DETECTION SYSTEM FOR EXPLOSIVES

摘要

To detect if an article (30) contains explosive (31), the article is passed adjacent a source (22) of neutrons and an array of gamma ray detectors (21). Neutrons (32) from the source (22) generate gamma rays (33) in the explosive (31) , due to its high nitrogen content, and those gamma rays (33) are detected by the detectors (21). An analysis system is provided which analyses the outputs of the detectors (21) in a series of time intervals so that the article (30) is analysed in a series of windows and from this high nitrogen areas can be detected. These windows extend along the article (30) in the direction of its movement due to transportation by e.g. a conveyor (20) and also transversely by providing an array of the detectors (21) arranged transversely to the conveyor (20).