Probing Exotic Nuclear Masses and Structure Relevant to the Heavy Element Nucleosynthesis

理解原子核的结构对于理解这些核是如何产生的很重要。 由于近70%的比铁重的原子核和所有的锕系元素都是由所谓的r-过程产生的，而这种过程被认为是非常剧烈的环境，能够产生极其奇异的原子核，因此不仅要了解自然界中的稳定原子核，还要了解极端恒星事件中产生的非常奇异的原子核。 目前的稀有同位素束设施正在朝着生产其中一些核的方向取得进展。 该项目目前的目标是了解非常奇特的原子核的最基本性质-它们的质量。 通过了解核质量和质量趋势，可以了解在奇异环境中的核如何与其他核相互作用，以及核丰度如何在这些环境中变化。接近r过程路径的核质量将用飞行时间（TOF）技术测量。 在这种技术中，将在碎片分离器中的两个点之间测量混合核束的飞行时间。 将未知原子核的飞行时间与已知原子核的飞行时间进行比较将有助于确定未知原子核的质量。 物理和化学研究所的放射性离子束工厂和国家超导回旋加速器实验室计划并批准了几项实验。 除了更好地理解科学中最基本的问题之一，这项实验还将为美国的科学和科学家提供一个未来。 科学家将接受包括博士在内的各级培训。和本科阶段以及高中和小学阶段。 直接培养博士学生将在多个高调的实验中发生。 此外，还将为本科生和高中生开展多种辅助外联活动，以激发学生对科学的兴趣。

Understanding the structure of atomic nuclei is important in understanding how those nuclei are produced. As nearly 70% of nuclei heavier than iron and all of the actinides were produced by the so-called r-process in what is presumed to be very violent environments capable of producing extremely exotic nuclei, it is important to understand not just the stable nuclei in nature, but the very exotic ones produced in extreme stellar events. Current rare isotope beam facilities are making progress towards producing some of these nuclei. The current aim of this project is to understand the most fundamental property of very exotic atomic nuclei - their mass. By understanding nuclear masses and mass trends, it is possible to understand how nuclei in exotic environments interact with others and how nuclear abundance changes in these environments.Nuclear masses approaching the r-process path will be measured with the Time of Flight (TOF) technique. In this technique, the flight time for a mixed beam of nuclei will be measured between two points in a fragment separator. Comparing the flight times of unknown nuclei to those of known nuclei will help determine the masses of the unknown nuclei. Several experiments are planned and approved at the Radioactive Ion Beam Factory at The Institute of Physical and Chemical Research and at the National Superconducting Cyclotron Laboratory. In addition to gaining a better understanding of one of the most fundamental questions in science, this experiment will work to provide a future for science and scientists in the United States. Scientists will be trained at all levels, including the Ph.D. and undergraduate level as well as at the high-school and elementary level. Direct training of Ph.D. students will occur in multiple high-profile experiments. Further, multiple auxiliary outreach activities to undergraduate and high-school students will be done in order to excite and inform students about science.