Elwell R, Schneider Christian, Jeet Justin, Terhune J E S, Morgan H W T, Alexandrova A N, Tran Tan H B, Derevianko Andrei, Hudson Eric R
Department of Physics and Astronomy, <a href="https://ror.org/046rm7j60">University of California</a>, Los Angeles, California 90095, USA.
Department of Chemistry and Biochemistry, <a href="https://ror.org/046rm7j60">University of California</a>, Los Angeles, Los Angeles, California 90095, USA.
Phys Rev Lett. 2024 Jul 5;133(1):013201. doi: 10.1103/PhysRevLett.133.013201.
LiSrAlF_{6} crystals doped with ^{229}Th are used in a laser-based search for the nuclear isomeric transition. Two spectroscopic features near the nuclear transition energy are observed. The first is a broad excitation feature that produces redshifted fluorescence that decays with a timescale of a few seconds. The second is a narrow, laser-linewidth-limited spectral feature at 148.382 19(4){stat}(20){sys} nm [2020 407.3(5){stat}(30){sys} GHz] that decays with a lifetime of 568(13){stat}(20){sys} s. This feature is assigned to the excitation of the ^{229}Th nuclear isomeric state, whose energy is found to be 8.355 733(2){stat}(10){sys} eV in ^{229}Th:LiSrAlF_{6}.
掺杂有²²⁹Th的LiSrAlF₆晶体被用于基于激光的核同质异能跃迁搜索。在核跃迁能量附近观察到两个光谱特征。第一个是一个宽激发特征，它产生红移荧光，其衰减时间尺度为几秒。第二个是位于148.382 19(4)stat(20)sys nm [2020 407.3(5)stat(30)sys GHz]处的窄的、受激光线宽限制的光谱特征，其衰减寿命为568(13)stat(20)sys s。该特征被归因于²²⁹Th核同质异能态的激发，在²²⁹Th:LiSrAlF₆中其能量被发现为8.355 733(2)stat(10)sys eV。
