Nuclear Structure and Nuclear Astrophysics

核结构与核天体物理学

• 批准号: 0457120
• 负责人: Michael Wiescher
• 金额: --
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0457120&HistoricalAwards=false
• 关键词: Nuclear; Structure; Astrophysics

Nuclear Astrophysics is, basically, the physics of stars. How the stars form, how they generate the energy that powers them, and how they reach their end--sometimes quietly, at other times in cataclysmic explosions--are the questions this field seeks to understand and provide answers to. The primary aim of the proposed work is to attempt to understand the nuclear reactions that are critical to the energy generation in stars and to the formation of most of the heavy elements that are observed in the Universe. We will use the particle accelerators available in our laboratory, and at laboratories around the world, to investigate specific nuclear reactions that are critical to our understanding of these phenomena, in particular the process of synthesis of heavy elements in the stellar environment. In a holistic approach, we will look at the rate at which certain reactions proceed and the impact these rates have on the generation of higher mass nuclei, measure the atomic masses of the nuclei that are crucial to this process, investigate the theoretical underpinnings of these reactions, and identify avenues of further research. We will also study bulk properties of nuclear matter to better understand the formation of neutron stars and the probability of supernova explosions in the final moments of a star's existence. In a novel approach to these investigations, we will use the techniques of accelerator mass spectrometry (widely known for its use in radiocarbon dating) to identify very rare processes occurring in astrophysical reactions. Another aspect of this work is to investigate some exotic aspects of the quantal motion of the atomic nuclei. The primary aim of these investigations of the "structure" of the atomic nuclei is to understand the fundamental way in which the constituents of the atomic nucleus--the protons and neutrons--interact with each other, and how these interactions lead to the observed nuclear properties. A number of the proposed studies of nuclear structure have direct implications on the astrophysical phenomena the investigation of which constitute the main body of this project. A very important component of the proposed work is training of young scientists. A large number of graduate students and undergraduate students will be involved with this work, in addition to a few postdoctoral fellows. These young cientists will, in the future years, form the pool of highly-trained personnel, so crucial not only to the continuing leadership of the United States in frontier fields of science and technology, but also to our efforts in defense and homeland security.

核天体物理学基本上是恒星物理学。恒星如何形成，它们如何产生为其提供动力的能量，以及它们如何到达终点——有时悄无声息，有时发生灾难性的爆炸——是这个领域寻求理解和提供答案的问题。这项工作的主要目的是试图了解核反应，这些反应对于恒星能量的产生以及宇宙中观察到的大多数重元素的形成至关重要。我们将使用我们实验室和世界各地实验室提供的粒子加速器来研究对我们理解这些现象至关重要的特定核反应，特别是恒星环境中重元素的合成过程。在整体方法中，我们将研究某些反应进行的速率以及这些速率对产生更高质量原子核的影响，测量对该过程至关重要的原子核的原子质量，研究这些反应的理论基础，并确定进一步研究的途径。我们还将研究核物质的整体特性，以更好地了解中子星的形成以及恒星存在的最后时刻超新星爆炸的可能性。在这些研究的新颖方法中，我们将使用加速器质谱技术（因其在放射性碳测年中的应用而广为人知）来识别天体物理反应中发生的非常罕见的过程。这项工作的另一个方面是研究原子核量子运动的一些奇异方面。这些对原子核“结构”研究的主要目的是了解原子核的组成部分（质子和中子）彼此相互作用的基本方式，以及这些相互作用如何导致观察到的核性质。一些拟议的核结构研究对天体物理现象有直接影响，天体物理现象的研究构成了该项目的主体。拟议工作的一个非常重要的组成部分是对年轻科学家的培训。除了一些博士后之外，大量的研究生和本科生将参与这项工作。这些年轻科学家将在未来几年形成训练有素的人才库，这不仅对美国在前沿科学技术领域的持续领导地位至关重要，而且对我们在国防和国土安全方面的努力也至关重要。