Neutron Capture Gamma Rays ( Thermal Neutron

Detection of landmines using nuclear techniques has been studied extensively since the late 1940s. Nuclear techniques look at either a return radiation, which is characteristic of explosive components that are infrequently found in soil (e.g., nitrogen or carbon), or an intensity change of a noncharacteristic scattered radiation, which is a function of a parameter that differs between soil and explosives. Noncharacteristic radiation methods are essentially anomaly detectors; that is, they detect inhomogeneities in the medium and inclusions in addition to mines. Virtually every conceivable nuclear reaction has been examined, but after considering a number of factors (many of them linked)—including selectivity, sensitivity, probability of detection, false alarm rate, soil absorption, time to make a detection, limitations due to fundamental physics, and technical limitations (size, weight, power, present and future availability of sources and detectors)—only a few have potential for mine detection. Probably the most thorough examination of nuclear reactions for landmine detection is the report by Coleman et al. [1] sponsored by the U.S. Army Mobility Equipment Research and Development Center (now called the Night Vision and Electronic Sensors Directorate). A workshop was held in 1985 to revisit the conclusions of the Coleman report in light of advances in technology and to identify any nuclear