CROCKER, KAWAHARA, AND FREILING PAN | 325 170 | 80 e995 | T TTT 10! ] PErtyl 80 42 i 24 2 I 7 poy 8 ‘ Te e 107! PT Tt e or? 10! 10? 10 PARTICLE DIAMETER, p 104 Fig. 5—Effect of particle size on fractionation ratio. SUMMARY Correlations indicate that the fractionation behavior of ™Sr, *Sr, Sty '8%cs, 4°Ba, and Ce relative to Zr in silicate-surface bursts does not differ essentially from that observed in a coral-surface burst or in air bursts. Differences are noted for °°Mo and 7*Np. For !Ru, Ru, 1, Te,cs Moe, and 7% Pu, some differences in degree of fractionation are indicated, and further study of these nuclides is recommended. ACKNOWLEDGMENTS In addition to the U. S. Atomic Energy Commission, the Defense Atomic Support Agency contributed. generously to the support of this study. Some of the data were obtained from U. S. Air Force sources. REFERENCES 1, D. E, Clark, F. K. Kawahara, and W. C. Cobbin, Fallout Sampling and Analy- sis: Radiation Dose Rate and Dose History at 16 Locations, Report POR-