Meteorological observations at Hiroshima on days with weather similar to that of the atomic bombing.
An attempt to explain discrepancies between measured neutron-induced radioactivities (i.e., 152Eu, 60Co) and calculated yields based on the Dosimetry System 1986 was made by considering moist air densities at different altitudes over Hiroshima, Japan. The investigation checked the validity of moist air density estimates used in the Dosimetry System 1986 computer codes. Meteorological observations were conducted to obtain atmospheric temperature and pressure profiles for the Hiroshima area. By coupling these observations with surface measurements taken on 6 August 1945 at Ebayama Park (3.6 km from the hypocenter), estimates of temperature, pressure, and humidity at the time of detonation were derived. This allowed the calculation of densities for dry air, moist air, and water vapor. The results proved similar to the Dosimetry System 1986 estimates. Water vapor density calculations showed the largest difference (at most 7%). These results imply that the 152Eu yield contradiction in the Dosimetry System 1986 calculations vs. real measurements for large ground distances (> 900 m) is not the result of an erroneous estimate of moist air density in Hiroshima.
Hoshi
M
M
Research Institute for Nuclear Medicine and Biology, Hiroshima University, Japan.
Sawada
S
S
Nagatomo
T
T
Neyama
Y
Y
Marumoto
K
K
Kanemaru
T
T
D003037:Cobalt Radioisotopes; D005063:Europium; D006801:Humans; D007564:Japan; D008685:Meteorological Concepts; D009502:Neutrons; D009689:Nuclear Warfare; D011829:Radiation Dosage; D011847:Radioactive Fallout; D011868:Radioisotopes; D014887:Weather
D003037:Cobalt Radioisotopes; D011847:Radioactive Fallout; D011868:Radioisotopes; D005063:Europium