Beijing, this "magnifying glass," is as large as 90 football fields!

Release time:

2025-09-01 15:42

From a high-altitude view of Huairou Science City, a building shaped very much like a handheld magnifying glass stands out prominently; it is the National Major Scientific Infrastructure High Energy Photon Source (HEPS).

△ High Energy Photon Source

A major national instrument resembling a "magnifying glass"

Huairou Science City is located by Yanqi Lake. Beijing Youth Daily reporters noticed that there are three main buildings within the High Energy Photon Source park, full of futuristic design. From the model, it is visually clear that the overall shape of the building resembles a magnifying glass, with the "handle" area being the comprehensive laboratory and user service building, and the "frame" area being the photon source device zone.

According to Pan Weimin, a researcher at the Institute of High Energy Physics, Chinese Academy of Sciences, and chief commander of the HEPS project, the building covers 976 mu, equivalent to the size of 90 football fields. The "frame" of the magnifying glass is a ring-shaped building with a circumference of over 1,300 meters. Walking along the outer ring road takes twenty to thirty minutes. "To improve work efficiency, staff sometimes ride bicycles inside the photon source device experimental hall."

It is understood that the High Energy Photon Source is a national major scientific infrastructure prioritized during China's 13th Five-Year Plan. Once completed, the facility will better meet research needs in cutting-edge scientific and engineering applications such as aerospace, energy and environment, and biomedicine, becoming an internationally leading high-energy photon source experimental platform.

△ High Energy Photon Source

Successfully emitted the "first beam of light"

The HEPS project started construction in June 2019 with a construction period of six and a half years. Once completed, it will be the world's highest brightness fourth-generation synchrotron radiation source and China's first high-energy photon source.

Over more than five years, the project has continuously achieved phased results. On June 28, 2021, the first scientific research equipment was installed; on March 14, 2023, the linear accelerator reached full energy beam output; on July 1, 2024, the storage ring was fully connected and entered the joint debugging phase. So far, the construction of the accelerator and the first batch of beamline stations has been completed.

On October 12, 2024, the "first beam of light" was successfully emitted. That evening, Dong Yuhui, the executive deputy commander of HEPS, led the team to hang an orange film at the light exit. After adjusting the film position, they left the experimental station, closed the radiation protection door, pressed the button, and opened the light shutter.

After closing the light shutter, the indicator light on the experimental station door changed from red "No Entry" to green "Entry Allowed." When the team re-entered the station, a neatly edged black spot appeared on the orange film. This is the mark left by the first beam of light emitted by HEPS. Dong Yuhui also recorded this precious moment on it: "2024.10.12 21:30" "Exposure 0.1s (seconds)".

Pan Weimin told Beijing Youth Daily reporters that since the light emitted by the device is not visible light, the human eye cannot directly perceive its existence. "The synchrotron radiation source is equivalent to a giant X-ray machine, capable of detecting cracks in aerospace materials during processing and service, and can also observe cellular molecular structures."

Nanjing Expansion Technology contributes to the "national major instrument"

By Nanjing Expansion Technology The tunnel environment test system constructed by Nanjing Expansion Technology is the infrastructure for the HEPS Test Facility (HEPS-TF). It will provide essential experimental environment and space for key technology research of HEPS-TF. The construction and implementation of this project system recognize our company's capability in building ultra-high precision constant temperature and humidity clean systems and the professionalism of our technical research and development.

The technical features of this system are high-precision temperature control and temperature fluctuation simulation, which can provide effective data support for the later main tunnel environment construction of the "Beijing Photon Source."

The system's maximum temperature fluctuation can reach ±0.01℃, providing reliable assurance for experimental data validation.

The system can also simulate temperature fluctuations from ±0.1℃ to ±3℃, allowing verification of the impact of temperature accuracy on experimental results through temperature fluctuation simulation.

Entering the open sharing phase in the future

To date, China's synchrotron radiation sources have developed for nearly 40 years, from the first-generation Beijing Electron-Positron Collider's shared Beijing Synchrotron Radiation Facility, the second-generation dedicated Hefei Light Source, the third-generation Shanghai Light Source, to the fourth-generation High Energy Photon Source.

Why is the fourth-generation high-energy photon source needed? Pan Weimin explained that each generation has improved brightness indicators. The first-generation source resolved the molecular structure of the SARS virus in 2003, The fourth generation will "illuminate" the nanoscale, more complex microscopic world. "To see details inside matter, a very important point is to have sufficiently bright light. The brighter the light, the higher the signal-to-noise ratio of detection, the higher the precision, and the faster the detection speed. The brightness of the fourth-generation synchrotron radiation source is ten trillion times that of a chest X-ray machine," said Pan Weimin. Currently, researchers have already conducted related experiments using the "first beam of light" emitted by HEPS, "The observed samples are clearer, and some cracks in aerospace materials are judged much more clearly than with other light sources."

From the perspective of providing X-ray energy, synchrotron radiation sources mainly have three energy ranges: low, medium, and high energy sources. The first phase of HEPS construction includes 14 user beamline stations and 1 test beamline station. Among them, the Hard X-ray Imaging beamline (HXI) is one of the featured stations, providing highly spatially coherent high-energy X-rays.

According to reports, preliminary experimental results show that Compared with conventional sources, the HXI beamline's light penetrates deeper, has higher resolution, significantly improved sensitivity, a notable increase in detectable cracks, and greatly enhanced imaging contrast. The HXI beamline can achieve previously difficult-to-combine features: strong penetration and high sensitivity, large field of view and high-resolution X-ray imaging, providing strong scientific research support for frontier fields such as aerospace engineering materials research and whole-brain mesoscale 3D imaging.

On March 27 this year, HEPS announced the start of beamline joint debugging. So far, four rounds of beamline joint debugging have been completed, with multiple beamline stations conducting featured sample experiments. The next step is to continue debugging work, ultimately achieving project acceptance criteria and entering the open sharing phase.

Some content sourced from: Beijing Youth Daily (June 20, 2025, Page A03)

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