New Virtual Frisch-Grid CdZnTe Detector Design With Sub-Millimeter Spatial Resolution

We evaluated the performance of a position-sensitive virtual Frisch-grid (VFG) CdZnTe detector, 6 mm ×6 mm ×15 mm, via sensing strips on its side surfaces. Once the signals were collected from the anode, and from four or eight strips attached to the detector´s sides, we assessed the anode´s energy spectra and derived histograms from the side electrodes to evaluate the feasibility of achieving sub-millimeter spatial resolution in the X-Y plane. Using a highly collimated 30-keV X-ray beam at the National Synchrotron Light Source, and applying corrections to the raw data, we determined the photon-interaction points by conventional Anger logic and via a more sophisticated statistics-based positioning (SBP) algorithm. With the VFG detector´s current configuration, we achieved a resolution below 1 mm, even for low-energy X-rays.