ITHACA, N.Y. - The Cornell Electron Storage Ring (CESR) on the Cornell University campus is one of only 10 such particle accelerators in the world, and one of only four in the United States. And it is the only accelerator in the world that functions simultaneously as a source of particles that bring matter and anti-matter into collision - a key to understanding the makeup of the universe - and as a source of one of the most intense X-ray beams produced anywhere.

During September, CESR will be shut down for annual maintenance. It will be a rare opportunity for visitors to see the inner workings of the half-mile-circumference particle racetrack, located in a tunnel 40 feet below Cornell's athletic fields.

EDITORS: To recognize the 20th anniversary of its scientific program and to offer the public a glimpse of its ongoing research, the Wilson Laboratory, which houses CESR, is available for tours by the news media during the week of Sept. 25. Media representatives will be taken on a tour of the underground tunnel and provided with clear descriptions of research being undertaken by international teams of scientists using the accelerator. There will be many unusual picture opportunities.

On hand for scheduled interviews will be noted accelerator physicist Maury Tigner, who this year took over the directorship of the Laboratory of Nuclear Studies, one of the world's leading centers for elementary particle research and the operator of CESR. Tigner helped design and build CESR 20 years ago. Other senior CESR scientists also will be available.

One of the remarkable aspects of the research in Wilson Lab is that the length of scales being investigated range from the sub-atomic to the astronomical - in the sense of exploring the makeup of the universe. Both the smallest and largest scales are the domain of a particle detector called CLEO, which involves a collaboration of 26 institutions, including the University of Rochester, Syracuse University and the State University of New York at Albany. The intermediate-length scales (atomic to human) are the realm of the Cornell High-Energy Synchrotron Source, or CHESS, which uses the intense X-ray beams generated by CESR for research into such areas as electronics, pharmaceuticals and biological systems.

To arrange for an individual media tour of CESR during the week of Sept. 25, please contact Ahren Sadoff, visiting professor of physics, at Wilson Lab at 607-255-4882 or AJS@LNS62.LNS.CORNELL.EDU.