TY - JOUR
T1 - Half-life estimation of the first excited state of Th229 by using α-particle spectrometry
AU - Kikunaga, H.
AU - Kasamatsu, Y.
AU - Haba, H.
AU - Mitsugashira, T.
AU - Hara, M.
AU - Takamiya, K.
AU - Ohtsuki, T.
AU - Yokoyama, A.
AU - Nakanishi, T.
AU - Shinohara, A.
PY - 2009/9/21
Y1 - 2009/9/21
N2 - To search for a direct-decay signal from the isomer Th229m, α-particle spectra of Th229m,g produced from 93 mg of U233 have been measured by using a rapid and high-resolution α-particle spectrometry, which can distinguish α lines of Th229m from those of its ground state. Although α events were not obtained in the expected energy region for Th229m with the exception of those derived from Th229g, we can estimate that the half-life of Th229m is shorter than 2 h at 3σ confidence level under the chemical condition of chloride or hydroxide.
AB - To search for a direct-decay signal from the isomer Th229m, α-particle spectra of Th229m,g produced from 93 mg of U233 have been measured by using a rapid and high-resolution α-particle spectrometry, which can distinguish α lines of Th229m from those of its ground state. Although α events were not obtained in the expected energy region for Th229m with the exception of those derived from Th229g, we can estimate that the half-life of Th229m is shorter than 2 h at 3σ confidence level under the chemical condition of chloride or hydroxide.
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U2 - 10.1103/PhysRevC.80.034315
DO - 10.1103/PhysRevC.80.034315
M3 - Article
AN - SCOPUS:70349845732
VL - 80
JO - Physical Review C - Nuclear Physics
JF - Physical Review C - Nuclear Physics
SN - 0556-2813
IS - 3
M1 - 034315
ER -