Operation of the NSCL as a National User Facilty & Research Program

该奖项提供资金用于运行和维护密歇根州立大学（MSU）的国家超导回旋实验室（NSCL）作为国家用户设施，支持核结构，核天体物理学，基本参数和对称性的精确测量以及加速器科学方面的国外项目，并支持密歇根州核科学学院的研究项目。该奖项将通过支持NSCL作为致力于稀有（短寿命）同位素生产和研究的国家首要用户设施的运作，继续NSCL在这些领域的国内和国际领导地位。该奖项还将使国家科学实验室能够利用最近投入使用的世界上唯一的querea3束线加速器提供的科学机会，该加速器可以在尚未用同位素探索过的能量下进行实验，并且与超新星和原子核结构相关。这些机遇与2015年国家科学委员会长期计划的科学目标有很强的重叠，并形成了一个连贯的轨迹，朝着国家科学实验室正在建设的下一代加速器——FRIB。在国家科学学院进行研究的人员中约有80%来自外大，国家科学学院的支持将服务于广泛的科学界。作为美国最大的基于大学的核物理用户设施，国家核物理实验室将继续为培养下一代核科学家、加速器物理学家和工程师提供独特的动手学习机会。在美国获得的所有核科学博士学位中，约有10%是基于在国家科学实验室进行的研究，每年约有100名本科生积极参与国家科学实验室的研究。该实验室有广泛的外联活动，包括每年4000多人的设施参观。此外，研究还在应用领域进行，如癌症放射治疗新工具的开发，电离辐射如何影响DNA的系统研究，复杂材料中新型原子和纳米结构的发现，以及国土安全。稳定同位素的强光束使用国家科学实验室的两个耦合超导回旋加速器CCF进行加速。当光束击中一个静止的目标时，原子核分裂成碎片。每个碎片本身就是一个较轻的原子核，许多碎片本身就是寿命较短的同位素。一个特定实验所选择的同位素是通过碎片分离器来选择的：一种只允许特定电荷和质量通过其路径的磁力分离器。从碎片分离器中产生的原子核形成新的光束，用于研究各种核反应。scl有7个端站，同位素束可以定向，每个端站都有各种目标和探测器系统，以进行所需的测量。NSCL还可以使用致密气体使不稳定同位素完全停止；这反过来又使原子和分子物理学中使用的捕获技术的质量测量等实验成为可能。ReA3束线加速器将停止的同位素重新加速到低能量（远低于飞行中的水平），用于对核天体物理学很重要的实验，包括恒星能量产生的起源以及恒星诞生和死亡的动力学。因此，加速光束被引导到其中一个终端站，用于各种核反应。

This award provides funds to operate and maintain the National Superconducting CyclotronLaboratory (NSCL) at Michigan State University (MSU) as a national user facility, to support abroad program in nuclear structure, nuclear astrophysics, precision measurements of fundamentalparameters and symmetries, and accelerator science, and to support the research programs of MSUnuclear science faculty. The award will continue NSCL's national and international leadership inthese areas by supporting its operation as the nation's premier user facility dedicated to theproduction and study of rare (short-lived) isotopes. The award will also allow the NSCL to exploitthe scientific opportunities newly available with the recently commissioned and world-uniqueReA3 beamline accelerator that enables experiments at energies that have not been explored withrare isotopes and are relevant to supernovae and the structure of nuclei. These opportunities havestrong overlap with the stated scientific goals of the 2015 NSAC Long Range Plan, and form acoherent trajectory towards the next generation accelerator, FRIB, which is being constructed onthe NSCL site. Approximately 80% of those conducting research at the NSCL are from outsideMSU and the support of NSCL will serve a broad scientific community. As the nation's largestuniversity-based user facility for nuclear physics, the NSCL will continue to provide unique handsonlearning opportunities for educating the next generation of nuclear scientists, acceleratorphysicists, and engineers. Approximately 10% of all nuclear science PhDs awarded in the UnitedStates are based on research carried out at the NSCL, and approximately 100 undergraduatestudents are actively involved in research at the NSCL each year. The laboratory has extensiveoutreach activities, including facility tours for over 4000 people each year. In addition, researchis carried out in application areas such as development of new tools for radiation treatments ofcancer, systematic studies of how ionizing radiation affects DNA, discovery of novel atomic andnanostructures in complex materials, and homeland security.Intense beams of stable isotopes are accelerated using the NSCL's two coupled superconductingcyclotrons, the CCF. The nuclei split into fragments as the beam strikes a stationary target. Eachfragment is itself a lighter nucleus, and many fragments are themselves short-lived isotopes. Theisotope of choice for a specific experiment is selected by means of a fragment separator: a magneticchicane that permits only a specific charge and mass through its pathway. The nuclei emergingfrom the fragment separator form a new beam for use in studying various nuclear reactions. TheNSCL has seven end stations to where the isotope beam can be directed and each end station hasa variety of target and detector systems to carry out the desired measurements. The NSCL canalso bring the unstable isotopes to a complete stop using a dense gas; this in turn enablesexperiments such as mass measurements using trapping techniques also used in atomic andmolecular physics. The ReA3 beamline accelerator reaccelerates stopped isotopes to low energies(well below in-flight levels) for experiments that are important for nuclear astrophysics, includingthe origin of stellar energy production as well as the dynamics of the birth and death of stars. Thereaccelerated beams are directed to one of the end stations for use in various nuclear reactions.