Time-of-flight mass measurements of neutron-rich nuclei

富中子核的质量是可靠的天体物理模型计算所必需的，并且已被证明可以探测远离稳定的核结构异常，并为核结构模型提供重要的约束和测试。我在此建议首次使用成熟的飞行时间（TOF）方法测量硫钴区31个中子丰富核的质量。在国家超导回旋加速器实验室（NSCL）之前的实验中，TOF技术已经被证明是非常适合于短寿命核素质量测量的一种理想方法。结果表明，系统不确定度可以达到150 keV （6keV/q）量级，随中子过剩量的变化没有明显的系统趋势。要把这种新发展起来的方法应用到更广泛的新群众中去，充分科学地加以利用。这次测量将解决许多科学问题，从了解中子星地壳过程和x射线瞬态的天文观测到远离稳定的核结构变化，如新的壳闭合。

The masses of neutron-rich nuclei are needed for reliable astrophysical model calculations and have been shown to probe nuclear structure anomalies far from stability and to provide important constraints and tests for nuclear structure models. I propose here to measure the masses of 31 neutron-rich nuclei in the sulfur to cobalt region for the first time, using the well-established time-of-flight (TOF) method. The TOF technique for mass measurements has been proven to be an ideally suited method for mass measurements on very short-lived nuclides at the National Superconducting Cyclotron Laboratory (NSCL) in previous experiments. The results demonstrate that systematic uncertainties of the order of 150 keV (6keV/q) can be achieved with no obvious systematic trends as functions of neutron excess. This newly developed method shall be applied to a broad range of new masses to fully exploit it scientifically. There are a number of scientific questions this measurement will address, ranging from understanding neutron star crust processes and astronomical observations of X-ray transients to changes of nuclear structure far from stability such as new shell closures.