HIT DETECTION OF FAST MOVING RADIOACTIVE SOURCES

The sensitivity of detection systems to passage of radioactive sources can be increased through larger detectors, higher resolution of the detectors, or suppression of background counts. An additional method to detect the passage of a fast moving radioactive source is by using the difference in count statistics between background alone and background and the moving source. This method allows the detection of very low count sources, with a very low level of false alarms due to background fluctuations. This method is enhanced through the use of multi-channel analyzers capable of timing pulse arrivals to within 1 µs. The use of various correlation techniques allows the detection of source strengths of tens of µCi moving at highway speeds.