Determination of the half-life of the ground state of {sup 229}Th by using {sup 232}U and {sup 233}U decay series

Journal Article · Fri Jul 15 00:00:00 EDT 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.84.014316· OSTI ID:21596562

Kikunaga, H ^[1]; Suzuki, T; Nomura, M ^[2]; Mitsugashira, T ^[3]; Shinohara, A ^[1]

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1. Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
2. Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Meguro-ku, Tokyo 152-8550 (Japan)
3. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577 (Japan)

The half-life of the ground state of {sup 229}Th ({sup 229}Th{sup g}) has become an important factor in nuclear technology, for example, in the geological disposal of nuclear spent fuel. However, the values reported in two previous studies are not in agreement. This study reevaluates the half-life of {sup 229}Th{sup g} by using a simple and reliable method. The {sup 232}U/{sup 233}U activity ratio of a {sup 232,233}U sample was measured by high-resolution {alpha}-particle spectrometry. Next, the {sup 228}Th/{sup 229}Th{sup g} activity ratio of the Th sample, which was grown from the {sup 232,233}U sample, was also measured. The half-life of {sup 229}Th{sup g} was calculated from these activity ratios, the growth time, and the half-lives of {sup 232}U, {sup 233}U, and {sup 228}Th. From the results of these five measurements, the half-life of {sup 229}Th{sup g} is determined to be 7932 {+-} 55 yr at a confidence level of 2{sigma}.

• OSTI ID: 21596562
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 84, Issue 1; Other Information: DOI: 10.1103/PhysRevC.84.014316; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
GROUND STATES
GROWTH
HALF-LIFE
NUCLEAR DECAY
RESOLUTION
SPECTROSCOPY
SPENT FUELS
THORIUM 228
THORIUM 229
URANIUM 232
URANIUM 233
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
DECAY
ENERGY LEVELS
ENERGY SOURCES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FUELS
HEAVY ION DECAY RADIOISOTOPES
HEAVY NUCLEI
ISOTOPES
MATERIALS
NEON 24 DECAY RADIOISOTOPES
NUCLEAR FUELS
NUCLEI
RADIOISOTOPES
REACTOR MATERIALS
SPONTANEOUS FISSION RADIOISOTOPES
THORIUM ISOTOPES
URANIUM ISOTOPES
YEARS LIVING RADIOISOTOPES