THE DTRA PROGRAM FOR LONG-RANGE DETECTION OF NUCLEAR THREATS

The Defense Threat Reduction Agency is a combat support agency of the U.S. Department of Defense. Its mission is to protect the USA and its allies from Weapons of Mass Destruction by providing capabilities to reduce, eliminate, and counter the threat and mitigate its effects. Military defense organizations have responsibility to respond to threats involving “loose nukes” anywhere world wide. Since military forces need to be able to locate threat objects or materials at long distance, on short notice and in hostile environments not fully under their control, standoff detection systems need to be transportable on military platforms. Technologies are needed for detection of nuclear threats under circumstances where they could not be detected on the basis of their intrinsic radiations, for example, because of distance or shielding. One approach that could enable detection of shielded materials or threat objects at long range is to use interrogating radiation to stimulate emissions that can locate and identify SNM at greater distance than is possible with passive techniques. Approaches being explored include use of photons, protons, negative muons and neutrons as the interrogating radiation to stimulate response from SNM. In addition to accelerator-based technologies, laser techniques can provide long-range identification of trans-actinide elements, for example in surface contamination, and of chemicals unique to nuclear-related activities. Non-conventional signatures, such as radiation- induced atmospheric fluorescence, also offer potential for detection of nuclear threats at long- standoff distances. Other elements of the DTRA program include development of compact, high- gradient accelerator technology and modeling and simulation of scenarios where experimental evaluation is impractical.