US-Belgium Cooperative Science: Nuclear Astrophysics with Radioactive and Isomeric Beams and Targets

该奖项将支持美国和比利时两组物理学家在核天体物理学方面的联合研究。这个美国小组将在乔治城大学的威廉·S·罗德尼博士的指导下进行。比利时的合作者是比利时卢万核物理研究所的J.Vervier博士。该项目的目标是利用放射性束流进行一系列实验，以测量对理解核合成非常重要的截面。在新星、超新星、X射线爆发以及可能的早期宇宙中，温度和密度使得一些放射性核素(和同分异能核素)的寿命与质子或阿尔法粒子引发的核反应摧毁它们的燃烧时间相当。在这些情况下，在发展恒星演化和核合成的模型时必须考虑这些反应。因此，使用放射性靶标和/或射束的可能性正受到核物理界越来越多的关注。在这个项目中，概述的一系列实验代表着朝着提供所需横截面信息的方向迈出了重要的一步。卢万-拉-诺夫耦合回旋加速器装置将能够产生进行这些实验所需的束流强度。美国目前还没有能够进行这种辐射束测量的设施。这项研究将受益于罗德尼博士在核天体物理学方面的专业知识，以及他的研究小组在活跃的核实验方面的背景。这项研究的结果将有助于我们理解恒星的演化和恒星中的核合成。

This award will support joint research in nuclear astrophy- sics between two groups of U.S. and Belgian physicists. The U.S. group will be under the direction of Dr. William S. Rodney, Georgetown University. The Belgium collaborator is Dr. J. Vervier, Institute for Nuclear Physics, Louvain, Belgium. The objective of this project is to carry out a program of experiments using radioactive beams to measure cross sections important to understanding nucleosynthesis. In novae, supernovae, X-ray bursters and possibly in the early universe, the temperature and density were such that the lifetimes of some radioactive (and isomeric) nuclides were comparable with the burning times for their destruction by proton- or alpha-particle-induced nuclear reactions. In these instances, these reactions must be taken into account in developing models for stellar evolution and nucleosyn- thesis. Thus, the potential for the use of radioactive targets and/or beams is receiving increasing attention in the nuclear physics community. In this project, the series of experiments outlined represent a major step in the direction of providing the needed cross section information. The Louvain-la-Neuve coupled cyclotron facility will be able to produce the required beam intensity to carry out these experiments. There are no existing U.S. facilities capable of such radioactive beam measurements. The research will benefit from Dr. Rodney's expertise in nuclear astrophysics and the background of his research group in active nuclear experimentation. The results of this research will contribute to our understanding of stellar evolution and nucleosynthesis in stars.