DATE2026.05.28 #Press Releases

Successful lifetime measurement of tellurium 104, the fastest alpha-decaying

Disclaimer: machine translated by DeepL which may contain errors.

Discovery of Formation of Extremely Strong Alpha Clusters in the Vicinity of the Double Magic Nucleus

Summary 

An international research group led by Senior Scientist Shunji Nishimura, General Manager Hiroki Sakurai, RI Beam Separation and Generator Team Engineer Naoki Fukuda, RIKEN Nishina Center for Accelerator-based Science, Researcher Shintaro Goh, Nuclear Structure Research Division, Assistant Professor Rin Yokoyama of the Center for Nuclear Study, Graduate School of Science, The University of Tokyo, Assistant Professor Noritaka Kitamura of the Graduate School of Science, The University of Tokyo, and Research Fellow Ian Cox of the University of Tennessee, Professor Robert Grzywacz, and Research Scientist Tobias King of Oak Ridge National Institute have succeeded in directly measuring the alpha (α) decay of tellurium-104 ( ¹⁰⁴Te ), a very short-lived radioisotope (RI), for the first time, and found that its half-life is approximately 7.2 nanoseconds (1 The half-life of 104Te is approximately 7.2 nanoseconds (1 nanosecond is one billionth of a second). This is the fastest α-decay from the ground state known to date.

This achievement deepens our understanding of the formation of α-cluster structures in nuclei and also leads to the elucidation of nuclear structures in the vicinity of magic numbers.

In α-decay, an α-particle (helium nucleus) consisting of two protons and two neutrons is formed inside a nucleus and is ejected out of the nucleus due to the quantum tunneling effect and other factors. Based on the measured decay probabilities, the international research group derived the α-particle formation probability, which indicates the degree to which α-particles are formed inside the nucleus. As a result, it was found that the α-particle formation probability of ¹⁰⁴Te is the highest among all known α-decay nuclei, and is about twice that of known nuclei. This high α-particle formation probability is thought to be closely related to the unique structure of ¹⁰⁴Te that decays to a doubly magic nucleus, ¹⁰⁰ tin ( ¹⁰⁰Sn ).

This study will be published in the scientific journal Nature on May 27 (May 28 Japan time).

The process from ¹²⁴Xe through ¹⁰⁸Xe and ¹⁰⁴Te to the double magic nucleus ¹⁰⁰Sn

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