Conceptual design of a gamma-to-electron energy-selective imaging system for high-flux MeV gamma rays

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Vol. 1068; p. 169742
• Main Authors: Zhang, Changqing, Sheng, Liang, Song, Zhaohui, Da, Tianxing, Li, Haoqing, Duan, Baojun, Li, Yang, Hei, Dongwei, Wang, Qunshu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2024
• Subjects: Electromagnet; Energy-selection; Gamma-ray imaging; Geant4 simulation; Ion optics; Electromagnet; Geant4 simulation; Energy-selection; Ion optics; Gamma-ray imaging
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2024.169742

A novel design for energy-selective imaging of high-flux gamma rays in the multi-MeV range is presented. The proposed system is based on gamma-to-electron conversion and energy-selective imaging of the electrons. The main components of the system include a low-Z foil that converts MeV gamma-ray photons into electrons through Compton scattering, and a double-bend beam transport system that performs energy selection and point-to-point imaging for the electrons. The image of the energy-selected electrons can be used to obtain spatial information for incident gamma rays of interest energy, enabling energy-selective imaging of broad-spectrum gamma-ray beams. Design considerations and optimizations are detailed. Monte Carlo simulations are conducted to evaluate the performance in energy-selective imaging of broad-spectrum gamma-ray beams. The energy resolution for 4.44 MeV gamma-ray achieves 0.41 MeV (FWHM) with a quantum efficiency of 2.5 × 10−6 e/γ, and the spatial resolution is approximately 1 mm and 2.5 mm within a 60 × 60 mm field of view in the horizontal (x) and vertical (y) directions, respectively. •A novel design for gamma-to-electron energy-selective imaging of high-flux gamma rays in the multi-MeV range is presented.•The energy resolution for 4.44 MeV gamma-ray achieves 0.41 MeV (FWHM) with a quantum efficiency of 2.5 × 10−6 e/γ.•The spatial resolution is approximately 1 mm within a 60 × 60 mm field of view.