METAL SHIELD ALARM IN A NUCLEAR QUADRUPOLE RESONANCE/X-RAY CONTRABAND DETECTION SYSTEM

摘要

This invention relates to a combined nuclear quadrupole resonance and X-ray contraband detection system with a metal shield alarm that is activated when the area of the metal in the object being scanned as determined by the resonance frequency shifts of the NQR sensors exceeds the area of the metal in the object being scanned as determined by X-rays by an amount sufficient to shield contraband.