X - RAY BACKSCATTER ( PAPER II ) Alan

In the presence of realistic soil inhomogeneities and surface clutter, employment of high-energy photon radiation (x rays or gamma rays) for landmine detection requires mine-feature imaging with centimeter spatial resolution. An x-ray backscatter method has been developed with photon detection efficiency sufficiently high such that an electric power requirement of only hundreds of watts yields a soil surface interrogation rate of 1 sq m per minute. Extensive laboratory measurements, and one test on the mine lanes at Fort A. P. Hill, Va., have demonstrated such results that it is estimated that mine detection probability is unity, false alarm probability is 0.03, and false alarm rate is 0.1 per square meter for mine depths of burial up to 5 cm. These results were achieved with a first developmental system, the components of which can be easily improved, and the imaging protocol of which can be modified to yield the same, or better, performance parameters up to mine depths of burial of 10 cm or more. This improved system will have weight less than 100 kg, will have about 1-m dimensions, and will be sufficiently rugged for real field applications. A manufactured unit cost will be on the order of $10,000.