Soviet physicists have decided to build the most powerful particle accelerator of its kind, a straight-line facility 20 kilometers or about 16 miles long. Its length could eventually be doubled.
The device will produce head-on collisions between electrons, which carry a negative electric charge, and positrons, their positively charged counterparts. Unlike the atom-smashers of an earlier era, which were designed to break atoms into their constituents, these head-on colliders create fireballs of energy from which a variety of exotic, short-lived particles materialize.
By learning the nature of such particles, physicists hope to piece together a valid theory for the composition of matter and its behavior during evolution of the universe.
The longest such machine now operating is the two-mile Stanford Linear Accelerator in Palo Alto, Calif. A 17-mile circular machine is being built at CERN, the European research center near Geneva.
Because of energy losses inherent in circular machines, however, the CERN collider will at best achieve only 100 billion electron volts - one tenth the energy envisioned for the Soviet linear device.
A Superconducting Super Collider, a facility more than 50 miles in circumference that would collide protons accelerated to 20 trillion electron volts, has been proposed in the United States. A number of states are competing to play host to the machine.
While energies in the Stanford machine and other electron-positron colliders are less, by using beams of particles that presumably have no internal structure they lend themselves to critical experiments not possible with particles of complex composition, such as protons.
Dr. Burton Richter, director of the Stanford project, said experiments with the Stanford machine may begin next spring. …