YIELD OF THE HIROSHIMA WEAPON,

The airborne microphone gage pressure record of the Hiroshima shot is used to determine the yield of the Little Boy weapon. The geometry of the Hiroshima mission is reconstructed and analyzed to determine the slant range between the burst point and the canister along which the shock traveled. The height of burst, slant range and peak pressure are used in the Naval Ordnance Laboratory-Nonhomogeneous Atmospheric Transmission code to determine the energy yield of the Hiroshima weapon. The result of this analysis is a plot of weapon yield as a function of slant range for the peak pressure observed at Hiroshima. The yield of the Hiroshima weapon, based on the slant range determination in this report, is 15.2 kt. This result should be of interest to those concerned with physical vulnerability analyses based on Hiroshima data. Some discussion is given on other methods of finding the yield of the Hiroshima weapon. Author