Conceptual design and simulated performance of the Barrel part of gamma array for the experimental terminal at HFRS of HIAF

• Published in: Journal of instrumentation Vol. 19; no. 5; p. T05019
• Main Authors: Li, Z.Y., Yan, D., Wang, S.T., Yu, Y.H., Sun, Z.Y., Yue, K., Tang, S.W., Zhang, X.H., Ong, H.J., Fang, F., Zhang, Y.J., Xu, X.D., Sun, Y.Z., Jin, S.Y., Ma, S.B.
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.05.2024
• Subjects: Arrays; Center of mass; Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc); Energy; Energy resolution; Gamma detectors (scintillators, CZT, HPGe, HgI etc); Gamma spectroscopy
• ISSN: 1748-0221; 1748-0221
• DOI: 10.1088/1748-0221/19/05/T05019

The Barrel of γ array, consisting of 640 CsI(Tl) crystals and covering a polar angle range from 36.4° to 135.6°, has been designed for the experimental terminals at High energy FRagment Separator of High-Intensity heavy-ion Accelerator Facility in Huizhou. Together with the existing Endcap, consisting of 1024 CsI(Tl) crystals and covering a polar angle from 15.6° to 36.4°, at the External Target Facility in Lanzhou to form a new γ array, it is expected to meet the experimental requirements for in-beam γ -ray spectroscopy technique. A Monte Carlo code based on Geant4 was implemented to study the performance of the new γ array. Taking into account the Doppler correction and the intrinsic energy resolution of the detector, the energy resolution is 5.4% (FWHM) for the Endcap and 9.8% (FWHM) for the Barrel when the energy of the emitted   γ -ray is 1 MeV in the Center-of-Mass frame with the beam energy of 500 MeV/u (beam velocity β = 0.759). The full-space photopeak efficiency is greater than 40% when the energy of the emitted γ -ray is less than 5 MeV in the Center-of-Mass frame and the beam energy is less than 700 MeV/u ( β = 0.821). Such performance can satisfy most of the physics requirements for in-beam   γ -ray spectroscopy experiments.