A γ-Ray Detector Based on a 3" LaBr3:Ce:Sr Crystal With SiPM Readout for 80 keV-16 MeV Energy Range With Position Sensitivity for Doppler Correction

• Published in: IEEE transactions on nuclear science Vol. 70; no. 10; pp. 2337 - 2343
• Main Authors: Agnolin, Marco, Di Vita, Davide, Borghi, Giacomo, Carminati, Marco, Camera, Franco, Wieland, Oliver, Million, Benedicte, Giaz, Agnese, Mihai, Constantin, Turturica, Andrei, Costache, Cristian, Borcea, Ruxandra, Soderstrom, Par-Anders, Ban, Rebeca Sara, Fiorini, Carlo
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adaptive control; Algorithms; Application specific integrated circuits; Boron; Cesium 137; Cesium isotopes; Cesium radioisotopes; Crystals; Detectors; Deuterium; Doppler correction; Doppler effect; Dynamic range; Energy; Energy resolution; Gain control; Gamma ray spectrometers; Gamma rays; Integrated circuits; Lanthanum; lanthanum bromide; Lead; Machine learning; Nuclear physics; Photomultiplier tubes; Physics; relativistic Doppler broadening; Relativistic effects; Relativistic velocity; scintillators; Sensitivity; Sensors; silicon photomultipliers (SiPMs); Spatial discrimination; Spatial resolution; γ Radiation
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2023.3312424

We report the validation in an extended energy range (80 keV-<inline-formula> <tex-math notation="LaTeX">\simeq 16 </tex-math></inline-formula> MeV) of the GAMMA detector, a high-dynamic range, high-resolution, gamma-ray spectrometer for nuclear physics applications based on a 3 co-doped lanthanum bromide (LaBr3:Ce:Sr) crystal (73 ph/keV conversion efficiency, 25 ns decay time) coupled to 144 NUV-HD silicon photomultipliers (SiPMs). The detector shows state-of-the-art energy resolution along the entire range thanks to the automatic gain switching feature [adaptive gain control (AGC)] of the custom application-specific integrated circuits (ASICs) employed in the system. To the best of our knowledge, this is the first time that SiPMs have been used to measure such high energy together with a wide dynamic range and excellent energy resolution (2.7% at 662 keV). In addition, the pixelated nature of the SiPMs detectors, combined with machine learning (ML) algorithms, can be exploited to reconstruct the position of the first interaction of the gamma rays inside the scintillation crystal. Previous measurements with a 137Cs collimated source have achieved a spatial resolution better than 2 cm. This performance in position sensitivity has been used to compensate for the relativistic Doppler broadening effects of gamma rays at 15.110(3) MeV emitted by a carbon nucleus moving at relativistic speed (v/c <inline-formula> <tex-math notation="LaTeX">\simeq ~0.05 </tex-math></inline-formula>) resulting from a boron-on-deuterium reaction, improving the FWHM resolution of the peak by 15%, which is in agreement with the theoretical expectation.