Abstract: A scintillation detector apparatus comprising a filter disposed intermediate a scintillator and a detector, the filter being adapted to block relatively long wavelengths of light to reduce afterglow. The detector apparatus may, for example, be a part of a detector system such as a CT scanner, a RG system, or a geophysical measurement system.

Abstract: A radiation detector, in particular a gamma camera, is constructed and operated in such a fashion that only a predetermined number of light sensors (such as PMT's) adjoining each other in a cluster are used to generate a signal with amplitude and event position information. The camera may also use an array of individual scintillation elements (crystals) in place of a single crystal, with certain advantages obtained thereby. According to another aspect of the invention, there is a reflector sheet that defines an array of apertures through which scintillation light can pass from the scintillation crystal to a plurality of light sensors optically coupled to an optical window in an array corresponding to the array of apertures in the reflector.

Abstract: A gamma camera plate incorporates scintillation crystal which is sufficiently thick to effectively capture high energy radiation. The crystal is provided on its light output side with an array of light path-modifying partitions which extend partly through its thickness. These partitions define individual light collimating cells which reduce the light spreading which would otherwise prevent effective use of the plate for low energy radiation.

Abstract: A gamma camera plate incorporates scintillation crystal which is sufficiently thick to effectively capture high energy radiation. The crystal is provided on its light output side with an array of light path-modifying partitions which extend partly through its thickness. These partitions define individual light collimating cells which reduce the light spreading which would otherwise prevent effective use of the plate for low energy radiation.

Abstract: A gamma camera plate incorporates scintillation crystal which is sufficiently thick to effectively capture high energy radiation. The crystal is provided on its light output side with an array of light path-modifying partitions which extend partly through its thickness. These partitions define individual light collimating cells which reduce the light spreading which would otherwise prevent effective use of the plate for low energy radiation.

Abstract: A radiation detector, in particular a gamma camera, is constructed and operated in such a fashion that only a predetermined number of light sensors (such as PMT's) adjoining each other in a cluster are used to generate a signal with amplitude and event position information. The camera may also use an array of individual scintillation elements (crystals) in place of a single crystal, with certain advantages obtained thereby. According to another aspect of the invention, there is a reflector sheet that defines an array of apertures through which scintillation light can pass from the scintillation crystal to a plurality of light sensors optically coupled to an optical window in an array corresponding to the array of apertures in the reflector.

Abstract: A scintillation detector assembly is described which employs a scintillation phosphor such as a thallium activated sodium iodide crystal, wherein a blind hole is machined in the crystal to improve the efficiency of measuring the degradation rate of a radioactive material placed therein. The performance of the assembly is defined by the energy resolution of the radiation emanating from the radioactive source. This performance is improved by balancing the collection of light from areas of low and high light collection. This is achieved by suitably preparing the surfaces of the crystal and by controlling the reflectivity of these surfaces using controlled and fixed reflectivity material such as optical filters, cellulose ester-type fibrous paper and like materials. Improvements in resolution of 30 - 50% over prior art well assemblies have been measured for radioactive sources such as .sup.129 I.sub.53.