U.S., China Cooperate on High-Energy Physics Experiment

By Jade Boyd

With $5 million in new U.S. funding and a $2 million commitment from the Chinese Academy of Sciences, Rice University physicists are organizing the joint U.S.–Chinese production of an innovative set of detectors for one of the Department of Energy’s premier particle accelerators, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) on Long Island, New York. The project represents the most significant collaboration to date between the United States and China in high-energy particle physics detector research.

“Particle physics provides a clear example of the need for increased cooperation in science today because no single institution—indeed, no single nation—can afford the apparatus or command the expertise required to advance the boundaries of physical knowledge in this arena,” says Rice University president David Leebron. “This program is an example of the most robust scientific cooperation, the type that emerges when scientists meet and collaborate on important areas of mutual interest and concern.”

STAR TOF project manager Geary Eppley, a physicist in Rice’s Bonner Lab, tours high-energy physics research facilities in China.

Over the next three years, the international team, which is managed by Rice’s T.W. Bonner Nuclear Laboratory, will build, install, and test a cylindrical bank of more than 23,000 particle detectors in the Solenoidal Tracker at RHIC (STAR). “Physicists at the Bonner Lab first proposed a system like this 15 years ago,” says lab director Billy Bonner, a co-principal investigator on the grant, “but the cost of the detectors alone was estimated at $12 million, so we went back to the drawing board and came up with a less expensive design. Without our Chinese partners, this new system wouldn’t have been feasible. Their detectors are superior in quality to any of the prototypes we created, and their support and enthusiasm for the project are unparalleled.”

The STAR Time-of-Flight (TOF) detectors will allow physicists to help distinguish types of subatomic particles from one another after they are created in head-on smash-ups between protons and neutrons, giving physicists a brief glimpse of some of the basic constituents of matter.

“Producing the detectors is a huge undertaking, and the U.S. partners will wind up making more than 2,300 electronic boards for the system,” says STAR TOF project manager Geary Eppley, a research scientist at the Bonner Lab. “Assembly and testing will take place at the University of Texas at Austin (UT), and we’ll install as many detectors as we can each summer when RHIC is shut down. We expect to finish in 2009.”

Participating institutions include Rice, BNL, UT, the University of California at Los Angeles, the Institute of Particle Physics at Wuhan, the Institute of Modern Physics at LanZhou, the Shanghai Institute of Applied Physics, Tsinghua University in Beijing, the University of Science and Technology of China at Hefei, and the Institute of High Energy Physics in Beijing.