在反射不对称区域边界处的Laser光谱学
Laser spectroscopy of francium isotopes at the borders of the region of reflection asymmetry
摘要：
利用欧洲核子研究中心（CERN）ISOLDE新安装的共线共振电离光谱（CRIS）束线测量了富中子$^{218m,219,229,231}\text{Fr}$同位素的磁偶极矩和均方电荷半径的变化，探测了$7s~^{2}S_{1/2}$到$8p~^{2}P_{3/2}$的原子跃迁。$^{218m,219}\text{Fr}$和$^{229,231}\text{Fr}$的$δ\langle r^{2}\rangle^{A,221}$值遵循观察到的超过$N~=~126$的电荷半径的增加斜率。讨论了该丰中子区的电荷半径奇偶错列，表明$^{220}\text{Fr}$有弱的反奇偶错列，而$^{228}\text{Fr}$有正常的错列.这表明这两种同位素都位于一个反向交错区域的边界，这与反射不对称的形状有关。$g(^{219}\text{Fr}) = +0.69(1)$值支持基态的$π1h_{9/2}$壳模型配置。$g(^{229,231}\text{Fr})$值支持试探性的$I^π(^{229,231}\text{Fr}) = (1/2^{+})$自旋，并指向$πs_{1/2}^{-1}$入侵者基态配置。
英文摘要：
The magnetic dipole moments and changes in mean-square charge radii of the neutron-rich $^{218m,219,229,231}\text{Fr}$ isotopes were measured with the newly-installed Collinear Resonance Ionization Spectroscopy (CRIS) beam line at ISOLDE, CERN, probing the $7s~^{2}S_{1/2}$ to $8p~^{2}P_{3/2}$ atomic transition. The $δ\langle r^{2}\rangle^{A,221}$ values for $^{218m,219}\text{Fr}$ and $^{229,231}\text{Fr}$ follow the observed increasing slope of the charge radii beyond $N~=~126$. The charge radii odd-even staggering in this neutron-rich region is discussed, showing that $^{220}\text{Fr}$ has a weakly inverted odd-even staggering while $^{228}\text{Fr}$ has normal staggering. This suggests that both isotopes reside at the borders of a region of inverted staggering, which has been associated with reflection-asymmetric shapes. The $g(^{219}\text{Fr}) = +0.69(1)$ value supports a $π1h_{9/2}$ shell model configuration for the ground state. The $g(^{229,231}\text{Fr})$ values support the tentative $I^π(^{229,231}\text{Fr}) = (1/2^{+})$ spin, and point to a $πs_{1/2}^{-1}$ intruder ground state configuration.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
