CAREER: Optical Single Atom Detection for Nuclear Astrophysics

该奖项支持光学显微镜的开发、建造和调试，该显微镜能够对冻结的霓虹膜中捕获的单个原子进行成像。最初，这台单原子显微镜将捕捉和计算在霓氦原子碰撞中产生的镁原子的数量。对这些罕见碰撞的详细测量将有助于解释铜、银和其他重化学元素的来源和丰度。由于单原子显微镜将把这类测量的灵敏度提高至少一百倍，模拟产生这些元素的恒星内部条件的实验室实验将首次成为可能。同时，PI将开发一个模块化的天文馆计划，描述恒星内部的化学元素是如何形成的。这些模块将在国家超导回旋实验室的虚拟之旅的背景下介绍，该实验室的研究如何影响我们对这一过程的理解，以及这项研究如何对社会有益。该项目的主要研究目标是开发和委托单原子显微镜来测量与核天体物理相关的罕见核反应。反冲产物将在惰性气体固体中被捕获，然后使用共振激光激发和单光子探测器进行光学探测。为镁设计的单原子显微镜，如果与反冲分离器相结合，将允许测量Ne-He核聚变反应，灵敏度至少提高100倍。这些反应在中子的产生中发挥了关键作用，中子的产生驱动了大质量恒星内部的慢中子俘获过程(S过程)，该过程负责产生质量在60到90之间的大约一半的重元素，包括铜和银。该项目的步骤包括演示固体Ne中Yb的光学单原子检测，校准该技术的效率、灵敏度和选择性，最后建造并调试一台单原子显微镜，用于测量产生镁原子的核反应。关键步骤包括详细了解各种光学元件中的杂质产生的光学背景、固体惰性气体中Yb和镁的光学光谱，以及设计一种高集光效率的衍射限制光学成像系统。

This award supports the development, construction, and commissioning of an optical microscope capable of imaging individual atoms that are captured inside a thin film of frozen neon. Initially, this single atom microscope will capture and count the number of magnesium atoms produced in collisions of neon and helium atoms. Detailed measurements of these rare collisions will help explain the origin and abundance of copper, silver, and other heavy chemical elements. Because the single atom microscope will increase the sensitivity of these types of measurements by at least a factor of one hundred, laboratory experiments that mimic the conditions inside of stars where these elements are produced will be possible for the first time. In parallel, the PI will develop a modular planetarium program that describes how the chemical elements are formed inside of stars. These modules will be presented within the context of a virtual tour of the National Superconducting Cyclotron Laboratory, which emphasizes how research being conducted at the Lab impacts our understanding of this process and how this research is beneficial to society.The primary research goal of this project is to develop and commission a single atom microscope for measuring rare nuclear reactions that are relevant for nuclear astrophysics. The recoil products will be captured within the noble gas solid and then optically detected using resonant laser excitation and single photon detectors. A single atom microscope designed for magnesium, when coupled with a recoil separator, would allow for measurements of neon-helium nuclear fusion reactions with at least a hundred fold improvement in sensitivity. These reactions play a key role in the production of neutrons that drives the slow neutron capture process (s-process) inside of massive stars, which is responsible for the creation of about half of the heavy elements between mass 60 and 90 including copper and silver. Steps for this project include demonstrating optical single atom detection of ytterbium in solid neon, calibrating the efficiency, sensitivity, and selectivity of the technique, and finally building and commissioning a single atom microscope for measuring the nuclear reactions that produce magnesium atoms. Critical steps include a detailed understanding of the optical backgrounds produced by impurities in the various optical components, optical spectroscopy of ytterbium and magnesium in solid noble gases, and the design of a high light collection efficiency diffraction-limited optical imaging system.