TESTING OF LIQUID SCINTILLATOR MATERIALS FOR GAMMA AND NEUTRON DETECTION1

Year
2009
Author(s)
A. Dougan - Lawrence Livermore National Laboratory
Les Nakae - Lawrence Livermore National Laboratory
Jerome Verbeke - Lawrence Livermore National Laboratory
Neal Snyderman - Lawrence Livermore National Laboratory
P.L. Kerr - Lawrence Livermore National Laboratory
Dan Dietrich - Lawrence Livermore National Laboratory
A. Glenn - Lawrence Livermore National Laboratory
R. Wurtz - Lawrence Livermore National Laboratory
Abstract
Liquid scintillators can be used to detect and measure the energy of both gamma-rays and fast neutrons. The advantage of liquid scintillators is that they are sensitive directly to fast neutrons (through neutron collisions and a recoiling protons that in turn excite the liquid scintillation material) and the scintillation preserves both an indirect measurement of the neutron’s momentum and the original timescale of its creation. These two characteristics are central to the new detection techniques we are developing for time-correlated neutron detection that are the basis for detecting, identifying and quantifying highly shielded SNM (particularly HEU). With currently available digitizing technology, one can detect both gamma-rays and fast neutrons with a time resolution of the order of nanoseconds and a high neutron/gamma discrimination. This paper describes the testing of liquid scintillators and results obtained in terms of discriminating power and detection efficiency in a close packed configuration with different sources.