WoU-MMA: Nuclear Physics at the Notre Dame Nuclear Science Laboratory Providing a Window on the Universe

这一奖项延续了圣母大学核结构物理和核天体物理八名教职员工及其学生的研究计划。该计划的重点是直接测量核反应和衰变过程，这些过程决定了恒星的寿命、元素的起源，以及提供宇宙窗口的多信使的产生。该计划解决了定义恒星演化和爆炸过程的时间尺度的关键核过程。另一个组成部分是研究超新星爆炸前恒星生命最后几天的低能聚变反应。该计划还探索了指导大规模核合成过程的核结构效应。这项研究主要是利用圣母大学核科学实验室(NSL)的加速器进行的，这些加速器是专门为通过一些实验技术探测恒星反应而设计的。实验结果扩大了我们对原子核作为多体量子系统的基本结构的认识；它们也为天体物理学界提供了关于元素起源和宇宙从大爆炸到现在的化学演化的新见解。NSL是在大学环境中进行这类研究的独特设备。该奖项将支持对大量研究生(约25名)和本科生(约20名)进行实验和理论技术方面的培训，以便为加入国家核工作队伍做好准备。该实验计划基于NSL使用两个加速器。用单端5U Pelletron产生的强稳定离子束直接研究了低能俘获和聚变反应。利用圣乔治反冲分离器的逆运动学技术，用重离子束研究了这类反应。这种分离器是独一无二的，是FRIB SECAR分离器设计的蓝图。FN串列加速器是一种多功能仪器。它被用作新扩建的TriSol设施生产放射性束流的驱动器，TriSol设施是美国第一台生产低能放射性束流的专用仪器。这些束流允许对轻放射性粒子进行直接反应测量和捕获，其水平在大型国家设施中是不可能的。FN还为NSL的加速器质谱仪(AMS)计划提供服务，测试地质和宇宙样品的长期放射性。大量的核结构实验都是基于这台机器的操作，使用了各种粒子和伽马能谱技术。该计划的一小部分依赖于使用其他国家和国际设施，以利用NSL无法获得的更高能量和更奇特的光束。该项目推进了未来NSF投资的十大想法之一“宇宙之窗：多信使天体物理时代”的目标。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award continues the research program of eight faculty members and their students in Nuclear Structure Physics and Nuclear Astrophysics at the University of Notre Dame. The program focuses on direct measurements of nuclear reaction and decay processes that determine the life of stars, the origin of the elements, and production of multi messengers that provide a Window on the Universe. This program addresses key nuclear processes that define the timescales of stellar evolution and explosion processes. Another component is the study of low energy fusion reactions during the last days of a stellar life prior to supernova explosion. The program also explores the nuclear structure effects that are guiding large scale nucleosynthesis processes. The research is performed primarily by using the accelerators of the Nuclear Science Laboratory (NSL) at the University of Notre Dame, which are uniquely designed to probe stellar reactions through a number of experimental techniques. The experimental results expand our knowledge of the fundamental structure of the nucleus as a multi-body quantum system; they also provide new insight for the astrophysics community on the origin of the elements and the chemical evolution of the cosmos from the Big Bang to the present. The NSL is uniquely equipped for performing this kind of research in a university environment. The award will support the training of a large number of graduate (approximately 25) and undergraduate students (approximately 20) in experimental and theoretical techniques to be ready to join the nuclear workforce of the nation.The experimental program is based on the use of two accelerators at the NSL. Intense stable ion beams from the single ended 5U Pelletron are used for the direct study of low-energy capture and fusion reactions. Heavy ion beams are used to investigate such reactions in inverse kinematic technique using the St. GEORGE recoil separator. This separator is unique and serves as a blueprint for the design of the SECAR separator at FRIB. The FN tandem accelerator is used as a multi-purpose instrument. It is operated as a driver for the production of radioactive beams at the newly-expanded TriSol facility, the nation's first dedicated instrument for producing low energy radioactive beams. These beams allow direct reaction measurements with and the trapping of light radioactive particles at levels not possible at large national facilities. The FN also serves the accelerator mass spectrometry (AMS) program at the NSL, testing geological and cosmological samples for long-lived radioactivities. A large number of nuclear structure experiments are based on the operation of this machine using a variety of particle and gamma spectroscopy techniques. A smaller fraction of the program relies on the use of other national and international facilities to take advantage of higher energy and more exotic beams not available at the NSL.This project advances the objectives of "Windows on the Universe: the Era of Multi-Messenger Astrophysics", one of the 10 Big Ideas for Future NSF Investments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.