Abstract
We have recently completed a large-area, coded-aperture, gamma-ray imager for use in searching for radiation sources. The instrument was constructed to verify that weak point sources can be detected at considerable distances if one uses imaging to overcome fluctuations in the natural background. The instrument uses a rank-19, one-dimensional coded aperture to cast shadow patterns onto a 0.57 m 2 NaI(Tl) detector composed of 57 individual cubes each 10 cm on a side. These are arranged in a 19×3 array. The mask is composed of four-cm thick, one-meter high, 10-cm wide lead blocks. The instrument is mounted in the back of a small truck from which images are obtained as one drives through a region. Results of first measurements obtained with the system are presented.
Original language | English |
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Article number | 1645078 |
Pages (from-to) | 1614-1621 |
Number of pages | 8 |
Journal | IEEE Transactions on Nuclear Science |
Volume | 53 |
Issue number | 3 |
DOIs | |
State | Published - Jun 2006 |
Externally published | Yes |
Funding
Manuscript received January 27, 2005; revised November 3, 2005. This work was supported by the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory, under Contract W-7405-Eng-48. K. P. Ziock was with the Lawrence Livermore National Laboratory, Livermore, CA 94550 USA. He is now with Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA (e-mail: [email protected]). J. W. Collins, L. Fabris, and N. W. Madden are with the Lawrence Livermore National Laboratory, Livermore, CA 94550 USA. S. Gallagher, B. K. P. Horn, and R. C. Lanza are with the Massachusetts Institute of Technology, Cambridge, MA 02139 USA (e-mail: [email protected]; [email protected]). Digital Object Identifier 10.1109/TNS.2006.875285 Fig. 1. The coded-aperture imager. The mask and detector are fixed to an aluminum frame that maintains the imager focal length and alignment. The system is mounted to look through the curb side of the vehicle.
Keywords
- Coded aperture imager
- Gamma-ray detectors
- Gamma-ray imagers
- Nuclear imaging
- Orphan source search