Principles Of The Creation Of Scintillation Detectors For Severe Operation Conditions

INTRODUCTION At the first sight a detector is not a complicated optical system: a scintillator optically coupled with glass, enveloped in a light reflecting coating and as a rule hermetically packed in a housing. But in practice several different optical and constructional materials are combined in a detector. Depending on operational requirements when selecting the materials there arise technical contradictions due to the difference in the physical properties. Elimination of these contradictions leads to the appearance of new solutions in other fields of science and engineering, obtaining new materials. The application of the scintillation detectors in geophysical research (radioactive logging of deep wells, aerial survey etc.) defines the demands to their ability to operate in a wide temperature range, high sensitivity and efficiency of the registration of the ionizing radiation, resistance to mechanical loadings 111. The increase of sensitivity and efficiency of y-radiation registration is complicated by the limitations in diameter of the detector and can be achieved only by increasing the height of the scintillator or using the scintillation materials with a higher atomic number. Utilization of conventional scintillators (A B , complex oxides etc.) for this purpose is at present problematic due to the difficulties in obtaining crystals of necessary size, high light output, good transparency to the intrinsic radiation, high thermal resistance. I1 VI