Year
2009
Abstract
Capture-gated detectors are suitable for neutron spectroscopy in mixed neutron and gamma-ray fields. This is because they are less prone to neutron misclassification due to additional measured information available. This information is an additional capture pulse that typically follows the initial neutron scattering pulse. This ‘dual’ signal results in more accurate neutron detection, which is beneficial in many applications. The mixed fields are ‘typical’ for nuclear safeguards, nuclear nonproliferation, and national security, thus capture-gated detectors might represent a new generation of detectors in these applications. One of commercially available capture-gated detectors is a BC-523A detector. This detector is a 10B-loaded liquid scintillation detector that is sensitive to not only fast neutrons and gamma rays, but also to thermal neutrons. Thus, three different signals are measured that can be distinguished from each other. This detector has recently attracted the attention of researchers because it has shown promise for full-energy neutron spectroscopy. Several efforts have been made to accurately characterize this detector for several neutron and gamma-ray energies. In this paper, we present measurement and simulation results for different monoenergetic neutron beams that were used to obtain the energy-dependent response of the detector. This work is a part of a large project that is focused on accurate characterization of capture-gated detectors to determine their potential for neutron spectroscopy applications, especially for nuclear nonproliferation and homeland security. Keywords: liquid scintillator; capture-gated detector; pulse shape discrimination; neutron spectroscopy; special nuclear material; fast digitizer