论文标题
高精度质量测量的双重魔术$^{208} $ pb
High-precision mass measurement of doubly magic $^{208}$Pb
论文作者
论文摘要
The absolute atomic mass of $^{208}$Pb has been determined with a fractional uncertainty of $7\times 10^{-11}$ by measuring the cyclotron-frequency ratio $R$ of $^{208}$Pb$^{41+}$ to $^{132}$Xe$^{26+}$ with the high-precision Penning-trap mass光谱仪pentatrap和计算约束能量$ e _ {\ text {pb}} $和$ e _ {\ text {xe}} $分别带有41和26个原子电子，以及与初始相对性的多核电多核电派迪亚拉克 - 迪亚拉克 - 毛treeee-mcdhfhfhfhfhfhff） $ r $的相对精度为$ 9 \ times 10^{ - 12} $。 $E_{\text{Pb}}$ and $E_{\text{Xe}}$ have been computed with an uncertainty of 9.1 eV and 2.1 eV, respectively, yielding $207.976\,650\,571(14)$ u (u$=9.314\,941\,024\,2(28)\times $^{208} $ pb中性原子质量的10^{8} $ ev/c $^2 $）。该结果与2020年原子质量评估（AME）的1.2σ$达成一致，同时将精度提高了近两个数量级。新的质量值直接提高了Z = 81-84区域中14个核素的质量精度，并且是> 200的最精确质量值。因此，测量建立了一个可以使用的新的参考质量值区域，例如为了精确测定三硫核素的质量，包括超速。
The absolute atomic mass of $^{208}$Pb has been determined with a fractional uncertainty of $7\times 10^{-11}$ by measuring the cyclotron-frequency ratio $R$ of $^{208}$Pb$^{41+}$ to $^{132}$Xe$^{26+}$ with the high-precision Penning-trap mass spectrometer Pentatrap and computing the binding energies $E_{\text{Pb}}$ and $E_{\text{Xe}}$ of the missing 41 and 26 atomic electrons, respectively, with the ab initio fully relativistic multi-configuration Dirac-Hartree-Fock (MCDHF) method. $R$ has been measured with a relative precision of $9\times 10^{-12}$. $E_{\text{Pb}}$ and $E_{\text{Xe}}$ have been computed with an uncertainty of 9.1 eV and 2.1 eV, respectively, yielding $207.976\,650\,571(14)$ u (u$=9.314\,941\,024\,2(28)\times 10^{8}$ eV/c$^2$) for the $^{208}$Pb neutral atomic mass. This result agrees within $1.2σ$ with that from the Atomic-Mass Evaluation (AME) 2020, while improving the precision by almost two orders of magnitude. The new mass value directly improves the mass precision of 14 nuclides in the region of Z=81-84 and is the most precise mass value with A>200. Thus, the measurement establishes a new region of reference mass values which can be used e.g. for precision mass determination of transuranium nuclides, including the superheavies.
