|Acquisition Program: || Objective: ||To develop a radiation detection system capable of detecting and discriminating between fast neutrons (> 1 eV) and gamma rays for use in the active and passive detection of special nuclear materials SNM).
|| Description: ||The Defense Threat Reduction Agency (DTRA) seeks innovative methods for detecting and discriminating between neutrons with energies > 1 eV and gamma radiation. The conventional method for detecting neutron radiation involves moderating neutrons to thermal energies so they can be absorbed by detector materials that is are most sensitive to thermal neutrons. However, during this moderating process, much of the lifetime information of the individual neutrons is lost; including energy and directional information. Such information can be critical in identifying the source of neutron radiation. The detector developed through this research must be able to discriminate between neutron and gamma interactions in the detector. Additionally, the detector must be able to operate within 1-micro second following a 3-micro second pulse of 1010 photons, which may be regularly repeated at up to 1-KHz.
|| ||PHASE I: Develop design(s) for fast neutron (> 1 eV) and/or gamma-ray detection systems that offer both the potential of achieving the above requirement significant improvement over present detector technology. Demonstrate experimentally that a detector design is feasible and that achieving the refresh cycle in the objective is theoretically feasible.
|| ||PHASE II: Develop a prototype device and demonstrate it in a laboratory environment. A comparison to the above objective would result.
|| ||PHASE III DUAL USE APPLICATIONS: Fast neutron and gamma ray detectors can be used in a variety of applications to include the passive and active detection of SNM. For active applications, the detectors will be integrated with either neutron or high-energy gamma ray sources in order to either detect penetrating radiation or radiation resulting from fission. Fast neutron and gamma detectors would have relevance in the medical and other commercial industries for use in tomography and radiography applications.
|| References: ||1. Smith, M.B., H.R. Andrews, E.T.H. Clifford, H. Ing, V.T. Koslowsky, R.T. Noulty, M. Zhang, L.G.I. Bennett, M.L. Boudreau, A.R. Green, B.J. Lewis, R. Nolte, and S. Röttger. Canadian High-Energy Neutron Spectrometry System (CHENSS). International Workshop on Fast Neutron Detectors and Applications, 3 Apr. 2006. 8 Aug. 2006 <http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=25#session-1>.
2. Glasstone, Samuel, and Philip J. Dolan. United States of America. Department of Defense. The Effects of Nuclear Weapons. Washington, DC: US Government Printing Office, 1977.
3. Knoll, Glenn F. Radiation Detection and Measurement. 3rd ed. New York: John Wiley & Sons, Inc., 2000.
4. Bücherl, Thomas, and Christoph Lierse von Gostomski. Radiography Using Fission Neutrons. International Workshop on Fast Neutron Detectors and Applications, 3 Apr. 2006. 8 Aug. 2006 <http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=25#session-1>.
|Keywords: ||Radiation Detection, Semiconductors, High Voltage Bias, Charge Collection, Gamma Ray Spectrometry|