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.

该职业奖支持对铍 (Be) 作为下一代光学原子钟的新候选元素以及用于产生超冷中性等离子体（离子和电子的超冷气体）的研究。原子钟在二十世纪科学技术的进步中发挥了重要作用，带来了全球定位、先进通信和粒子物理基础理论测试等创新。下一代光学原子钟将扩展这些系统的功能，并将增强数据路由和通信的安全性、先进的基于地球和空间时间的导航以及对爱因斯坦广义相对论的更精确的测试。超冷中性等离子体 (UCNP) 是激光产生的等离子体，它突破了传统等离子体物理学的界限。 然而，对这些台式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存在的更热、更密的等离子体的理解。该项目的目标是激光冷却、捕获和光电离中性原子铍，使其可用作光学频率标准，并在足够低的温度下生产UNCP，以便离子晶体在系统内形成，从而几乎冻结等离子体。 该奖项还将有可能吸引和留住更多代表性不足的少数族裔学生来学习物理。 该项目将涉及现有大学的少数族裔研究生、本科生和高中生。阿拉巴马州 - 伯明翰计划参与 Simien 光谱和激光冷却小组的研究项目。其他外展活动旨在通过在该地区当地学校进行物理和化学演示来提高 K-12 学生对科学和工程的兴趣。该项目是一个实验项目，旨在研究原子铍的光谱、激光冷却和光电离特性，因为它与原子钟和超冷中性等离子体有关。 Be是一种碱土元素，具有简单的内部结构，可在中性原子和离子的光学区域中提供电偶极和相互组合跃迁。 它是下一代频率标准以及激光冷却、捕获和光电离产生超冷等离子体的有前途的候选者。特别是，光谱研究将涉及强电偶极子跃迁超精细结构的测量。本研究的目的是确定 Be 超精细常数，该常数定义超精细峰的排序以及磁偶极子和电四极子相互作用对能量转移的贡献。确定这种光谱特性对于实现铍的激光冷却和捕获是必要的。此外，激光冷却和捕获将用于创建磁光陷阱，作为对组合线进行精确测量的第一步。 它还将用于光电离研究，以生成铍基频率标准和超冷中性等离子体，可以有效地激光冷却到强耦合状态。 该项目由等离子体物理项目、原子、分子和光学实验物理项目以及刺激竞争研究既定项目 (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价值和更广泛的影响审查标准进行评估，被认为值得支持。