As researchers continue to grapple with the problem of how to detect smuggled nuclear material, one of the latest efforts surfaced recently at Sandia National Laboratories. Scientists there have developed a neutron scatter camera they say may be able to detect radiation faster from much greater distances than current detection instruments.

Sandia physicist Nick Mascarenhas told Homeland1 that while neutron detection is not very refined at present, the Sandia device is state-of-the-art. "It can pinpoint precise source location and yield information on the source energy spectrum."

Mascarenhas said the neutron scatter camera has the ability to count neutrons from a radiation source and then localize that source. This means it can not only indicate that radiation is present, but also where the radiation is emanating from and, under some circumstances, how much radiation there is.

Such a device would have immediate application in homeland security. Since 9/11, radiation detection has been an urgent priority, as a means of preventing a domestic nuclear weapon attack. Gamma ray and neutron detectors are being deployed at border crossings and ports, with the goal of enabling interdiction of a nuclear weapon or material before it enters the country.

Mascarenhas sees the Sandia neutron scatter camera being used in the field by agencies such as the Department of Homeland Security, the Defense Threat Reduction Agency, and Customs and Border Protection. “This device could be used in cargo searches, at border crossings, or in maritime and aviation applications” he said.

Neutron scatter camera technology has an advantage over traditional neutron detection because it can differentiate low-energy from high-energy neutrons. The scatter camera doesn’t pick up low energy nuisance neutrons from cosmic radiation that are always all around us, because it's designed to see only high-energy neutrons.

It also has the ability to neutralize shielding. While some gamma rays can be blocked from detectors, neutrons are much more difficult to conceal. In a lab test, the camera easily detected and imaged a source placed across the hallway, through several walls and cabinets, Mascarenhas said.