Abstract: The light collection efficiency of plastic scintillators used to detect low energy ?-ray radiation is improved by utilizing diffuse reflective materials instead of specular reflective materials.

Abstract: A compact medical nuclear imaging device, which generates a medical image from gamma radiation, can be held stationary or moved to search a large area for locating a radioactive area of interest. The compact medical imaging device comprises a collimator having an array of collimating channels, a radiation collection module converting the gamma radiation to an electric signal, an electronic module for processing the electrical signal, and a display module for displaying a two-dimensional image of the radiation scene, all of which preferably are assembled together in a single, compact module of a size small enough to permit it to be held and maneuvered by a human operator.

Abstract: A scintillation crystal module having an epoxy seal which has a coefficient of thermal expansion which is substantially the same as the backcap of the gamma camera. Among the suitable epoxy systems, the CTE of the epoxy could be modified somewhat by choosing a different catalyst or by adjusting the resin:catalyst ratio. The presently preferred epoxy system is a STYCAST.RTM. 2850 FT system available from W. R. Grace & Co. Using "catalyst 9" or "catalyst 11" from that system, a CTE of approximately 17.33.times.10.sup.-6 to approximately 19.4.times.10.sup.-6 in/in.degree. F. can be easily achieved. It has been discovered through analysis using FEA that an epoxy with a CTE in the range of 9.0 to 20.0.times.10.sup.-6 in/in.degree. F. provides satisfactory results in preventing seal separation during .+-.40.degree. F. temperature cycles.