title: Preliminary evaluation of a novel energy-resolved photon-counting gamma ray detector.
abstract: In this paper, we present the design and preliminary performance evaluation of a novel energy-resolved photon-counting (ERPC) detector for gamma ray imaging applications. The prototype ERPC detector has an active area of 4.4 cm × 4.4 cm, which is pixelated into 128 × 128 square pixels with a pitch size of 350 µm × 350µm. The current detector consists of multiple detector hybrids, each with a CdTe crystal of 1.1 cm × 2.2 cm × 1 mm, bump-bonded onto a custom-designed application-specific integrated circuit (ASIC). The ERPC ASIC has 2048 readout channels arranged in a 32 × 64 array. Each channel is equipped with pre- and shaping-amplifiers, a discriminator, peak/hold circuitry and an analog-to-digital converter (ADC) for digitizing the signal amplitude. In order to compensate for the pixel-to-pixel variation, two 8-bit digital-to-analog converters (DACs) are implemented into each channel for tuning the gain and offset. The ERPC detector is designed to offer a high spatial resolution, a wide dynamic range of 12-200 keV and a good energy resolution of 3-4 keV. The hybrid detector configuration provides a flexible detection area that can be easily tailored for different imaging applications. The intrinsic performance of a prototype ERPC detector was evaluated with various gamma ray sources, and the results are presented.
authors.affiliation: Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, 214 Talbot Lab, Urbana, IL 61801, USA.
authors.forename: L-J
authors.initials: LJ
authors.lastname: Meng
authors.affiliation: Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, 214 Talbot Lab, Urbana, IL 61801, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Tan
authors.affiliation: Oy Ajat Ltd., Tietotie 3, FIN-02150 Espoo, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Spartiotis
authors.affiliation: Oy Ajat Ltd., Tietotie 3, FIN-02150 Espoo, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Schulman
keywords: CdTe; Energy-resolved photon counting; Gamma ray imaging