MEASUREMENT OF THE RADIONUCLIDE CONTENT OF AIRBORNE PARTICLES, 1964-1965

摘要

The radionudide content of airborne particles at Cincinnati, Ohio, is being measured by gamma spectral analysis. The content of several thousand cubic meters of air is collected daily or weekly on filters with high-volume samplers. Characteristic gamma rays emitted by the radionudides on the particles are detected with a NaI(Tl) crystal and recorded according to energy by a 200-channel spectrometer. A number of computer programs provide simple and difference analyses of radionudide mixtures and report radionudide concentrations and counting errors. Throughout the two years of measurement, concentrations for the following 6 major radionudide groups were routinely obtained: ~(144)Ce-~(144)Pr, ~(106)Ru-~(106)Rh, ~(137)Cs- ~(137)Ba, ~(125)Sb-~(125M)Te, ~(95)Zr-~(95)Nb, and Mn. In addition, fallout from two Chinese nudear tests was detected, and seven shorter-lived radionudides added by these tests were measured, induding the activation product ~(239)Hp.