Source: Pudong Observer  28^th Nov 2025

Recently, crucial phased progress has been made in the construction of the linear accelerator for the Hard X-ray Free-Electron Laser Facility (SHINE), a national major science and technology infrastructure. Its L1/BC1 section has successfully passed the beam performance process test, marking another milestone in beam commissioning following the acceptance of SHINE injector performance tests at the end of 2024.

It is reported that the expert panel for this test comprised 11 specialists from institutions including the Institute of Modern Physics of the Chinese Academy of Sciences, Peking University, Tsinghua University, and the University of Science and Technology of China. The panel listened to reports on the development of the SHINE linear accelerator L1/BC1 section and the self-test of beam parameters, and conducted on-site testing. With a measured bunch charge of 54.6 pC, the facility achieved a peak current of 56.4 A, beam energy of 273.5 MeV, normalized projected emittance of 0.54/0.34 mm·mrad (horizontal/vertical), normalized slice emittance of 0.31 mm·mrad, and a bunch repetition rate of 1000 Hz.

The test results indicate that the L1/BC1 section of the Hard X-ray Free-Electron Laser Facility has been completed and generated beam. Both the beam performance and the amplitude-phase stability of the radio frequency (RF) system meet the phased acceptance criteria. This achievement has realized the full-process verification of the overall technology of the SHINE linear accelerator, laying a solid foundation for the comprehensive completion of the subsequent facility construction.

Subsequently, the commissioning team continued its research efforts. Using a self-developed drive laser system, they completed the high-repetition-rate operation test of the injector, which met the design target of 100 pC/1 MHz, and conducted a burn-in test with stable beam output for over one hour. During the test, both the beam and all hardware systems operated smoothly.

Earlier, after seven months of intensive equipment installation, beam commissioning for the L1/BC1 section officially kicked off on August 17, with the entire beam line successfully connected on the same night. Over the following two months of intensive beam tuning, the team overcame multiple challenges posed by the simultaneous implementation of beam commissioning and hardware installation. They achieved a series of major technological breakthroughs in key areas such as large-scale cryogenic systems, integrated application of superconducting accelerating modules, and high-precision low-level radio frequency control technology. Ultimately, they successfully met all beam parameter requirements and entered the stage of stable beam operation.

The SHINE injector and the L1/BC1 section of the main accelerator form a complete superconducting linear accelerator with an energy of several hundred MeV. Its beam commissioning serves as a comprehensive verification and acceptance of the facility’s overall physical design, manufacturing of core equipment such as superconducting accelerating modules, complex electromechanical installation of equipment in underground tunnels, and integration and joint commissioning of technical systems. The success of beam commissioning has paved the way for the construction of the 8 GeV continuous-wave superconducting linear accelerator.

Located in Zhangjiang Science City, the Hard X-ray Free-Electron Laser Facility holds an important position in the global field of photon science large-scale facilities. Its construction scale and performance indicators have reached world-leading levels. once completed, it will become one of the most efficient and advanced X-ray free-electron laser facilities globally, forming a distinctive, interdisciplinary advanced scientific research platform.

Major science and technology infrastructures are crucial for seizing the commanding heights of future technological competition. In Zhangjiang, a multitude of large-scale scientific facilities are concentrated: the ultraintense and ultrashort laser experimental facility can concentrate the total solar radiation power hitting Earth onto an area as tiny as a hair strand; across the river, on Zhangheng Road in Pudong, the Shanghai Synchrotron Radiation Facility illuminates the "micron world"; nearby, the Protein Science Facility leads basic research in life sciences... These national strategic scientific and technological infrastructures are propelling Pudong to accelerate its entry into the ranks of global innovation leaders.

Data shows that during the 14th Five-Year Plan period, Shanghai’s investment in basic research increased from 12.83 billion yuan to 23.67 billion yuan, a growth of 84.5%. The city now has 15 major science and technology infrastructures either completed or under construction, with another 5 in the planning stage. Focusing on strengthening its role as a core driver of technological innovation, Pudong has gathered 1 comprehensive national science center, 3 national laboratories (bases), 14 national large-scale scientific facilities, 13 national key laboratories, 25 municipal key laboratories, 16 universities and colleges, 60 key research institutes, and 17 new-type R&D institutions, continuously boosting the construction of Shanghai’s international science and technology innovation center.

Author: Pudong Observer  From: Shanghai Observer