Observations on the particle properties of nuclear debris in the upper atmosphere

Abstract

By means of an autoradiographic method, the number concentration of nuclear debris particles of different radioactivity content has been studied. The material consisted of air-filter samples taken at an altitude of 8–12 km in 1961–1963. In the periods studied the concentration of particles with diameters larger than about 0.5 μm was of the order 10–100 kg−1 in the lower stratosphere and decreased slowly with time. It was found that the content of such particles relative to the total radioactivity decreases fairly rapidly. It was also observed that the relative concentration of larger particles is higher in the tropospheric samples than in the stratospheric.DOI: 10.1111/j.2153-3490.1966.tb00258.x