Colloquium: Laser probing of neutron-rich nuclei in light atoms
Colloquium: Laser probing of neutron-rich nuclei in light atoms
复制标题
DOI：
10.1103/revmodphys.85.1383
复制
发表时间：
2013-07
影响因子：
44.1
通讯作者：
Zheng‐Tian Lu;P. Mueller;G. Drake;W. Nörtershäuser;S. Pieper;Z.-C. Yan
中科院分区：
文献类型：
--
作者：
Zheng‐Tian Lu;P. Mueller;G. Drake;W. Nörtershäuser;S. Pieper;Z.-C. Yan
富含中子的He-6和He-8同位素显示出一种奇特的核结构，它由一个紧密结合的类He-4核心组成，附加的中子在相对较远的距离上绕轨道运行，形成一个晕圈。最近的实验工作已经成功地激光捕获和冷却这些短暂的稀有氦原子，并通过对被捕获的单个原子进行激光光谱分析，测量了沿He-4-He-6-He-8链的原子同位素位移。同时，包括相对论修正和QED修正在内的少电子原子结构理论在计算同位素位移方面已经达到了相当的精度。在平行的工作中，也通过测量原子同位素位移，研究了锂和铍同位素的核电荷半径。所使用的技术是中性的、热的锂原子的共振电离光谱和铍离子的共线激光光谱。结合原子理论和激光光谱学的进展，这些轻晕核的电荷半径现在首次被确定，而不依赖于核结构模型。结果与一些核结构计算的预测值进行了比较，并用于指导我们对极富中子环境中的核力的理解。
The neutron-rich He-6 and He-8 isotopes exhibit an exotic nuclear structure that consists of a tightly bound He-4-like core with additional neutrons orbiting at a relatively large distance, forming a halo. Recent experimental efforts have succeeded in laser trapping and cooling these short-lived, rare helium atoms and have measured the atomic isotope shifts along the He-4-He-6-He-8 chain by performing laser spectroscopy on individual trapped atoms. Meanwhile, the few-electron atomic structure theory, including relativistic and QED corrections, has reached a comparable degree of accuracy in the calculation of the isotope shifts. In parallel efforts, also by measuring atomic isotope shifts, the nuclear charge radii of lithium and beryllium isotopes have been studied. The techniques employed were resonance ionization spectroscopy on neutral, thermal lithium atoms and collinear laser spectroscopy on beryllium ions. Combining advances in both atomic theory and laser spectroscopy, the charge radii of these light halo nuclei have now been determined for the first time independent of nuclear structure models. The results are compared with the values predicted by a number of nuclear structure calculations and are used to guide our understanding of the nuclear forces in the extremely neutron-rich environment.