PHYSICS AND MATHEMATICS PAPER ABSTRACTS.
RECENT PROGRESS IN HOLOGRAPHIC IMAGING OF OPALS. D. BRIAN THOMPSON, UNIVERSITY OF NORTH ALABAMA.
A Denisyuk reflection hologram is created by placing a holographic plate in front of an object so that the object is illuminated through the plate by a diverging, monochromatic laser beam. In this setup, a holographic image of the object is created by light wave interference between the incident beam and laser light reflecting off the object. Then the monochromatic holographic image can be reconstructed by illuminating the reflection hologram with a white light source. We have begun using several different colors of incident laser beams to produce full-color reflection holograms. We select gem opals as the objects to be imaged. The flashes of color in gem opals result from light wave interference, and so full-color reflection holograms are especially suited to reproducing these flashes of color. Here I demonstrate progress we've made in producing these holograms and set future goals for this project.
IN SITU CURRENT-VOLTAGE CHARACTERISTICS OF CDZNTE IN EXTREME THERMAL ENVIRONMENTS. TYLER RICHARDSON, MATTHEW DOWDELL, ROBERT E. SMITH II, EMMANUEL JODA, OLASUNKANMI ROWLAND, JONATHAN S. LASSITER AND STEPHEN O. BABALOLA, ALABAMA A&M UNIVERSITY.
There is a need for robust detection systems capable of operating in extreme thermal conditions, and Cadmium Zinc Telluride (CZT) shows promise for detection in extreme environments. CZT has been proven to be an effective room temperature radiation detection material with applications in medical imaging, nuclear non-proliferation, reactor monitoring, as well as gamma- and X-ray astronomy. This work was guided by research characterizing the electrical properties of CZT crystals following thermal treatments, however, in situ electrical properties characterization is needed to mimic real-life applications during exposure to environments with elevated temperatures. These experiments served to evaluate the electrical properties of CZT detectors during operation at elevated temperatures. I-V measurements were obtained while the detector, placed inside of a furnace, in the range of 20oC - 400oC. The results of this series of experiments is important in the application of radiation detection in extreme temperature environments, and the design of robust detection systems capable of effective operation during exposure to extreme conditions. In this study the I-V profiles of nuclear radiation detectors fabricated based on Cadmium Zinc Telluride (CdZnTe or CZT) semiconductor crystals are obtained and analyzed. The I-V notes a logarithmic decrease in resistivity to 200oC, and the deterioration of electrical properties is less drastic beginning with measurements at and following 250oC. The results of this study indicate that a CZT detector system can operate up to lOOoC with minimal modifications to a detector configuration, beyond that point, further modifications will likely be required.