New Tools for Radiative Neutron Capture in Stars and on Earth

在恒星和地球上捕获辐射中子的新工具

• 批准号: 1415656
• 负责人: Carlos Bertulani
• 金额: $ 35万
• 依托单位: Texas A&M University-Commerce
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1415656&HistoricalAwards=false
• 关键词: New; Tools; Radiative; Neutron; Capture

Neutron capture in stars leading to the formation of heavy elements, as well as nucleon induced fission, are at the forefront of nuclear physics research. Because the neutron lacks charge, reactions with free neutrons are very difficult, and popular tools such as deuteron stripping (d,p) reactions are often used instead. The neutron inside the deuteron is bound and its energy, momentum, and angular momentum do not directly relate to the same quantities for a free neutron. Hence, the development of advanced (d,p) theory is critical for the success of many experimental programs at existing and future radioactive beam facilities. The overarching objective of this project is to advance the theory of deuteron stripping reactions leading to bound states and resonances, providing reliable connections between (d,p) reaction cross sections and the corresponding (direct or resonant) neutron capture cross sections on unstable nuclei. In this project the investigators will develop publicly available computer codes that will aid in the interpretation of low-energy experiments at radioactive beam facilities.Simple transfer reactions such as deuteron stripping (d,p) reactions carry many of the basic features of rearrangement reactions induced by heavier nuclei. They provide a unique tool for extracting nuclear information for neutron capture identified as one of the crucial inputs needed for nuclear astrophysics and applied physics studies, such as in advanced fuel cycles, nuclear energy and nuclear safety applications, and nuclear stockpile stewardship. Advanced reaction theory is the key to connecting (d,p) cross sections to neutron capture cross sections. This project is devoted to advancing low-energy reaction theory. The investigators will focus on obtaining accurate solutions of the generalized three-body Faddeev integral equations including explicitly the Coulomb interaction between nuclei. This project will provide training opportunities for students, who will have the chance to work on cutting-edge theoretical and computational developments of great importance for the future of nuclear physics.

恒星中的中子捕获导致重元素的形成，以及核子诱发的裂变，是核物理研究的前沿。由于中子缺乏电荷，与自由中子的反应非常困难，而常用的工具，如氘核剥离（d，p）反应。氘核内部的中子是被束缚的，它的能量、动量和角动量与自由中子的能量、动量和角动量没有直接关系。因此，先进的（d，p）理论的发展是成功的许多实验计划在现有和未来的放射性束设施的关键。该项目的首要目标是推进导致束缚态和共振的氘核剥离反应理论，提供（d，p）反应截面与不稳定核上相应的（直接或共振）中子俘获截面之间的可靠联系。在这个项目中，研究人员将开发公开可用的计算机代码，这将有助于解释在放射性束设施上进行的低能实验。简单的转移反应，如氘核剥离（d，p）反应，具有重核诱导的重排反应的许多基本特征。它们提供了一种独特的工具，用于提取中子捕获所需的核信息，中子捕获被确定为核天体物理学和应用物理学研究所需的关键投入之一，例如在先进燃料循环、核能和核安全应用以及核库存管理方面。先进的反应理论是连接（d，p）截面和中子俘获截面的关键。该项目致力于推进低能反应理论。研究人员将专注于获得广义三体Faddeev积分方程的精确解，其中明确包括核之间的库仑相互作用。该项目将为学生提供培训机会，他们将有机会从事对核物理未来非常重要的前沿理论和计算发展。