Residual 152Eu and 60Co activities induced by neutrons from the Hiroshima atomic bomb
- Hiroshima Univ. (Japan)
Specific activities of 152Eu:Eu in stone samples exposed to the Hiroshima atomic bomb were determined for 70 samples up to a 1,500-m slant range from the epicenter. The specific activities of 60Co:Co were also determined for six samples near the Hiroshima hypocenter. First, the 152Eu data were investigated to find out the directional dependence of neutron activation. Directional anisotropy was not definite; however, there was an indication that the activation in the west-southwest was lower than in other directions. Second, measured 152Eu and 60Co radioactivity data were compared with activation calculations based on DS86 neutrons. It is clearly shown that the measured data are lower than the calculation near the hypocenter and vice versa at long distances beyond 1,000 m. The calculated-to-measured ratios of 152Eu are 1.6 at the hypocenter, 1.0 at approximately 900 m, and 0.05 at a 1,500-m slant range. Present results indicate that systematic errors exist in the DS86 neutrons concerning the source-term spectrum, neutron transport calculations in air, and/or activation measurements.
- OSTI ID:
- 5673610
- Journal Information:
- Health Physics; (United States), Vol. 65:3; ISSN 0017-9078
- Country of Publication:
- United States
- Language:
- English
Similar Records
Activation Measurements for Thermal Neutrons, U.S. Measurements of 36Cl in Mineral Samples from Hiroshima and Nagasaki; and Measurement of 63 Ni in Copper Samples From Hiroshima by Accelerator Mass Spectrometry
Benchmark test of neutron transport calculations: Indium, nickel, gold, europium, and cobalt activation with and without energy moderated fission neutrons by iron simulating the Hiroshima atomic bomb casing
Related Subjects
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
COBALT 60
ACTIVITY LEVELS
SPATIAL DISTRIBUTION
EUROPIUM 152
LITTLE BOY
RADIATION EFFECTS
COMPARATIVE EVALUATIONS
HIROSHIMA
NEUTRON TRANSPORT
NUCLEAR EXPLOSIONS
RADIOACTIVITY
ASIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
COBALT ISOTOPES
DEVELOPED COUNTRIES
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
EUROPIUM ISOTOPES
EVALUATION
EXPLOSIONS
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
JAPAN
MINUTES LIVING RADIOISOTOPES
NEUTRAL-PARTICLE TRANSPORT
NUCLEAR WEAPONS
NUCLEI
ODD-ODD NUCLEI
RADIATION TRANSPORT
RADIOISOTOPES
RARE EARTH ISOTOPES
WEAPONS
YEARS LIVING RADIOISOT
540230* - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- (1990-)
450200 - Military Technology
Weaponry
& National Defense- Nuclear Explosions & Explosives