A Laser Excitation Scheme for Th-229m

作者：von der Wense Lars^*; Seiferle Benedict; Stellmer Simon; Weitenberg Johannes; Kazakov Georgy; Palffy Adriana; Thirolf Peter G

来源：Physical Review Letters, 2017, 119(13): 132503.

DOI：10.1103/PhysRevLett.119.132503

Direct laser excitation of the lowest known nuclear excited state in Th-229 has been a long-standing objective. It is generally assumed that reaching this goal would require a considerably reduced uncertainty of the isomer's excitation energy compared to the presently adopted value of (7.8 +/- 0.5) eV. Here we present a direct laser excitation scheme for Th-229m, which circumvents this requirement. The proposed excitation scheme makes use of already existing laser technology and therefore paves the way for nuclear laser spectroscopy. In this concept, the recently experimentally observed internal-conversion decay channel of the isomeric state is used for probing the isomeric population. A signal-to-background ratio of better than 10(4) and a total measurement time of less than three days for laser scanning appear to be achievable.

• 出版日期2017-9-28