Senior physicist Fang Shouxian vividly remembers the exciting moment marking China's first major science project in high-energy physics. October 17, 1988 was a history-making date comparable to the launch of China's first satellite. On that day, the Beijing Electron Positron Collider (BEPC) successfully staged its first experiment.
The machine is one million times more powerful than a hospital X-ray machine and allowed scientists to explore the microscopic world of electrodes. As one scientist put it, the BEPC could be used to "observe the heart of an ant".
"Everyone was applauding, and people said we Chinese eventually could feel proud among our foreign colleagues in basic science researches," recalled Fang, the former director of Institute of High Energy Physics (IHEP), which designed and built the BEPC.
In 2003, Chinese scientists used the BEPC to accurately describe the structure of SARS virus proteins and in 2004, revealed how spinach leaf molecules performed photosynthesis.
The BEPC has now finished a key renovation step. What took scientists 100 days to finish in the past will be finished in just one day.
After observing and analyzing the collision and the new particles resulting from it, physicists are able to identify many kinds of basic particles.
Quark, for example, is the component of protons and neutrons.
More than 10 years after the US and Canadian scientists used the electron positron collider in Stanford University to observe and confirm the existence of quarks, Chinese physicists began to consider the possibility of constructing an electron positron collider of their own in the late 1970s.
"The disastrous 'cultural revolution' (1966-76) was just over and many basic researches had not been resumed, so we did not expect the government to support this project," Fang told China Daily.
Unexpectedly, after hearing the proposals of leading scientists, Deng Xiaoping (190497) decided the machine was a priority.
The central government established a special steering committee, consisting of top State leaders such as Song Ping and former minister of aeronautics and astronautics Lin Zongtang. With an investment of 240 million yuan ($104.3 million at the exchange rate then), the construction of BEPC was launched in 1984.
"Song told us: 'Our purse only has a certain amount of money. But we hope you can take this precious chance and exert your biggest creation for our nation'," Fang said.
There were many technical difficulties to be solved, however, China was lucky enough to have a Nobel Prize winner to lend a helping hand.
American Chinese physicist Professor Tsung-Dao Lee, who won the 1957 Nobel Prize for physics, helped Chinese and US scientist work together.
The Columbia University professor has long been a major patron for China's international science co-operation.
"During the construction of BEPC, I could taste the great wisdom of Deng Xiaoping. The project construction not only improved the national science and technology capacities, but also promoted the close co-operation of Chinese and US scientists, playing as an important vehicle for the two nations to understand each other," Fang said.
Besides being used for observing particle collision, BEPC also provides synchrotron radiation, which is a kind of X-ray used to detect the structure of molecules.
"If an X-ray machine in hospital can clearly scan human bones, our synchrotron radiation can be used to observe the heart of an ant," said IHEP director Chen Hesheng. "Its strength is at least one million times of those used in hospitals."
Each year, BEPC was used for 10 months, five for particle collision, three for synchrotron radiation and two for equipment adjustment.
"In the West, such a big science project was operated just six months per year to ensure its stable operation," said Chen.
"But we have no other choice. It is the only such facility in China and hundreds of users line up each year to use it."
Scientists from China, the United States, Japan, South Korea and the United Kingdom have worked together to study particle collision.
The synchrotron radiation service is provided freely to users selected among hundreds of applicants.
Jin Changqing, a professor at the Institute of Physics, CAS, has studied the superconducting features of material by using synchrotron radiation of BEPC.
"We have to highly cherish the precious time (of using BEPC) by carefully designing our experiment. Each minute here cannot be wasted," he said.
In early 2004, the renovation of BEPC was launched. In five years and with an investment of 640 million yuan ($82 million), BEPC's performance will be boosted by 30 to 100 times.
The BEPC upgrade is still going on and is scheduled for completion by the end of 2008.
However, a tight schedule, much higher requirement on equipment and technologies, and the limited space to locate new facilities, all pose challenges to BEPC innovation.
"When BEPC was first constructed, we could not consider to leave larger space underground for further development. It would have needed more investment than we had," said Chen.
After repeated design, the improvements needed to boost the power were accommodated. "There was no second such design in the world," Chen said. "But compared with the innovations like the two-ring design, our biggest harvest from BEPC and its innovation is a group of innovative scientists," said Chen.