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

丰中子核的质量是可靠的天体物理模型计算所必需的，已被证明可以探测远离稳定性的核结构反常，并为核结构模型提供重要的约束和测试。在这里，我建议使用著名的飞行时间(TOF)方法，第一次测量硫到钴区域中31个富中子核的质量。在以前的实验中，飞行时间质量测量技术已经被证明是国家超导回旋实验室(NSCL)非常短寿命的核素质量测量的理想方法。结果表明，系统不确定度可以达到150keV(6keV/Q)量级，没有明显的系统趋势随中子过量的变化。这一新发展的方法应该广泛地应用于新的群众，充分科学地利用它。这项测量将解决许多科学问题，从理解中子星地壳过程和对X射线瞬变的天文观测，到远离稳定性的核结构变化，如新的壳层关闭。

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.