Various vital disciplines (e.g., dosimetry, radiation field surveys, non-proliferation accounting and treaty verification) currently need a compact, reasonably efficient radiation spectrometer that can operate at room temperature. CdZnTe is recognized as a material that can provide high resolution gamma spectroscopy at room temperature, but with a poor manufacturing yield. We propose a design (Trapezoidal-shaped Frisch grid) of the CdZnTe detector that can utilize a poorer grade of CdZnTe crystal, and therefore, might significantly improve the fraction of the CdZnTe boule that can be used for spectroscopy applications. Radiation detectors will be made using a trapezoidal-shaped Frisch grid design. This design should permit a lower grade of CdZnTe crystal to be used for spectroscopy. The lower grade crystals will be assembled and electronically linked in an array, forming a probe with a large volume. By being able to use a lower grade crystal, more of the boule can be utilized for spectroscopy. In Phase I, Trapezoid Frisch grid CdZnTe devices will be manufactured from various grades of raw CdZnTe material. After the devices are packaged and tested, the resolution and sensitivity of each grade of crystal will be determined. The results will be used to determine what grade of CdZnTe crystal is usable for spectroscopy and therefore, the fraction of the boule that can be used for spectroscopy applications.
Commercial Applications and Other Benefits as described by the awardee: The devices constitute a novel design for high resolution room temperature operated semiconductor-based gamma-ray spectrometer detectors. Successful implementation will bring about more widespread use of CdZnTe and similar compound semiconductors for radiation detection.
