Year
2011
Abstract
Recent efforts have been focused on the development of new, efficient scintillation detectors for fast neutron detection and spectroscopy. These detectors have application in several areas, including nuclear nonproliferation and homeland security. The selection of a particular detector relies on accurate evaluations of its neutron detection efficiency and spectroscopic capabilities. To this end, a measurement campaign was performed at the Joint Research Centre (JRC) in Ispra, Italy in June 2010 jointly by University of Michigan, Los Alamos National Laboratory, and JRC personnel. In this work, we present new neutron pulse-height distributions from well-characterized mixed-oxide fuel, plutonium metal, and isotopic neutron sources measured with five different organic scintillation detectors: (i) traditional liquid (EJ-309), (ii) C6D6 liquid, (iii) Cd- plastic, (iv) B-10 loaded liquid, and (v) Li-6 glass/plastic slabs. Detector performance is compared for experiments performed with a digital data-acquisition system using the same experimental conditions for all detectors, and a comparison to a traditional He-3-based system is presented. Specifically, we analyze neutron detection efficiency by measurement of neutron pulse-height distributions for a variety of well-known neutron sources, including Cf- 252, AmBe, AmF, plutonium metal, and mixed-oxide fuel. Finally, the measurement scenarios are modeled using the MCNPX-PoliMi code and good agreement is observed between the measured and simulated pulse-height distributions. The paper describes the detailed procedures for performing these measurements and the resulting measured data for all the neutron sources. An outlook on the use of these detectors for source characterization and neutron spectroscopy will be provided.