radiation. exposures to the aircrews as they returned to base, to decontamination ground crews. as well as The samples collected were radiologi- cally “hot" and required special handling as they were taken from the aircraft and prepared for shipment to the laboratory for analysis. DIAGNOSTIC MEASUREMENTS. The explosion of a nuclear device is a pro- gressive release of increasing amounts of nuclear radiation, some of which directly escapes the device. The rest of the radiant energy interacts with the associated material of the device itself and is converted into differing forms of radiation and into the kinetic energy of the remaining materials in a small fraction of a second. The intensely hot core then reradiates, heating the surrounding air and creating a shock wave that propagates Outward from the burst point. The weapon diagnosticians used sophisticated techniques to follow the Processes that occur during the device explosion. Detectors and collec- tors were run up to, and sometimes inside, the device case so that the radiation being sampled could be directly channeled some distance away and there be recorded by instrumentation designed to survive the ensuing blast. To enhance its transport, radiation was conducted through pipes evacuated or filled with special gases) (often from the device to stations where recording instrumentation was located or where the information could be retransmitted to a survivable recording station. Radiation measurements are based upon the effects that result from the interaction of the radiation with matter. Fluorescence is one such effect. Materials that fluoresce with radiation exposure were placed in view of cameras or light detectors to provide a record of the variation of fluorescent intensity with time, thereby providing an indirect measurement of the radiation environment. Other methods of detecting radiation tion) properties of earth materials, materials are also used to baffle or involve water, the shielding (attenua- and other substances. These collimate radiation to ensure that radiation is directed toward the detecting instrument. 33