CHAPTER 4 CONCLUSIONS AND RECOMMENDATIONS 4.1 CONCLUSIONS For peak o-erpressures greater than about 1 pai, there is a highly satisfactory degree of eea consistency between the overp’ essures measured at sea level and the parachute-gauge meas- urements when the latter are corrected for varying ambient atmospheric conditions according to the Fuchs scaling law. Peck overpreasures of leas than 1 psi were reached at such groat distancss (>49,000 ft for King, and >100,000 ft for Mike) that it was to be expected that refraction effects would reduce the overpressures at sea level relative to those at high altitudes, and this is in accosdance with the observations. Uf it is assumed that the ground-reflection factor of 1.77 found by comparing the Mach and free-air peak overpressures in King shot is also applicable to Mike shot, the peak overpressures of Mike ahot should be equai to those of a bomb of yield 11 x 1.77 = 19.5 Mt in free air. Actually, as noted in Fig. 3.7, the Tumbler-Snapper free-air curve scaled up to an effective yield of 24 Mt more nearly represents the observed data. On this bas!s Mike shot appears to have had a blast efficiency of 2419.5 = 1.23 relative to the average of the Tumbier-Suapper ehots. Similarly, the present data indicate for King shot a blast efficiency relative to TumblerSnapper of 790/550 = 2.44. These figures are regarded as tentative and should not be accepted as indicative of a systematic departure from W" scaling in the directionof increased effective blast yield at very large energies until further comparison with data from other nuclear ex- plosions has been made. 4.2 RECOMMENDATIONS Thermal Detectao 3. Should attempts again be made to measure the thermal energy by devices on parachuted canisters, consideration should be given to a modification which would provide a transparent envelupe for the hot junction. Such a device, which could not be oblained in time for Ivy, is shown in Fig. 4.1 In both assembled and exploded views. Thermocouples of this type are under construction and will be tested for response under both quiet and windy conditions, for optical efficiency as omnidirectional detectors, for freedom from susceptibility to shock, etc.; that is, for all such requircments as m’ y suggest themselves. 38 STieiromineae eae ane re Tbscuoi so RESTRICTED DATA QM SECURITY INFORMATION