Evaluation of a SiPM array coupled to a Gd3Al2Ga3O12:Ce (GAGG:Ce) discrete scintillator. Issue 7 (November 2015)

• Record Type: Journal Article
• Authors: David, S.; Georgiou, M.; Fysikopoulos, E.; Loudos, G.
• Is Part Of: Physica medica. Volume 31:Issue 7(2015)
• Page Start: 763
• Page End: 766
• Publication Date: 2015-11
• Subjects: GAGG:Ce -- Silicon photomultipliers (SiPMs) -- PET; Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2015.03.008
• Languages: English
• ISSNs: 1120-1797

Abstract

Abstract: Purpose: In this study, we present the results of the evaluation of the SensL ArraySL-4 photo-detector, coupled to a 6 × 6 GAGG:Ce scintillator array, with 2 × 2 × 5 mm 3 crystal size elements for possible applications in medical imaging detectors with focus in PET applications. Experimental evaluation was carried out with 22 Na and 137 Cs radioactive sources and the parameters studied were energy resolution and peak to valley ratio. Methods: ArraySL-4 is a commercially available, 4 × 4 array detector covering an active area of 13.4 mm 2 . The GAGG:Ce scintillator array used in this study has 0.1 mm thickness BaSO4 reflector material between the crystal elements. A symmetric resistive voltage division matrix was applied, which reduces the 16 outputs of the array to 4 position signals. A Field Programmable Gate Array was used for triggering and digital processing of the signal pulses acquired using free running Analog to Digital Converters. Results: Raw images and horizontal profiles of the 6 × 6 GAGG:Ce scintillator array produced under 511 keV and 662 keV excitation are illustrated. Moreover, the energy spectra obtained with 22 Na and 137 Cs radioactive sources from a single 2 × 2 × 5 mm 3 GAGG:Ce scintillator are shown. The peak to valley ratio and the mean energy resolution values are reported. Conclusions: The acquired raw image of the GAGG:Ce crystal array under 511 keV excitation shows a clear visualization of all discrete scintillator elements with a mean peak to valley ratio equal to 40. The mean energy resolution was measured equal to 10.5% and 9% respectively under 511 keV and 662 keV irradiation. Highlights: GAGG/SιPM array detector development for PET. Energy resolution was measured equal to 10.5% and 9% under 511 keV & 662 keV respectively. The mean peak to valley ratio measured very high equal to 40. Possible application for dual SPECT/PET hybrid detector.