Laser spectroscopic characterization of the nuclear-clock isomer ^229mTh

authored by

Johannes Thielking, Maxim V. Okhapkin, Przemysław Głowacki, David M. Meier, Lars Von Der Wense, Benedict Seiferle, Christoph E. Düllmann, Peter G. Thirolf, Ekkehard Peik

Abstract

The isotope ²²⁹Th is the only nucleus known to possess an excited state ^229mTh in the energy range of a few electronvolts- A transition energy typical for electrons in the valence shell of atoms, but about four orders of magnitude lower than typical nuclear excitation energies. Of the many applications that have been proposed for this nuclear system, which is accessible by optical methods, the most promising is a highly precise nuclear clock that outperforms existing atomic timekeepers. Here we present the laser spectroscopic investigation of the hyperfine structure of the doubly charged ^229mTh ion and the determination of the fundamental nuclear properties of the isomer, namely, its magnetic dipole and electric quadrupole moments, as well as its nuclear charge radius. Following the recent direct detection of this long-sought isomer, we provide detailed insight into its nuclear structure and present a method for its non-destructive optical detection.

External Organisation(s)

National Metrology Institute of Germany (PTB)
Poznan University of Technology
Ludwig-Maximilians-Universität München (LMU)
GSI Helmholtz Centre for Heavy Ion Research
Helmholtz-Institut Mainz
Johannes Gutenberg University Mainz

Type

Article

Journal

NATURE

Volume

556

Pages

321-325

No. of pages

5

ISSN

0028-0836

Publication date

19.04.2018

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

General

Electronic version(s)

https://doi.org/10.1038/s41586-018-0011-8 (Access: Closed)