Analysis of detector response using 3-D position-sensitive CZT gamma-ray spectrometers

Abstract

Two 2.25-cm 3 CdZnTe gamma-ray spectrometers with three-dimensional (3-D) position sensitivity were constructed and tested. By using 11 11 pixellated anodes and depth-sensing techniques, individual spectral data for each of 4800 voxels were collected throughout the detector volume. Energy resolution of 1.11% and 1.14% FWHM at 662 keV were obtained for single-pixel events from these two detectors, respectively. Spatial variations of electron mobility-lifetime product, energy resolution, photopeak efficiency, and total efficiency have been observed and analyzed. This analysis provides a direct observation on the uniformity of detector response (due to material, weighting potential, and electric field distribution) in 3-D. Possible defects in the detector are identified. The impact of the spatial variation of detector response on a CZT gamma-ray spectrometer is discussed.

Thickness scalability of large volume cadmium zinc telluride high resolution radiation detectors

“…Despite the advantages and great performance of CZT-based detectors that have been demonstrated extensively over the years, 1-19 these data have been done mainly on CZT detectors with thickness less than or equal to 6 mm or in "longer but small area" single-channel forms. Data on large volume with larger area and especially thicker sizes do exist [20][21][22][23] but this information has either been very limited or the applications have not yet been readily deployed in commercial mass production form. This is due to the lack of readily available CZT crystals that are inexpensive and having high resolution spectroscopy quality at the same time.…”

Technical note: Rapid and high‐resolution deep learning–based radiopharmaceutical imaging with 3D‐CZT Compton camera and sparse projection data

“…In recent years, the optimization of designs and reconstruction algorithms of CCs have been investigated by many groups 5–21 . Two main categories of CC are developed with different structures (i.e., single‐layer CC and multilayered CC) 7–9 .…”

“…However, the multilayered CCs usually are bulkier and more expensive, and most of their reconstruction quality is limited by the inherent energy resolution and spatial resolution due to the scintillation crystals without deep interaction information 13–15 . In contrast, three‐dimensional position‐sensitive CdZnTe (3D‐CZT) semiconductor CC with a compact structure, which has the advantages of a larger field of view, high energy resolution, and spatial resolution, has been developed in recent years 16,17 . Although the shorter Compton levers have a larger effect on the imaging deviation caused by the measurement errors of the spatial interaction positions and the energies deposited, the 3D‐CZT CC with portability and large field of view has unique advantages in nuclear medicine imaging.…”

“…4 In recent years,the optimization of designs and reconstruction algorithms of CCs have been investigated by many groups. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Two main categories of CC are developed with different structures (i.e., single-layer CC and multilayered CC). [7][8][9] Lots of clinical medical imaging experiments have been carried out with the multilayered CC.…”

“…[13][14][15] In contrast,three-dimensional positionsensitive CdZnTe (3D-CZT) semiconductor CC with a compact structure, which has the advantages of a larger field of view, high energy resolution, and spatial resolution, has been developed in recent years. 16,17 Although the shorter Compton levers have a larger effect on the imaging deviation caused by the measurement errors of the spatial interaction positions and the energies deposited, the 3D-CZT CC with portability and large field of view has unique advantages in nuclear medicine imaging.…”