AIR-BORNE RADIONUCLIDE MEASUREMENTS AND PHYSICAL CHARACTERISTICS DETERMINATION

ivewly developed counting techniques which ernploy multidimensional gamma-ray spectrometry have been employed for the d i r e c t measurement of a large group of radionuclides i n f a l l o u t samples.Tnis spectrometric countir& nethcd hzs made it possible t o study t h e d i s t r i b u t i o n of m n y of the t r a c e constituents of f a l l o u t and a l s o t o improve the precision f o r the measureiwnt of the longer 7 22 l i v e d f a l l o u t radionuclides.Tqe coccentrations of Be , N a , 124, %U5, cs134, cs137 95 __ l G 6 , AU 7 % i d 4 \ eo 60 , p, &95-, hi : d Ce 144 can be measured d i r e c t l y and t h e i r concentrations i n a i r &;ring t h e past 2-3/4 years m e reported.01' t h ?i'allout radionuclides i s reported, and t h e i r deposition The measured s o l u b i l i t y as dry f a l l o u t and as r a i n out i s cornpared i n t h e area of Richlacd i?!.ishington.The distribution and movement of the t r a c e r radior i u l i d e s $8, SbU4 both i n t h e stratosphere and troposphere as well as t h a t of l3-1~~' are discussed.rey produced radionuclides C138 and S38 i s mentioned and t h e i r application along with other cosmic-ray produced radionuclides i n 0.r discovery and t h e cosmicatmospheric research i s considered.