Cadmium Zine Telluride (CZT) has been extensively studied as a room temperature semiconductor gamma
radiation detector. CZT continues to show promise as a bulk and pixelated gamma spectrometer with less than one
percent energy resolution; however the fabrication costs are high. Improved yields of high quality, large CZT
spectroscopy grade crystals must be achieved. CZT is grown by the Traveling Heater Method (THM) with a Te
overpressure to account for vaporization losses. This procedure creates Te rich zones. During growth, boules will often
cleave limiting the number of harvestable crystals. As a result, crystal growth parameter optimization was evaluated by
modeling the heat flow within the system. Interestingly, Cadmium Telluride (CdTe) is used as a thermal conductivity
surrogate in the absence of a thorough study of the CZT thermal properties. The current study has measured the thermal
conductivity of CZT pressed powders with varying Te concentrations from 50-100% over 25-800°C to understand the
variation in this parameter from CdTe. Cd0.9Zn0.1Te1.0 is the base CZT (designated 50%). CZT exhibits a thermal
conductivity of nearly 1 W/mK, an order of magnitude greater than CdTe. Further, the thermal conductivity decreased
with increasing Te concentration.
Miniaturized Micro-Pocket Fission Detectors (MPFD) are under investigation as real-time neutron flux monitors. The devices are capable of performing near-core and in-core reactor power measurements. The basic design utilizes neutron reactive material confined within a miniaturized gas pocket, similar to that of a fission chamber. Device size ranges from 500 microns to a few millimeters thick, thereby allowing them to be inserted directly between fuel elements of a reactor core. Fabricated from inexpensive ceramic materials, the detectors can be fashioned into a linear array to facilitate 3-D mapping of a reactor core neutron flux profile in "real-time". Initial tests have shown these devices to be extremely radiation hard and potentially capable of operating in a neutron fluence exceeding 1016 n cm-2 without noticeable degradation.