WASHINGTON'A group of physicists is recommending that the United States help build a large new particle accelerator as the next big step to understanding the basic building blocks and forces in the universe.
The group estimates the new machine, a linear collider roughly 18 to 20 miles long, would lost from $5 billion to $7 billion. It would collide electrons and their anti-matter counterparts, called positrons. The costly machine will require international collaboration, the group said, much as is happening at a circular collider, 16.6 miles in circumference, now being built in an existing tunnel at CERN, the European particle physics laboratory near Geneva.
There is an international consensus on the need for a next-generation linear machine to complement the research scheduled to get under way at the new CERN machine in 2006, physicists said this week at a meeting here of the Department of Energy's High Energy Physics Advisory Panel.
A subgroup of the panel delivered a 20-year road map for U.S. high-energy particle physics, including the call for support of the linear collider. It said more research and development will be required before the United States can mount a bid to host the machine, which also is being sought by Germany and Japan. Physicists also must sell the machine to Congress and the broader scientific community.
\We need to bring forward a project that is supported by the entire scientific community,' said Jonathan Bagger of Johns Hopkins University, co-chair of the subgroup.
If the proposed particle accelerator is built in the United States, the report said, it will require spending a total of 30 percent more on the nation's high-energy physics program over the next 20 years. One-third of the financing for the machine would come from international partners.
