Improving Our Knowledge on the 229mThorium Isomer: Toward a Test Bench for Time Variations of Fundamental Constants
Improving Our Knowledge on the 229mThorium Isomer: Toward a Test Bench for Time Variations of Fundamental Constants
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DOI：
10.1002/andp.201800381
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发表时间：
2019-02
影响因子：
2.4
通讯作者：
P. Thirolf;B. Seiferle;Lars der Wense
中科院分区：
文献类型：
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作者：
P. Thirolf;B. Seiferle;Lars der Wense
四十多年来，原子核中最低的激发态，即229 Th的低位异构态，即所谓的钍异构体，一直在挑战各个学科的物理学家。作为一种具有独特的低激发能<10 eV的单光子晶体，其预测寿命为几个小时，导致相对线宽ΔE/E低至10-20。虽然直到最近，它存在的迹象仅基于间接证据，但其独特的性质激发了许多潜在的应用，例如使用钍异构体作为核频率标准，甚至可能优于最好的原子钟，并提高了对基本常数潜在时间变化的敏感性。本文提出了利用229 mTh的独特性质的各种建议，特别关注其作为基本常数（如精细结构常数）随时间变化的测试台的能力。
For more than four decades, the lowest excitation in the whole landscape of atomic nuclei, the low‐lying, isomeric state of 229Th, the so‐called thorium isomer, has challenged physicists of various disciplines. Being a solitaire with its uniquely low excitation energy of <10 eV, its predicted lifetime of a few hours results in an extremely sharp relative linewidth ΔE/E as low as 10–20. While until recently the indication of its existence was based only on indirect evidence, its unique properties inspired a multitude of potential applications, like the use of the thorium isomer as a nuclear frequency standard, potentially able to outperform even the best atomic clocks and a sensitivity‐enhanced access to potential temporal variations of fundamental constants. The various proposals to exploit the unique properties of 229mTh are presented herein, in particular focusing on its ability to serve as a test bench for time variations of fundamental constants like the fine structure constant.