Abstract: A method for growing a single crystal in a chamber. The method includes heating raw material to form a melt for forming the single crystal. A crystal seed is then inserted into the melt and pulled from the melt to form a partial ingot, wherein the partial ingot radiates heat. An amount of gas is then introduced into the chamber which corresponds to a size of the partial ingot so as to provide a constant crystallization rate.

Abstract: A method for growing a single crystal in a chamber. The method includes heating raw material to form a melt for forming the single crystal. A crystal seed is then inserted into the melt and pulled from the melt to form a partial ingot, wherein the partial ingot radiates heat. An amount of gas is then introduced into the chamber which corresponds to a size of the partial ingot so as to provide a constant crystallization rate.

Abstract: A single crystal pull apparatus has a multilayer crucible wherein the crucible has an outer crucible, an insertable layer intimately fitted thereon, and a wire frame positioned between the insertable layer and an inner crucible. The insertable layer, wire frame and inner crucible are preferably composed of platinum. Furthermore the insertable layers have thin walls and the frame has a small diameter such that they can be easily reshaped after any deformation occurring as a result of the single crystal growth process.

Abstract: An apparatus and method is provided for pulling a crystal seed from melt for growing a single crystal. The method includes the steps of providing a crucible and providing within the crucible an outer container, and providing coaxially within the outer container an inner container. A protruding portion of the inner container protrudes downward relative to the outer container for containing melt, the inner and outer containers defining an annular channel therebetween which has a bottom wall and contains introduced charge feed. The method further includes the steps of providing for allowing fluid communication between the annular channel and the inner container, delivering charge feed into the annular channel, and generating heat from within the annular channel for preventing the formation of a condensate of the charge feed within the annular channel.

Abstract: A single crystal pull apparatus has a multilayer crucible wherein the crucible has an outer crucible, an insertable layer intimately fitted thereon, and a wire frame positioned between the insertable layer and an inner crucible. The insertable layer, wire frame and inner crucible are preferably composed of platinum. Furthermore the insertable layers have thin walls and the frame has a small diameter such that they can be easily reshaped after any deformation occurring as a result of the single crystal growth process.

Abstract: A system and method for cutting soluble scintillator material are disclosed. The system includes a scintillator cutting apparatus including a filament rotated around a plurality of pulleys in at least one direction and in operative proximity to the material thereby cutting the material. The system also includes a linear motion motor operatively connected to the scintillator cutting apparatus for moving the apparatus to position the filament in operative proximity and a linear motion speed sensor for sensing rate of movement of the apparatus as the apparatus is moved by the linear motion motor to position the filament in operative proximity. The system further includes a master motor controller operatively connected to the linear motion motor and the linear motion sensor, wherein the master motor controller controls the linear motion motor as a function of sensed information obtained from the linear motion speed sensor.

Abstract: An apparatus and method is provided for pulling a crystal seed from melt for growing a single crystal. The method includes the steps of providing a crucible and providing within the crucible an outer container, and providing coaxially within the outer container an inner container. A protruding portion of the inner container protrudes downward relative to the outer container for containing melt, the inner and outer containers defining an annular channel therebetween which has a bottom wall and contains introduced charge feed. The method further includes the steps of providing for allowing fluid communication between the annular channel and the inner container, delivering charge feed into the annular channel, and generating heat from within the annular channel for preventing the formation of a condensate of the charge feed within the annular channel.

Abstract: A system and method for cutting soluble scintillator material are disclosed. The system includes a scintillator cutting apparatus including a filament rotated around a plurality of pulleys in at least one direction and in operative proximity to the material thereby cutting the material. The system also includes a linear motion motor operatively connected to the scintillator cutting apparatus for moving the apparatus to position the filament in operative proximity and a linear motion speed sensor for sensing rate of movement of the apparatus as the apparatus is moved by the linear motion motor to position the filament in operative proximity. The system further includes a master motor controller operatively connected to the linear motion motor and the linear motion sensor, wherein the master motor controller controls the linear motion motor as a function of sensed information obtained from the linear motion speed sensor.

Abstract: A process control system for a crystal-growing apparatus is provided which includes a process controller and a temperature controller. The temperature controller includes an input terminal which receives a temperature adjustment signal from a bottom heat thermocouple indicating the melt temperature. Based on the melt temperature, the temperature controller determines whether to increase, decrease or keep constant the melt temperature. The temperature controller further includes two additional input terminals which receive pulses from a pulse generator of the process controller for automatically controlling temperature switches of a bottom heater temperature controller in accordance with the sensed level of the melt. The pulses are generated by the pulse generator upon receiving data with respect to how much the temperature needs to be adjusted and in which direction (increase or decrease).

Abstract: A gamma camera is provided having an array of photodetectors and associated circuitry for detecting and converting light energy to electrical energy. The gamma camera further includes a scintillation crystal positioned in proximity to the array of photodetectors for detecting gamma photon emissions and generating light energy. At least one portion of at least one surface of the scintillation crystal is polished differently than at least another portion for yielding a substantially different light response function for the generated light energy. That is, the scintillation crystal is non-uniformly polished or has a non-uniform level of smoothness. The non-uniformly polished scintillation crystal improves signal-to-noise ratio and image quality with respect to spatial resolution.

Abstract: A method and device for stabilizing photomultiplier tubes of a radiation image device against drift by illuminating the photomultiplier tubes with light. A certain number of the photomultiplier tubes are arranged in an array for final application. Then the complete array is illuminated for a certain time period with light having an intensity to produce an average anode current in the photomultiplier tubes which is in the range of 1 to 50 .mu.A.