A Shorter 146Sm Half-Life Measured and Implications for 146Sm-142Nd Chronology in the Solar System (Retracted article. See vol. 379, 2023)
A Shorter 146Sm Half-Life Measured and Implications for 146Sm-142Nd Chronology in the Solar System (Retracted article. See vol. 379, 2023)
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DOI：
10.1126/science.1215510
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发表时间：
2012-03-30
期刊：
影响因子：
56.9
通讯作者：
Yokoyama, A.
中科院分区：
文献类型：
--
作者：
Kinoshita, N.;Paul, M.;Yokoyama, A.
已灭绝的p-过程核素Sm-146通过测量其α衰变子体Nd-142的同位素异常而作为天体物理和地球化学计时器。根据对Sm-146/Sm-147 α-活性和原子比的分析，我们确定Sm-146的半衰期为68 +/- 7（1 sigma）百万年，比目前使用的1.03 +/- 5百万年的值短。这个半衰期值意味着早期太阳系中Sm-146的初始丰度比先前估计的要高，（Sm-146/Sm-144）（0）= 0.0094 +/- 0.0005（2 sigma）。由于新的Sm-146半衰期和（Sm-146/Sm-144）（0）值的综合作用，用Sm-146-Nd-142定年的地球、月球和火星行星硅酸盐地幔分异事件收敛到一个较短的时间跨度，而且一般收敛到较早的时间。
The extinct p-process nuclide Sm-146 serves as an astrophysical and geochemical chronometer through measurements of isotopic anomalies of its alpha-decay daughter Nd-142. Based on analyses of Sm-146/Sm-147 alpha-activity and atom ratios, we determined the half-life of Sm-146 to be 68 +/- 7 (1 sigma) million years, which is shorter than the currently used value of 103 +/- 5 million years. This half-life value implies a higher initial Sm-146 abundance in the early solar system, (Sm-146/Sm-144)(0) = 0.0094 +/- 0.0005 (2 sigma), than previously estimated. Terrestrial, lunar, and martian planetary silicate mantle differentiation events dated with Sm-146-Nd-142 converge to a shorter time span and in general to earlier times, due to the combined effect of the new Sm-146 half-life and (Sm-146/Sm-144)(0) values.