Gamma rays are at the high energy end of the electromagnetic spectrum. Each gamma ray photon carries from thousands to millions of times more energy than a photon of visible light. Their high-energy means gamma rays are not easily scattered or destroyed and makes them highly valuable for observing a wide variety of nuclear and astrophysical phenomena that could not otherwise be studied.

The world's most powerful instrument for detecting gamma rays is called "Gammasphere." Designed and built at Berkeley Lab, it features a honeycomb array of high-resolution germanium crystal detectors and bismuth-germanate scintillation counters that make it a hundred times more sensitive than any of its predecessors.

Gammasphere provides scientists with a unique window in space and time through which they can observe the gamma rays emitted by rapidly spinning "superdeformed" atomic nuclei. These nuclei arise for the briefest of instants (50 trillionths of a second) out of the collisions that take place inside particle accelerators. They may also be common to exotic objects in the cosmos such as white dwarfs and neutron stars. Scientists are studying superdeformed atomic nuclei to learn more about nuclear interactions and decay. This information in turn can provide insight into how conventional nuclei are formed.

Gammasphere was built with the active participation of scientists at a number of other institutions including Argonne, Lawrence Livermore, and Oak Ridge National Laboratories. Currently housed in an area adjacent to the 88-inch cyclotron, Gammasphere is scheduled to move to Argonne in September of this year. It is expected to reside there for a year or more before returning to Berkeley Lab.