Neutron detector can identify presence of nuclear weapons

Neutron detectors are used at border crossings and shipping ports to identify lorries and shipping containers concealing hazardous nuclear materials such as plutonium, a neutron-emitting substance that is used to make nuclear weapons.

Project leader Dr Jon Carr of Isis Innovation told The Engineer: ‘Obviously what you want is something that reacts to a neutron passing through it. You need the products of that reaction to then be picked up and then you have to pass that signal to an actual detector.’

Neutron detectors contain flourescent tubes where reactions take place. The material that reacts with the neutrons inside these fluorescent tubes is known as the scintillator. Previous neutron detectors have used Helium^-3 as the scintillator, but this element is no longer as abundant as it once was.

‘Ten years ago, Helium^-3 was a very common material because it was sourced from US military nuclear projects,’ said Carr. ‘But now these projects have finished, there isn’t a stock building up anymore.