Abstract: An apparatus for growing crystals includes a sealed chamber having a crucible assembly and a seed holder disposed therein. The crucible assembly is adapted to contain a melt therein and the seed holder is selectively positionable within the chamber from a first position relative to the crucible assembly to at least one subsequent position within the crucible assembly. A heater is configured and dimensioned to heat the melt disposed within the crucible assembly and an insulator is included for insulating the heater and the crucible. An actuator rotates at least one of the crucible assembly and the seed holder relative to the other and a support ring suspends the crucible assembly within the sealed chamber. A ceramic thermal shield is disposed atop the support ring and regulates the heat loss from the crucible assembly to an upper portion of the chamber.

Abstract: An apparatus for growing crystals includes a sealed chamber having a crucible assembly and a seed holder disposed therein. The crucible assembly is adapted to contain a melt therein and the seed holder is selectively positionable within the chamber from a first position relative to the crucible assembly to at least one subsequent position within the crucible assembly. A heater is configured and dimensioned to heat the melt disposed within the crucible assembly and an insulator is included for insulating the heater and the crucible. An actuator rotates at least one of the crucible assembly and the seed holder relative to the other and a support ring suspends the crucible assembly within the sealed chamber. A ceramic thermal shield is disposed atop the support ring and regulates the heat loss from the crucible assembly to an upper portion of the chamber.

Abstract: An improved method of, and apparatus for, nuclear imaging takes advantage of the ability to determine the depth of gamma ray/electron interaction within a semiconducting gamma ray detector to determine the (most highly probable) location of the first gamma ray/electron interaction within the detector. Lines of interaction constructed between opposing detector arrays, extending between the location of the first gamma ray/electron interaction in each detector associated with the coincident detection of gamma radiation, permits a positron-emitting object of interest to be imaged according to protocols known in the art, but with better spatial resolution than previously believed to have been known.