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Proceedings Paper

Signal processing considerations in NMR detection of liquid explosives
Author(s): Lowell J. Burnett; Dale R. McKay
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Paper Abstract

High-resolution nuclear magnetic resonance (NMR) provides detailed spectral information on the molecular level. As such, it has been a principal tool of chemists since the early 1950s and used to probe the molecular structure, configuration and composition of liquids. However, high-resolution NMR techniques require very homogeneous DC and RF magnetic fields and are thus inappropriate as the basis for a practical liquid explosives screening system. These field requirements are relaxed for low-resolution NMR, but the unique spectral features of the high-resolution NMR signal are obscured. In spite of this, low-resolution NMR does provide substantial chemical information regarding liquids. Specific parameters available from low- resolution NMR include the signal amplitude (A0), the spin-lattice relaxation time (T1), the spin-spin relaxation time (T2), the diffusion constant (D), and the spin-spin coupling constant (J). Sequences of RF pulses can be designed to respond to one or more of these parameters and, therefore, unique NMR signatures for various liquids can be defined. General considerations of the relative importance of each of these parameters, along with practical considerations regarding allowable scanning and data processing times, will in large part determine the nature of signal processing methods to be used in the NMR Liquid Explosives Screening System.

Paper Details

Date Published: 1 April 1993
PDF: 11 pages
Proc. SPIE 1824, Applications of Signal and Image Processing in Explosives Detection Systems, (1 April 1993); doi: 10.1117/12.142899
Show Author Affiliations
Lowell J. Burnett, Quantum Magnetics, Inc. (United States)
Dale R. McKay, Quantum Magnetics, Inc. (United States)

Published in SPIE Proceedings Vol. 1824:
Applications of Signal and Image Processing in Explosives Detection Systems
James M. Connelly; Shiu M. Cheung, Editor(s)

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