Shanghai

The Shanghai synchrotron is drawing Chinese scientists back from abroad. Credit: SHANGHAI INST. APPL. PHYS.

The Shanghai Synchrotron Radiation Facility (SSRF) officially opened its doors last week to a queue of scientists waiting hungrily for beamline time. The 1.2-billion renminbi (US$176-million) light source is China's biggest investment in a single science facility to date, says Zhao Zhentang, an accelerator physicist and the facility's deputy director.

The synchrotron radiation is generated as magnets bend an electron beam around the main ring's 432-metre circumference. "It's like mud coming off a spinning tyre," says Herman Winick, assistant director emeritus of the Stanford Synchrotron Radiation Laboratory in California, and chair of the committee of 30 international and 4 Chinese scientists who last week gave the go-ahead to approve the facility's first seven beamlines.

The light ranges from high-energy, hard X-rays (10 kiloelectronvolts and above) through to infrared frequencies. It is channelled into a number of beamlines jutting out from the main ring, where it can be used for spectroscopy and diffraction experiments in fields including condensed-matter physics, structural biology and medical imaging.

In 2001, the Chinese government rejected plans for a new synchrotron light source, unconvinced that it would have enough users. Zhao and his colleagues resubmitted the proposal in June 2004 with the endorsement of scientists from more than 100 universities and some 20 institutes of the Chinese Academy of Sciences.

Since then, the project has progressed apace. Construction began on 25 December 2004, and the first synchrotron light was seen within three years, on 24 December 2007. "It's got to be a world record," says Winick. The facility is expected to have 30 working beamlines within 5 years, with the potential for up to 60 lines.

More than 60 synchrotron radiation facilities operate worldwide, with a fresh crop of cutting-edge light sources in the works (see 'Leading lights'), giving fairly routine access to scientists in most countries that invest in such research.

Before the SSRF started up, China had two light sources, in Beijing and Hefei. But these are relatively small and cannot generate hard X-rays. For many Chinese scientists, who have lacked either the funding or the visas to use facilities abroad, the SSRF is a chance to see what cutting-edge synchrotrons can do.

Zhao hopes that the investment in world-class facilities such as the SSRF will give Chinese scientists more reason to keep their research programmes in China, or to return from abroad. Indeed, Guo-Yuan Yang, a neurosurgeon who studied the mechanisms of cerebrovascular diseases for 20 years in the United States, says that he has returned to China in part because of the SSRF. Now based at Shanghai Jiao Tong University, he says the beams will allow him to examine, for example, real-time changes in small blood vessels seen in arteriovenous malformation — a circulatory disorder. "In the past we had to sacrifice animals, but here we can follow them day by day," he says.

At another SSRF beamline dedicated to X-ray absorption fine structure (XAFS), which is particularly suited to analysing the atomic structure of liquids, a group led by Guozhong Wu of the Shanghai Institute of Applied Physics is looking at the iron ion content in an ionic liquid to investigate its catalytic properties. The institute's Yuying Huang, who is in charge of the beamline, says 60 research groups from China have already requested time. "We are asking the government to build another [XAFS] line," he says.

Lili Chen of the Shanghai Institute of Materia Medica, who is using a beamline to look at the structures of complex proteins related to diabetes and other diseases, says there are already applications to use 7,000 hours of time on that beamline in 2010 — almost twice as much as has been budgeted for.

With demand that high, says Winick, "it's going to be a zoo here in a year".