New SSRF Facility: Laser Electron Gamma Beamline SLEGS

Commissioning of laser electron gamma beamline SLEGS at SSRF

Hong-Wei Wang ^1,2,3 Gong-Tao Fan ^1,2,3 Long-Xiang Liu ^1,2 Hang-Hua Xu ^1,2 Wen-Qing Shen^1,2,3

Yu-Gang Ma ^2,4,6 Hiroaki Utsunomiya^1,5 Long-Long Song ¹ Xi-Guang Cao^1,2,3 Zi-Rui Hao ^2,3

Kai-Jie Chen ^2,6 Sheng Jin 2,3 Yu-Xuan Yang ^2,7 Xin-Rong Hu ^2,3 Xin-Xiang Li ^2,3 Pan Kuang ^2,3

1. Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China；

2. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China；

3. University of Chinese Academy of Science, Beijing 100049, China；

4. Fudan University, Shanghai 200433, China；

5. Department of Physics, Konan University, Kobe 658-8501, Japan；

6. ShanghaiTech University, Shanghai 201210, China；

7. Zhengzhou University, Zhengzhou 450001, China

Vol.33, Issue 7, Article number:87 (2022)

DOI：10.1007/s41365-022-01076-0

Plain Language Summary Research Story DOI：https://doi.org/10.11889/nst.33.7.87

The Novelty

The state-of-the-art Shanghai Laser Electron Gamma Source (SLEGS) has officially completed its commissioning which lasted from July to December 2021. Other than a back-scattering mode, for the first time, a slant-scattering mode is adopted in the SLEGS beamline to generate powerful quasi-monoenergetic gamma-ray beams systematically. With an energy spread of 2 – 15 %, a gamma-ray beam with energy ranging from 0.25 to 21.1 MeV in slant-scattering at collision angles ranging from 20 – 160° is generated. In back-scattering at 180°, the beam achieves maximum energy of 21.7 MeV. Notably, a 2 % energy resolution can achieved with a 1-mm or smaller collimator. The SLEGS beamline primarily comprises four components: i) a 100-W CO2 laser and laser transport; ii) an interaction chamber (slant-scattering) and a multi-function chamber (back-scattering); iii) two-stage coarse and fine collimators and a gamma flux attenuator; and iv) an experimental hutch, an experimental detector, a gamma absorber, and a data acquisition system. In order to establish a more in-depth understanding of the energy resolution, more realistic Geant4 simulations can be deployed to carry out a thorough analysis in the future.

The Background

The laser Compton scattering (LCS) gamma source is currently the most advanced quasi-monoenergetic gamma-ray source supporting photonuclear physics research. Meanwhile, slant-scattering is an essential technology to produce gamma-ray beams with tunable energy at synchrotron radiation facilities which operate at fixed electron beam energy. Hence, in an attempt to establish a world-class high-energy laser electron gamma source, scientists in China have recently commissioned the Shanghai Laser Electron Gamma Source (SLEGS) which adopt both slant- and back-scattering mode to yield MeV gamma-ray beams. By doing so, a new milestone has been achieved by the Shanghai Synchrotron Radiation Facility (SSRF) for having a total of 16 beamline stations in its Phase II Project. With the readiness of SLEGS in facilitating both basic and applied research in nuclear physics, scientists will have more space and opportunity to contribute to the advance of the nation’s nuclear technology.

The SDG Impact

To-date, the number of facilities with high-energy laser electron gamma sources dedicated to nuclear science studies remains scanty globally. Since SLEGS is a high-potential multi-functional experimental platform, the addition of SLEGS to the Shanghai Synchrotron Radiation Facility will be of significant impact to the expansion of nuclear research, especially in China. By supporting the advancement of nuclear technology, this study shows good alignment with United Nations Sustainable Development Group (UNSDG) 9: Industry, innovation & infrastructure.

Graphical Abstract