Quasi-monochromatic gamma beam modulation at SLEGS

• Published in: Radiation measurements Vol. 174; p. 107127
• Main Authors: Hao, Z.R., Fan, G.T., Xu, H.H., Liu, L.X., Zhang, Y., Wang, H.W., Yang, Y.X., Jin, S., Chen, K.J., Sun, Q.K., Wang, Z.W.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2024
• Subjects: Gamma beam modulation; Gamma Modulation System; Shanghai Laser Electron Gamma Source; Gamma Modulation System; Gamma beam modulation; Shanghai Laser Electron Gamma Source
• ISSN: 1350-4487; 1879-0925
• DOI: 10.1016/j.radmeas.2024.107127

Basing on the slant Compton scattering of 10640 nm photons from a 100 W CO2 laser on 3.5 GeV electrons from the Shanghai Light Source, the Shanghai Laser Electron Gamma Source (SLEGS) produces gamma-ray in the energy range of 0.66 MeV–21.7 MeV and flux of 105–107 photons/s. A Gamma Modulation System (GMS) composed of the collimators, attenuator, beam spot imaging(MiniPIX) and flux monitor(LaBr3 detector) was developed to ensure producing bandwidth-variable quasi-monochromatic gamma-ray with a variable-flux at same time. Using the GMS, variable-flux quasi-monochromatic gamma-ray beams with a best bandwidth of 10% in the 90∘ slant-scattering and 4% in back-scattering were obtained respectively. We report on the performance of the GMS and results of gamma-ray beam modulating measurement with GMS at SLEGS. •SLEGS is a medium energy resolution slant-scattering beamline.•This article provides beam parameters for users on SLEGS.•The Gamma Modulation System(GMS) is effective in modulating gamma-ray beams.•Using the GMS, 4%–10% energy resolution can be obtained.•Flux of 105-107 photons/s can be obtained with 5 W laser power.