Abstract: A radiation detector useful for well logging and other applications contains a stabilizing pulsar device comprising a scintillator coupled to a photodetector and including a radio-active source such as an Am.sup.241 which simultaneously emits gamma rays and low energy particles such as .alpha. or .beta. particles upon decay. The pulsar device is coupled to the radiation detector which utilizes a scintillation crystal and photodetector, and the outputs from the two photodetectors are processed through a coincident/anti-coincident gate alternately to stabilize the gamma rays or to read the environmentally induced radiation.

Abstract: A rugged scintillation detector uses a hermetically sealed window assembly welded or otherwise bonded to the detector housing. A method and apparatus useful in forming a reproducible hermetic seal between the glass and an annular metal retaining ring is described. The glass and ring are chosen so that the ring diameter is slightly larger than that of the glass at room temperature. A thin layer of frit at the interface ensures a very tight mechanical seal, and a surface layer of chromium oxide on the ring ensures a secure chemical bond. The assembly device uses pressure and counterpressure to uniformly and reproducibly assemble the glass window into the retainer ring at elevated temperatures.

Abstract: Scintillators, and more particularly inorganic scintillation crystals such as cadmium tungstate, bismuth germanate, barium fluoride and calcium fluoride are coated with successive coatings of particulate materials such as barium sulfate and titanium dioxide to provide a highly reflective surface layer capable of providing internal reflection of scintillation events in the region of 200-700 nm. The reflective surface enhances the pulse height and resolution of the scintillator when coupled to a suitable detector such as a photomultiplier tube or a silicon photodiode.

Abstract: A light-reflective, flowable and curable composition is described which comprises a resin containing light-reflective solid particles in an amount and of average particle size sufficient to provide the desired light reflectance/transmittance characteristics to the cured composition. Preferably, the composition is self-leveling, and the solid particles may be particles of magnesium oxide, barium sulfate, aluminum oxide or mixtures thereof. The compositions of the invention are useful as reflective coatings in various applications such as for radiation detector devices including scintillator crystals.