| 摘要 |
A system for detecting the presence of a given substance, such as an explosive or a narcotic substance, within a monitored object (16), such as luggage, includes an X-ray scanning system (10); a prompt gamma neutron activation analysis (PGNAA) scanning system (12); a conveyor (14) for transporting a monitored object through the X-ray scanning system and the PGNAA scanning system. The X-ray scanning system provides X-ray data signals (26) in response to X-ray scanning of the transported monitored object. The neutron analysis scanning system provides neutron analysis data signals (28) in response to PGNAA scanning of the transported monitored object. A data processing system (30, 32) processes the X-ray data signals and/or the neutron analysis data signals to provide an indication as to whether the transported monitored object contains at least a predetermined amount of a given substance. Both the X-ray scanning system and the PGNAA scanning system are contained within a common housing (18) having common radiation shielding material (20) positioned for shielding persons and objects outside the housing from both X-rays and radiation generated by the neutron analysis scanning system. The data processing system generates discriminants from the X-ray data signals and the neutron analysis data signals and conditions a neural network with the discriminants so that X-ray data signals and the neutron analysis data signals for monitored objects having unknown contents can be processed in accordance with the neural network to determine whether at least a predetermined amount of the given substance is contained within the monitored object. <IMAGE> |
