At the Gammasphere nuclear frontier - highly sensitive nuclear detector at Lawrence Berkeley National Laboratory - Physics - Brief Article

Science News, July 13, 1996

Researchers are now starting to take advantage of a new, highly sensitive instrument for detecting gamma rays emitted by atomic nuclei. Located at the Lawrence Berkeley (Calif.) National Laboratory and known as Gammasphere, this nuclear detector consists of a metal sphere more than 2 meters wide, honeycombed with 110 individual sensors.

The array enables physicists to study gamma rays from atomic nuclei created in high-energy collisions that fuse different ions together. These fused nuclei typically spin at high rates and often assume unusual shapes, ranging from football to pancake forms (SN: 7/8/95, p. 21).

A team led by Cyrus Baktash of the Oak Ridge (Tenn.) National Laboratory has now detected examples of short-lived, rapidly rotating, football-shaped nuclei among the elements strontium, yttrium, zirconium, and niobium. "They are the fastest-spinning nuclei yet observed," Baktash says. The nuclei were synthesized by bombarding a nickel-58 target with beams of silicon-28 or sulfur-32 ions.