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US 4,900,937 AGranted
Well logging detector with decoupling optical interface
AssigneeBicron Corporation
InventorsRoderick R. Dayton, Michael C. Papp, Glenn T. Tokos
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AssigneeBicron Corporation
InventorsRoderick R. Dayton, Michael C. Papp, Glenn T. Tokos
Estimating the term…
A well logging detector includes an elongated scintillation crystal having one end biased against and optically coupled to a transparent window portion of the detector housing. The biasing force on the crystal is provided by a compression spring located at and bearing against the other end of the crystal. The biasing force applied to the crystal by the spring is weak enough to allow the crystal to move away from and optically decouple from the window portion in response to shock forces on the detector. Subsequent to such shock induced decoupling, the biasing spring moves the crystal against the window portion to re-establish optical coupling therebetween. Such a biasing structure precludes excessive axial loading of the crystal by shock forces tending to move the crystal against the window as opposed to away from it. Such a shock resistant detector is especially well suited to measurement-while-drilling (MWD) applications.
In a well logging detector having a housing with a light transparent window portion, a scintillation member contained within the housing, the scintillation member generating light in response to ionizing radiation impinging on the scintillation member, and biasing means applying a biasing force against the scintillation member to hold it against and optically couple it to the window portion wherein the light generated by the scintillation member is transmitted to the exterior of the housing via the window portion, the improvement wherein said biasing force is weak enough to allow the scintillation member to move away from and optically decouple from the window portion in response to shock forces on the detector, the biasing means, subsequent to such shock induced decoupling, moving said scintillation member back against said window portion to re-establish optical coupling therebetween.
In a well logging detector having an elongated housing including at one end thereof a light transparent window portion, an elongated scintillation crystal coaxially contained within the housing, the scintillation crystal generating light in response to ionizing radiation impinging on the crystal, a compression spring contained within the housing and applying a biasing force against one end of the crystal, the other end of the crystal being biased against and optically coupled to said window portion wherein the light generated by the scintillation crystal is transmitted to the exterior of the housing via the window portion, the improvement wherein the biasing force is weak enough to allow the scintillation crystal to move away from and optically decouple from and separate from the window portion in response to shock forces on the detector, the biasing spring, subsequent to such shock induced decoupling, moving said scintillation crystal back against said window portion to reestablish optical coupling therebetween, wherein excessive axial loading of the elongated crystal by shock forces on the crystal tending to move the crystal against the window portion are minimized to preclude damage to the crystal and the window portion.
Dependencies are inferred from the claim text.