CiRyAR Ran a we 4 cp I"oH Ines I 11. The second method 1s to compare two shots, one clean and one conventional, of approximately the same total yield, and show that the fission yield of the clean one is many times less than the fission yield of the conventional one. In this method the fact that the total yields of the two shots are approximately the same can be determined without obtaining the absolute value of the total yield of either one. For example, using any of the hydrodynamic methods (fireball photography, time of shock arrival, or shock intensity) and placing the instrument station at a fixed put unknown distance from the zero point where both shots will be fired, it can easily be determined whether the total yields are comparable. le, The comparision of fission yields can be made by either of two methods. One is to determine for each shot the distributior of fission product activity within the stabilized cloud, This could be done by aircraft flying through the cloud with the proper instrumentation but the reliability and credibility are low Since the cloud development will differ on the two shots and the cloud penetrations cannot be duplicated, A better method is to measure the Lonization of the cloud by means of instrumented rockets which telemeter their readings to ground stations. About i@ rockets per shot launched at 5 to 7 minutes after detonation {at a time before wind shear sets in) would be sufficient to obtain good coverage of the distribution in the cloud and should Give reasonably accurate results. The ratio of these results would give the relative fission yields (Appendices "D" and "E"), 13. This second method does not have the credibility or in which total and fission yields This method also requires that yields of both devices be dependable. Z > me obe RS. vs are measured on a single clean shot. aN, reliability of the first method,

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