ABSTRACT
Thus far, detection of guns and bombs has largely been by detection of metal, though dogs and chemical sniffers are also now increasingly used for detecting explosives. A great deal of further development, however, is needed in the detection of plastic and other materials and of explosives by various kinds of penetrating ray or radiation, the most promising being by neutron bombardment and the detection of dielectric properties of materials. Trends and prospects will be examined in this chapter.
