CAREER:Laser Cooling and Trapping of Beryllium: Frozen Plasmas and Precision Measurements

职业：铍的激光冷却和捕获：冷冻等离子体和精密测量

• 批准号: 1848154
• 负责人: Clayton Simien
• 金额: $ 48.35万
• 依托单位: University of Alabama at Birmingham
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1848154&HistoricalAwards=false
• 关键词: CAREER; Laser; Cooling; Trapping; Beryllium

This CAREER award supports investigation of berillium (Be) as a new candidate element for the next generation of optical atomic clocks, as well as for producing an ultracold neutral plasma -- an ultracold gas of ions and electrons. Atomic clocks have been instrumental in the advancement of science and technology in the twentieth century, leading to innovations such as global positioning, advanced communications, and tests of fundamental theories of particle physics. A next generation optical atomic clock would extend the capabilities of these systems and will enable enhanced security for data routing and communications, advanced earth and space time-based navigation, and ever more precise testing of Einstein's Theory of General Relativity. Ultracold neutral plasmas (UCNPs) are laser produced plasmas that stretch the boundaries of traditional plasma physics. However, studies of these table-top ultracold systems are promising to greatly improve our understanding of much hotter and denser plasmas thought to occur in many astrophysical systems. The goal of this project is to laser cool, trap and photo-ionize neutral atomic beryllium for its potential use as an optical frequency standard, and to produce a UNCP at a sufficiently low temperature for ionic crystals to form inside the system, virtually freezing the plasma. This award will also make it possible to attract and retain more underrepresented minority students to physics studies. The project will involve minority graduate, undergraduate, and high school students via existing Univ. of Alabama - Birmingham programs to participate in research projects in the Simien Spectroscopy and Laser Cooling group. Additional outreach activities will aim to get K-12 students interested in science and engineering by performing physics and chemistry demonstrations at local schools in the region.This project is an experimental program directed towards investigation of spectroscopic, laser cooling, and photoionization properties of atomic beryllium as it relates to atomic clocks and ultracold neutral plasmas. Be is an alkaline earth element with a simple internal structure which provides for electric-dipole and intercombination transitions in the optical regions for both neutral atoms and ions. It is a promising candidate for next generation frequency standards and for laser cooling, trapping, and photo-ionization to produce an ultracold plasma. In particular, the spectroscopic studies will involve measurements of the hyperfine structure of strong electric dipole transitions. The objective of this study is to determine Be hyperfine constants, which define the ordering of the hyperfine peaks and contributions to the energy shifts from the magnetic dipole and electric quadrupole interactions. The determination of this spectroscopic property is necessary for implementing laser cooling and trapping of beryllium. In addition, laser cooling and trapping will be used to create a magneto-optical trap as the first step towards performing precision measurements on the intercombination lines. It will also be used for photoionization studies for generation of a Be based frequency standard and an ultracold neutral plasma that can be efficiently laser cooled into the strongly coupled regime. This project is jointly funded by the Plasma Physics program, the Atomic, Molecular and Optical Experimental Physics program, and the Established Program to Stimulate Competitive Research (EPSCoR).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.

该职业奖支持将铍(Be)作为下一代光学原子钟的新候选元素以及生产超冷中性等离子体--一种由离子和电子组成的超冷气体--的研究。原子钟在二十世纪的科学和技术进步中发挥了重要作用，导致了全球定位、先进通信和粒子物理基本理论测试等创新。下一代光学原子钟将扩展这些系统的能力，并将增强数据路由和通信的安全性，先进的基于地球和时空的导航，以及对爱因斯坦广义相对论的更精确测试。超冷中性等离子体(UCNP)是一种激光产生的等离子体，它延伸了传统等离子体物理学的边界。然而，对这些桌面超冷系统的研究有望极大地提高我们对许多天体物理系统中发生的更热、更密集的等离子体的理解。该项目的目标是激光冷却、捕获和光电离中性原子铍，使其有可能用作光学频率标准，并在足够低的温度下产生UNCP，以便在系统内形成离子晶体，实际上冻结了等离子体。这一奖项还将使吸引和留住更多未被充分代表的少数族裔学生攻读物理学成为可能。该项目将通过现有的大学吸引少数民族研究生、本科生和高中生。亚拉巴马州-伯明翰分校参与西米恩光谱学和激光冷却小组的研究项目。其他外展活动将旨在通过在当地学校进行物理和化学演示来吸引K-12学生对科学和工程感兴趣。这个项目是一个实验计划，旨在研究与原子钟和超冷中性等离子体有关的铍原子的光谱、激光冷却和光致电离性质。Be是一种碱土元素，具有简单的内部结构，为中性原子和离子提供了光学区的电偶极跃迁和组合间跃迁。它是下一代频率标准和激光冷却、俘获和光电离产生超冷等离子体的有前途的候选者。特别是，光谱研究将涉及测量强电偶极跃迁的超精细结构。这项研究的目的是确定Be超精细常数，它定义了超精细峰的顺序以及对磁偶极相互作用和电四极相互作用所产生的能量移动的贡献。这种光谱性质的测定是实现铍的激光冷却和捕获所必需的。此外，激光冷却和捕获将被用来创建磁光陷阱，作为在相互结合线上进行精确测量的第一步。它还将用于光电离研究，以产生基于Be的频率标准和可以有效地激光冷却到强耦合区域的超冷中性等离子体。该项目由等离子体物理计划、原子、分子和光学实验物理计划以及既定的激励竞争研究计划(EPSCoR)共同资助。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。