First Direct Mass Measurements of Nuclides around Z=100 with a Multireflection Time-of-Flight Mass Spectrograph
First Direct Mass Measurements of Nuclides around Z=100 with a Multireflection Time-of-Flight Mass Spectrograph
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DOI：
10.1103/physrevlett.120.152501
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发表时间：
2018-04-10
影响因子：
8.6
通讯作者：
Yamaki, S.
中科院分区：
文献类型：
--
作者：
Ito, Y.;Schury, P.;Yamaki, S.
用多反射飞行时间质谱仪直接测量了形变N=152中子壳附近由冷热聚变反应产生的Es-246、Fm-251以及转移核MD249-252和No-254的质量。首次测定了ES-246和MD-249、MD-250、MD-252的质量。用MD-249、MD-250的质量作为衰变链的锚点，测定了~(261)Bh和~(266)Mt的较重核质量。将这些新质量与理论全球质量模型进行了比较，结果表明它们与该地区的宏观-微观模型符合得很好。由三个同位素质量得到的经验壳层间隙参数(2n)用新的质量进行了更新，证实了Md和Lr存在形变的N=152中子壳闭合。
The masses of Es-246, Fm-251, and the transfermium nuclei Md249-252 and No-254, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N = 152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of Es-246 and Md-249,Md-250,Md-252 were measured for the first time. Using the masses of Md-249,Md-250 as anchor points for a decay chains, the masses of heavier nuclei, up to (261)Bh and (266)Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter delta(2n) derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N = 152 neutron shell closure for Md and Lr.