China is set to fire up a powerful new x-ray light source that will reveal the atomic-scale structure of proteins and materials. By the end of December, operators expect light to begin to stream into experimental beamlines at the High Energy Photon Source (HEPS) near Beijing, which will become one of just a handful of “fourth-generation” synchrotrons in the world.
HEPS revs electrons up to high energies and bends them around a circular track so the particles emit synchrotron radiation—mostly short-wavelength “hard” x-rays. The intense, laserlike x-rays are siphoned off into 14 beamlines that scientists will use to image materials and biological structures at atomic to nanometer scales and take snapshots of chemical reactions over nanosecond time frames.
“It’s like getting a major new telescope. You can see things that were not observable before,” says Mingda Li, who studies the quantum properties of materials at the Massachusetts Institute of Technology and chairs the users’ executive committee for the Advanced Photon Source (APS), a U.S. Department of Energy synchrotron at Argonne National Laboratory. “This is a very exciting time for the synchrotron community.”
In structural biology, for example, HEPS will allow scientists to study cellular machines, such as the protein-assembling ribosome, in addition to imaging whole cells and viruses. “We’ll be able to see the protein machines in their natural environment, at high resolution,” says Dong Yuhui, deputy director of the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences, which will operate HEPS. The big challenge, Dong says, will be managing “the huge data” such experiments generate.
IHEP first proposed HEPS in 2008 and 10 years later began to build the 4.76 billion renminbi ($657 million) complex. The IHEP team is now waiting on final review—and an operating license—from HEPS’s funder, China’s National Development and Reform Commission. Following first light into the beamlines for a handful of in-house scientists in late December, the HEPS users committee will issue a call for experiments from the broader research community. Dong hopes the call can proceed by late January 2025. “Then everybody will be happy.”
Competition for beam time is expected to be fierce. For instance, only about one in five proposals makes the cut at APS. After completing upgrades and turning on its beamlines in June, APS became the first fourth-generation light source in the United States. “HEPS will have a similar quality beam and be competitive with the upgraded APS,” says Eric Isaacs, a condensed matter physicist and former director of Argonne. “They are both great machines.”
HEPS is the first fourth-generation synchrotron in Asia. Next up could be the SPring-8 synchrotron, a facility Japan will start to upgrade next year, with plans to transform it into SPring-8-II by 2029. The aim is to dial up SPring-8’s brightness more than 100 times, making it the world’s most powerful synchrotron. HEPS, meanwhile, won’t be resting on its laurels. IHEP plans to add another 30 to 32 more beamlines over the next 5 years, Dong says.
