Development of Cerium Fluoride Nanocomposites for Neutron Capture Measurements

Year
2008
Author(s)
S. Stange - Los Alamos National Laboratory
E.A. McKigney - Los Alamos National Laboratory
A. Couture - Los Alamos National Laboratory
L. Jacobsohn - Los Alamos National Laboratory
R. Muenchausen - Los Alamos National Laboratory
R. Del Sesto - Los Alamos National Laboratory
M. Bacrania - Los Alamos National Laboratory
L. Brown - Los Alamos National Laboratory
R. Reifarth - Gesellschaft f¨ur Schwerionenforschung
Abstract
Measurement of the neutron capture cross-sections of a number of short-lived isotopes is needed for continued analysis of data from nuclear weapons tests, for criticality and waste production estimates for the Advanced Fuel Cycle Initiative, and to advance understanding of nucleosynthesis. However, the high decay rate of the isotope sample and the high neutron flux required for this measurement result in a high background rate, necessitating a detector with a fast signal decay time. Current neutron capture experiments are unable to measure these cross-sections. Nanoparticles of an inorganic scintillator dispersed in a matrix material are a possible solution. Nanocomposite scintillators do not require the growth of large crystals, so they may permit the use of scintillating materials not currently available in the needed sizes and quantities. Cerium fluoride (CeF3) has been identified as a suitable scintillator for measuring neutron capture cross-sections of shortlived isotopes. We will present the manufacturing process and radiation characterization of CeF3 nanoparticle detectors. LA-UR-08-03801