LIST OF FIGURES igure 1 Pege Comparison of Yield-Mass Curves for the Fission of U-235, U-238 and Pu-239, Fission Yields for the Fission of Pu-239 with Fast Neutrons . ° . e 7 2 Sketch of a Torus Cloud from a Device after Burst. . . . 17 3 Cloud Top and Bottom at Time of Stabilization for Various we 8 . . 19 Yield Weapons . . . 6 . 6 e 6 . 6 s . ee e e ew we The Atomic Cloud Model and the Forces Exerted Upon It 5 Time Required for Spherical Particles Having a 2.5 Density and a Certain Diameter to Fall from a Given Altitude to the Gr ound ° e o ° e e ° . ° e e e e « e 23 Dose Rate, Roentgens Per Hour Mixed Fission Products. . . 36 e 37 e ho « 2 H+l Hour Idealized Contour Lines for 20 KT Ground Burst, 15 8 Knot Wind oo e e ° e ° ° ° ° e e ® ° e Dosage Received With Various Times of Stay in Contaminated Area 9 eo e e o e e ° ° e eo e ° e e ° e e Wind Effects on Fall-out Pattern, with Superimposed Ideal- ized Contour . . . .« © «6 «© ©» © «© « «© «© «© 10 - Gross Gamma-Ray Decay of Fall-out Samples from CASTLE Shots , 1, 2, 3, and 4 “eo ° . e e ° e . ° e ° . ° ° ks li Percentage of Fall-out Expected from a Near Surface Burst Normalized to a Surface Burst . . . . . - «© « « AY 12 Lethality vs Dose in Roentgens . .- . - . . © «© 6 « 6H 13 A Graphic Representation of the Rere Equation for Times le we CB 14 Graphic Analysis of H+3 Hour Fall-out Situation with e e 69 . (t,) up to 19 Hours . Initial Dose Rate of ee ho Tt ee Per Hour ee e e ew e e lw ee 15 The MeCriteria Expressed in Terms of Dose Rate (r/hr) 16 Lethal Criteria Expressed in Terms of H+1 Hour Dose Rate at (t e Soke ee eee ee ee ee ee 72 for Various Times of Arrival of Fall-out or Entry into Contaminated Area Assuming Infinite Stay in Area . . . 7h 17. ‘Lethality Criteria Downwind (Along Contour Axis) As a . 2. 2. 2. 2 6 © © © © © © 6) FH 18 lethal Fall-out Areas . 2. . 2 6 1 6 6 © © 6 ew ew 66 19 Doses Accumulated up to 48 Hours After Burst Time for . . 78 Function of Yield Various Times of Entry into Contaminated Area v . .