In this scene from the movie, the Hulk lifts up the Gammasphere. Photo courtesy of Universal Studios.

An unlikely supporting actor in the new Sci-Fi thriller The Hulk is a 14-ton nuclear physics device called Gammasphere from Argonne National Laboratory. In the movie, Gammasphere bombards scientist Bruce Banner with radiation, turning him into a towering, green powerhouse. In reality, the instrument is the world's most sensitive gamma-ray microscope used for detecting, not producing, gamma rays. The 10-ft-tall silvery machined-aluminum sphere is mostly used by scientists to study atomic nuclei, often concentrating on nuclei forms with excessive protons and neutrons.

The sphere, about 7 ft in diameter, is pierced by 110 holes holding yard-long gamma-ray detectors that meet near the sphere's center. Liquid nitrogen cools the detectors to -320°F, making them more sensitive. Beams of ions from the Argonne Tandem Linac Accelerator System (a superconducting accelerator for subatomic particles heavier than electrons) hit a target in the Gammasphere's center, where some of the nuclei from the beam fuse with nuclei in the target. The resulting gamma rays tell scientists about the structure and forces inside atomic nuclei. Physicists also hope to learn if isotopes with unusual neutron-to-proton ratios have different characteristics than stable nuclei.