System and method for contraband detection using nuclear quadrupole resonance including a sheet coil and RF shielding via waveguide below cutoff
US5592083A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 1995 |
| Grant date | Jan 7, 1997 |
| Priority date | — |
| Expiry date | Mar 8, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N24/084
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for detecting a target substance within a class of explosives and narcotics containing quadrupolar nuclei through the use of nuclear quadrupole resonance (NQR). The system applies an RF signal to a coil to excite the substance under test. If the target material is present, an NQR signal will be picked up by the same coil. That signal is compared with known NQR signals in frequency and amplitude. A signal is displayed in an appropriate way if a threshold value of the NQR signal is equalled or exceeded. The coil is tuned by means of an auto-tune feature. Effective RFI shielding is provided to prevent external contaminating signals from being detected by the coil and to prevent RF signals from escaping from the scanner. The invention also includes the method for performing tests with the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.