Use of nuclear techniques to determine the fill of found unexploded ordnance

The PELAN is a man-portable device that uses pulsed neutrons to interrogate objects in order to determine their filler. The neutrons initiate several types of nuclear reactions within the object under scrutiny, which result in the formation of gamma rays. The energy of the resulting gamma rays provides information about the elements (carbon, hydrogen, oxygen, nitrogen) contained within the object; in addition the number of gamma rays detected provides information about how much of each element is present. An analysis of the elements present and their ratios to one another allows for identification of the filler material.