MRI: Acquisition of a Frequency Quadrupled Titanium Sapphire Laser

非技术性说明：这笔赠款支持史密斯学院（一所女子文科大学）购置一套激光系统。 该系统将实现两项主要发展，第一项是下一代称为"原子阱痕量分析"的技术，预计将大大提高美国监测已知和可疑核后处理场地活动的能力，以及分析用于气候历史研究的冰芯样本的能力。 第二个发展涉及高精度测量中性铍的几个能级，这提高了我们对原子理论的理解，有助于推进基础科学。技术说明：为了对氪进行痕量分析（支持上段所述的第一项发展），氪原子首先需要被转移到亚稳态，以便进行激光冷却和捕获。 大多数原子阱痕量分析测量的精度目前受到用于产生亚稳态原子束的方法的限制。 用这里资助的光源取代这些方法将带来显著的进步，例如提高检测效率，减少样品大小，消除交叉样品污染。 铍项目（上段所述的第二项发展）旨在改进对若干能级和电离阈值的实验测量。 目前，能级的理论估计比实验测量精确一个数量级以上。 这些改进的实验结果将描绘各种理论模型，测试量子电动力学，并帮助确定铍的核电荷半径。

Non-technical description:This grant supports the acquisition of a laser system at Smith College, an undergraduate women's liberal arts college. This system will enable two main developments, the first of which is the next generation of a technique called "Atom Trap Trace Analysis (ATTA)" which is expected to significantly improve the ability of the U.S. to monitor activity at known and suspected nuclear reprocessing sites, as well as to analyze ice core samples for climate history studies. The second development involves the measurement of several energy levels of neutral beryllium to high precision, which improves our understanding of atomic theory and helps to advance basic science. Technical description:To perform trace analysis with krypton (in support of the first development described in the paragraph above), krypton atoms first need to be transferred to a metastable state for laser cooling and trapping. The precision of most Atom Trap Trace Analysis measurements is currently limited by the methods used to produce the metastable atomic beams. Replacing these methods with the optical source funded here will lead to significant advances such as an increase in detection efficiency, a decrease in sample size, and elimination of cross-sample contamination. The beryllium project (the second development described in the paragraph above) aims to improve experimental measurements on several energy levels and the ionization threshold. Currently, theoretical estimates of the energy levels have more than an order of magnitude more precision than experimental measurements. These improved experimental results will delineate various theoretical models, test quantum electrodynamics, and help determine the nuclear charge radius of beryllium.