Abstract: Characterization, calibration and gain stabilization of gamma ray detectors are carried out using one or more spectral features that are present in the background radiation. Such a spectral feature may be the spectral peak associated with Potassium-40 nuclide. The disclosed methods, apparatus and computer program products enable uninterrupted operation of gamma ray detection systems, while eliminating the costs associated with the procurement and integration of external reference sources into these systems, and without compromising the sensitivity of the detection system.

Abstract: A radiation detection unit includes a housing and isolators unitarily constructed from mechanical energy absorbent material. The housing is attached rigidly to a structure and its major dimensions are selected to exceed corresponding major dimensions of a radiation sensor. The isolators have a body portion and projections extending outwardly therefrom. The body portion engages the radiation detection sensor proximal a respective one of its radiation collection end and its interface end. The projections are disposed intermediate the body portion and an interior surface of the housing and have a distal end contacting the interior surface to carry the radiation sensor in a three dimensional spaced apart relationship to the interior surface. The length of the projections is selected to attenuate substantially mechanical energy that is induced at the distal end and propagates along the length of each projection prior to the propagated energy being incident upon the body portion.

Abstract: A computer program, database and method for the detection of fissile or radioactive material or radiation shielding material in a container works with detection devices brought into proximity to containers so that the presence of fissile or radioactive material, or shielding materials to conceal the presence of such fissile or radioactive materials, may be detected. A comparison may then be made of the output of the detector to a threshold to determine subsequent action regarding the shipping container. The threshold may be based on the output of known, dangerous radioactive materials, known legitimate contents or empty containers.