Quantum Science and Technology (NIST)

Graduate School of Science, The University of Tokyo

Summary of Presentations

A research team consisting of Dr. Takehito Hayakawa and Dr. Toshiyuki Shizuma at National Institutes for Quantum Science and Technology (Dr. Shigeo Koyasu, President) and Prof. Tsuyoshi Iizuka, at Graduate School of Science, the University of Tokyo, has used a new experimental method to measure the most accurate half-life of the long-lived radioactive isotope lutecium-176 (¹⁷⁶Lu), one of the nuclear cosmochronometer, and solved the problem that previously measured the half-lives differ significantly.

By measuring the amounts of lutecium-176 and hafnium-176 in a sample such as a meteorite, it is possible to determine the age of the formation of the meteorite or asteroid being the parent body of the meteorite (Figure).

​In the future, it is expected that the presently obtained half-life will be used to investigate the formation ages of various celestial bodies in the solar system and the formation age of the crusts of celestial bodies. It is also expected to measure the age of the supernova explosion that affected the formation of the solar system.

Figure: Conceptual diagram of the space clock. From the ratio of the amount of parent nuclei and daughter nuclei, the time since the parent nucleus was trapped in a meteorite (the time since the meteorite was formed) is measured.

The results of this research were published in Communications Physics on November 3.

For more information, please visit the website of the National Institute of Quantum Science and Technology (NIST) .

Journal

Journal name	Communications Physics
Title of paper	Half-life of the nuclear cosmochronometer 176Lu measured with a windowless 4π solid angle scintillation detector