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Title: Study of sub-pixel position resolution with time-correlated transient signals in 3D pixelated CdZnTe detectors with varying pixel sizes

Journal Article · · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
 [1];  [2];  [2];  [2];  [2];  [2];  [3];  [2];  [4];  [2];  [2];  [5]
  1. Pennsylvania State Univ., University Park, PA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
  3. University of Texas, El Paso, TX (United States)
  4. Pennsylvania State Univ., University Park, PA (United States)
  5. Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

In this work, we evaluated the sub-pixel position resolution achievable in large-volume CdZnTe pixelated detectors with conventional pixel patterns and for several different pixel sizes: 2.8 mm, 1.72 mm, 1.4 mm and 0.8 mm. Achieving position resolution below the physical dimensions of pixels (sub-pixel resolution) is a practical path for making high-granularity position-sensitive detectors, <100 μm, using a limited number of pixels dictated by the mechanical constraints and multi-channel readout electronics. High position sensitivity is important for improving the imaging capability of CZT gamma cameras. It also allows for making more accurate corrections of response non-uniformities caused by crystal defects, thus enabling use of standard-grade (unselected) and less expensive CZT crystals for producing large-volume position-sensitive CZT detectors feasible for many practical applications. We analyzed the digitized charge signals from a representative 9 pixels and the cathode, generated using a pulsed-laser light beam focused down to 10 μm (650 nm) to scan over a selected 3 × 3 pixel area. We applied our digital pulse processing technique to the time-correlated signals captured from adjacent pixels to achieve and evaluate the capability for sub-pixel position resolution. Lastly, as an example, we also demonstrated an application of 3D corrections to improve the energy resolution and positional information of the events for the tested detectors.

Research Organization:
Brookhaven National Laboratory (BNL), Upton, NY (United States); Savannah River National Laboratory (SRNL), Aiken, SC (United States); Savannah River Site (SRS), Aiken, SC (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA), Office of Nonproliferation and Verification Research and Development (NA-22); USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
Grant/Contract Number:
SC0012704; AC02-98CH10886; AC09-08SR22470; AC02-98CH1-886
OSTI ID:
1424941
Alternate ID(s):
OSTI ID: 1415035; OSTI ID: 1430084; OSTI ID: 1582941
Report Number(s):
BNL-200012-2018-JAAM; SRNL-STI-2017-00521; SRNL-STI-2018-00073; TRN: US1801973
Journal Information:
Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 884, Issue C; ISSN 0168-9002
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 4 works
Citation information provided by
Web of Science

Figures / Tables (4)


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