Nuclear Astrophysics With Heavy Ions

元素的起源仍然是当今科学中最重要的问题之一。与此密切相关的是恒星燃烧和致密核物质的特性问题。该奖项将直接解决这些问题。 具体来说，这两个PI和与他们一起工作的学生将探索重元素是如何在恒星环境中形成的，确定对致密核物质特性的限制，并测量远离稳定性的奇异核的裂变势垒。 收集的数据也将有助于解决理论计算之间的差异。 PI将为本科生和研究生提供广泛技能和技术的直接培训，这将为学生在STEM领域具有挑战性和重要的职业生涯做好准备。 主要问题是：（1）r过程是否包含N ~ 74处的核形共存区？测量r-过程路径附近的核质量对于理解r-过程演化的系统学是至关重要的，r-过程演化负责产生几乎所有比铁重的核。(2)当密度和不对称性接近中子星时，核状态方程的对称项是什么？这对于了解中子星的许多方面都起着至关重要的作用，例如它们的大小，惯性矩，冷却速率和内部地壳的厚度。(3)在r-过程路径的终点附近，核的裂变几率是多少？这个问题对于理解天体物理r过程的终止和限制其中的任何裂变循环至关重要。 探索这些问题的实验已经在国家超导回旋加速器实验室获得批准。

The origin of the elements remains one of the most important questions in science today. Closely tied to this are questions of stellar burning and the characteristics of dense nuclear matter. This award will address these questions directly. Specifically, the two PIs and the students working with them will explore how heavy elements were formed in stellar environments, determine constraints on the characteristics of dense nuclear matter, and measure the fission barriers of exotic nuclei far from stability. The data collected will also help to resolve the discrepancies between theoretical calculations. The PIs will provide direct training to both undergraduate and graduate students in a wide range of skills and techniques, which will prepare the students for challenging and important careers in STEM fields. The central questions addressed by the proposed work are: (1) Does the r-process include a region of nuclear shape co-existence at N ~ 74? Measurement of nuclear masses near the r-process path is vital in understanding the systematics of r-process evolution, which is responsible for the production of nearly all nuclei heavier than iron. (2) What is the symmetry term of the nuclear equation-of-state at densities and asymmetries approaching those of neutron stars? This plays a vital role in the understanding of many aspects of neutron stars, such as their sizes, moments of inertia, cooling rates, and the thickness of their inner crusts. (3) What are the fission probabilities of nuclei near the termination of the r-process path? This question is critical in understanding the termination of the astrophysical r-process and constraining any fission cycling therein. Experiments to explore these questions have already been approved at the National Superconducting Cyclotron Laboratory.