The half-life of antimony-125

Radioactive antimony isotopes in the atmosphere

“…A rapid change in the Sb•'/ SF ø ratio appeared between 45,000 and 55,000 ft, and this gradient seems to have remained fairly constant over the summer of 1963 (only a small 'leveling out' is apparent in Figure 1). The radical change in the composition of the debris between January and April is in agreement with the concept that a period of vertical instability occurs in the polar stratosphere in winter and early spring, causing the well-known spring peaks in fallout rates [Kuroda et al, 1960[Kuroda et al, , 1962Lockhart et al, 1960] whereas the same regions of the stratosphere show a much higher stability in summer. Whether the downward movement of air takes place by eddy diffusion [Newell, 1963;Holland, 1963a] or by sinking of a cold air mass [Dobson, 1956] Values for tropical (~10øN) and middle (~30øN) latitudes are estimated from gross 7 ray spectrums.…”