MATERIALS
NEUTRON DETECTORS
NONDESTRUCTIVE ANALYSIS
OPTICAL FIBERS
PERFORMANCE
PLASTIC SCINTILLATION DETECTORS