Bilous Pavlo V, Bekker Hendrik, Berengut Julian C, Seiferle Benedict, von der Wense Lars, Thirolf Peter G, Pfeifer Thomas, López-Urrutia José R Crespo, Pálffy Adriana
Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany.
Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027-5255, USA.
Phys Rev Lett. 2020 May 15;124(19):192502. doi: 10.1103/PhysRevLett.124.192502.
The excitation of the 8 eV ^{229m}Th isomer through the electronic bridge mechanism in highly charged ions is investigated theoretically. By exploiting the rich level scheme of open 4f orbitals and the robustness of highly charged ions against photoionization, a pulsed high-intensity optical laser can be used to efficiently drive the nuclear transition by coupling it to the electronic shell. We show how to implement a promising electronic bridge scheme in an electron beam ion trap starting from a metastable electronic state. This setup would avoid the need for a tunable vacuum ultraviolet laser. Based on our theoretical predictions, determining the isomer energy with an uncertainty of 10^{-5} eV could be achieved in one day of measurement time using realistic laser parameters.
理论上研究了高电荷离子中通过电子桥机制对8电子伏特^{229m}钍异构体的激发。通过利用开放4f轨道丰富的能级结构以及高电荷离子对光电离的鲁棒性，脉冲高强度光学激光可通过将其与电子壳层耦合来有效驱动核跃迁。我们展示了如何从亚稳电子态出发在电子束离子阱中实现一种有前景的电子桥方案。这种装置将无需可调谐真空紫外激光。基于我们的理论预测，使用实际的激光参数，在一天的测量时间内就可以实现将异构体能量测定到10^{-5}电子伏特的不确定度。
