Arrays of Position-Sensitive Virtual Frisch-Grid CdZnTe Detectors: Results From a $$4\times 4$$ Array Prototype

Journal Article · Tue Aug 22 00:00:00 EDT 2017 · IEEE Transactions on Nuclear Science

DOI:https://doi.org/10.1109/TNS.2017.2743160· OSTI ID:1426652

Ocampo Giraldo, L. A.  ^[1]; Bolotnikov, A. E. ^[2]; Camarda, G. S. ^[2]; Cheng, S. ^[2]; De Geronimo, G. ^[2]; McGilloway, A. ^[2]; Fried, J. ^[2]; Hodges, D. ^[3]; Hossain, A. ^[2]; Unlu, K. ^[1]; Petryk, M. ^[2]; Vidal, V. ^[3]; Vernon, E. ^[2]; Yang, G. ^[2]; James, R. B. ^[2]

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1. Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering
2. Brookhaven National Lab. (BNL), Upton, NY (United States)
3. Univ. of Texas, El Paso, TX (United States)

Position-sensitive virtual Frisch-grid (VFG) CdZnTe (CZT) detectors offer a unique capability for correcting the response nonuniformities caused by crystal defects. This allowed us to achieve high energy resolution, while using typical-grade commercial CZT crystals with relaxed requirements to their quality, thus reducing the overall cost of detectors. Another advantage of the VFG detectors is that they can be integrated into arrays and used in small compact hand-held instruments or large-area gamma cameras that will enhance detection capability for many practical applications, including nonproliferation, medical imaging, and gamma-ray astronomy. Here in this paper, we present the results from testing small array prototypes coupled with front-end application-specified integrated circuit. Each detector in the array is furnished with 5-mm-wide charge-sensing pads placed near the anode. The pads signals are converted into XY coordinates, which combined with the cathode signals (for Z coordinates) provide 3-D position information of all interaction points. The basic array consists of a number of detectors grouped into 2×2 subarrays, each having a common cathode made by connecting together the cathodes of the individual detectors. Lastly, these features can significantly improve the performance of detectors while using typical-grade low-cost CZT crystals to reduce the overall cost of the proposed instrument.

• Research Organization: Savannah River Site (SRS), Aiken, SC (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
• Grant/Contract Number: AC09-08SR22470; AC02-98CH1886
• OSTI ID: 1426652
• Report Number(s): SRNL-STI-2017-00080; TRN: US1802840
• Journal Information: IEEE Transactions on Nuclear Science, Vol. 64, Issue 10; ISSN 0018-9499
• Publisher: IEEE
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
3-D position-sensitive virtual Frisch-grid (VFG) detectors
cdZnTe (CZT)
charge-loss correction
crystal defects
high-granularity detectors
Detectors
Anodes
Cathodes
Crystals
Energy resolution
Timing
Testing