A new portable instrument could help to detect illicit radioactive material from a safe distance with high accuracy.
The device is designed to work at shipping ports, train stations, truck stops and anywhere that potentially concealing nuclear material could be used to make a so-called ‘dirty bomb’.
The project is being undertaken by researchers at New Hampshire University’s Space Science Center (SSC), in partnership with Michigan Aerospace.
The technology is based on a Neutron Spectroscope (Nspect) originally designed and built at the SSC for space-based missions studying high-energy neutrons and gamma rays emanating from the sun and distant astronomical objects.
Michigan Aerospace is responsible for the support engineering that will turn the benchtop instrument into a rugged field-deployable device equipped with a graphical user interface and live video-imaging capability.
‘What people have to do now is go into a building or a container and fish around in the hope of finding the source,’ said project lead James Ryan of SSC.
Indeed, current devices based on Geiger counters simply click at a higher rate the closer they are to a source of radiation and cannot filter out the ever-present background radiation. By contrast, the neutron camera records every neutron that interacts with the instrument and puts each one in a specific ‘bucket’ based on what direction that neutron came from.
The buckets are then emptied and, using software developed at SSC, the instrument focuses the neutrons into a coherent picture.
‘You need a complicated instrument that allows you to follow the neutron and give you information about its velocity and the direction it’s coming from,’ said Ryan.
‘Our instrument will be very sensitive and, when it detects these neutrons, it will be able to construct images of the emission pattern and report the neutron spectrum, which, in turn, will allow us to nail down what type of nuclear material we’re dealing with.’