Study of Multi-Pixel Scintillator Detector Configurations for Measuring Polarized Gamma Radiation

Scientific paper - Original scientific paper

• Author: Ana Marija Kožuljević
• Author: Damir Bosnar
• Author: Zdenka Kuncic
• Author: Mihael Makek
• Author: Siddharth Parashari
• Author: Petar Žugec
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

When a positron annihilates, two gamma photons are created with orthogonal polarizations. It is possible to use coincidence measurements where both photons undergo Compton scattering to estimate their initial relative polarization orientation. This information is of great interest in gamma imaging systems, such as Positron Emission Tomography, where it may be used as an additional tool to distinguish true coincidence events from scatter and random background. The successful utilization of this principle critically depends on the detector’s angular and energy resolution, which determine its polarimetric performance. In this study, we use Monte Carlo simulations based on the Geant4 toolkit to model two multi-pixel detector configurations identified as prospective for the measurement of gamma-ray polarization in PET. One is based on 2 mm × 2 mm × 20 mm LYSO scintillators and the other is based on 3 mm × 3 mm × 20 mm GAGG scintillators. Each configuration has a pair of modules, each consisting of 64 crystals set up in a single 8 × 8 matrix, where both the recoil electron and the Compton-scattered photon are absorbed. We simulate positron annihilation by generating two back-to-back gamma photons of 511 keV with orthogonal polarizations. The Compton scattering is successfully identified and the modulation of the azimuthal angle difference is clearly observed. The configuration based on GAGG crystals demonstrates slightly better polarimetric performance than the one based on LYSO crystals, reflected in the more pronounced azimuthal modulation.

• Keywords (english): gamma-ray polarization; Positron Emission Tomography; quantum entanglement; GAGG
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Condensed Matter
• Numbering: vol. 6, no. 4, 43
• e-ISSN: 2410-3896
• DOI: https://doi.org/10.3390/condmat6040043
• URN:NBN: urn:nbn:hr:217:959746
• Publication: 2021-11-16
• Project: Number: PZS-2019-02-5829; Title (croatian): Jednoslojni polarimetar gama zračenja za primjene u medicinskom oslikavanju i za temeljna istraživanja u fizici; Title (english): Single Layer Gamma-Ray Polarimeter for Medical Imaging Applications and Fundamental Physics Research; Acronym: SiLGaP; Leader: Mihael Makek; Jurisdiction: Croatia; Funding stream: Programme Research Cooperability
• Document URL: https://www.mdpi.com/2410-3896/6/4/43
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Received: 9 October 2021. Accepted: 11 November 2021. Published: 16 November 2021.
• Created on: 2024-09-14 20:43:47