Year
1997
Abstract
In the nuclear safeguards and arms control areas, well-developed methodologies exist for determining the properties of nuclear materials via measurements of the gamma rays and neutrons emitted from these materials, or in the arms control area, by the use of radiography. In certain favorable instances, it may by feasible to perform comparable measurements with the use of a ubiquitous, naturally-occurring radiation - cosmic ray mu mesons (muons). At the earth's surface these charged particles have a broad energy distribution peaking at about 500 MeV with a flux of approximately 10-2/cm2- sec-steradian. In traversing matter, muons lose energy at a rate of approximately 2 MeV/gram almost independent of atomic number. Muons can readily be detected by either plastic scintillators or wire planes. While the flux is small, a scintillator of one meter area, for example, will register about 20,000 events/min. These particles should have utility in the detection and imaging of objects with sectional densities of a few hundred grams/cm2. The degree of intrusiveness of the imaging can be controlled through the detector configuration. Some possible applications include: 1. Mass measurements on large UF6 cylinders, 2. Determination of the size of treatylimited objects, e.g., missiles, in rail cars or other containment, 3. Verification of single or multiple warheads or components, 4. The detection of concealed, underground cavities. Examples will be presented.