They are one invention envisioned by researchers at the Lawrence Livermore National Laboratory (LLNL) who have founded the Radiation Detection Center (RDC) to help counter nuclear terrorism. "The Center leverages our past work in radiation detection for today's security needs, including the detection, identification, and analysis of nuclear materials and devices," says Simon Labov, director of RDC. According to Labov, detection sensitivity is one of the focal points for the Center.

In this regard, RDC researchers are developing RadNet, a cellular telephone-based radiation detection network. It's based on small detector units that will feature the capabilities of a cell phone, radiation sensor, PDA, Internet access, and GPS. Each unit contains enough energy resolution to distinguish between different types of radioactive materials, such as medical isotopes, industrial sources, and "dirty bomb" materials. Prototypes are expected within a few months.

On another front, an ultrahigh-resolution gamma-ray spectrometer called Ultra-Spec precisely measures gamma rays from nuclear materials. Operating within one degree of absolute zero, the instrument records the change in temperature, or warming, when a single gamma ray hits its superconducting material, which is usually tin. Ultra-Spec will be able to isolate emissions from different types of radioactive materials to more easily identify their exact composition. The first prototype has already been produced.

A Gamma Ray Imaging Spectrometer is one of five gamma-ray imaging systems under development by LLNL researchers. The device takes snapshots of radioactivity emissions in large areas. "Recent advances in microelectronics let us build a gamma-ray camera that consists of many gamma-ray sensors all working together," says Labov. The device is about the size of a large-screen TV, and is perhaps a year away.