Study of sub-pixel position resolution with time-correlated transient signals in 3D pixelated CdZnTe detectors with varying pixel sizes
- Pennsylvania State Univ., University Park, PA (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- University of Texas, El Paso, TX (United States)
- Pennsylvania State Univ., University Park, PA (United States)
- 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
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