Equipment: MRI: Track 1 Acquisition of a Laser System for High Precision Spectroscopy and Trapping Neutral Holmium

设备： MRI：轨道 1 获取用于高精度光谱和捕获中性钬的激光系统

• 批准号: 2319917
• 负责人: William Raven
• 金额: $ 33万
• 依托单位: Smith College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2319917&HistoricalAwards=false
• 关键词: Equipment; MRI; Track; Acquisition; Laser

This grant supports the acquisition of a laser system to perform fundamental atomic physics research at Smith College. The research group is studying the complex interactions and inner workings of the atom. The best theoretical model of atomic systems is known as the Standard Model of Particle Physics. It is a very successful model, but we know it is not complete. For example, the Model does not include gravity or dark matter. Dark matter is a substance which astronomical observations indicate makes up 25% of the universe, but we know very little about. Two methods of improving our understanding of atomic systems are to work within the framework of the Model (known as testing the Model) or to work outside that framework (known as physics beyond the Standard Model). This laser system will enable this research group to use both methods in two independent projects. The first, which works within the Model, will perform experimental measurements on the light atoms beryllium, boron, nitrogen, and oxygen. Comparing these results to ongoing theoretical work from other groups will both test the validity of these complicated theoretical methods and, combined with the theoretical results, serve as a test of the Model. The second project, which works outside the Model, is to look for dark matter interaction with an isotope of holmium known as 166m-holmium. It is theorized that dark matter might cause an interaction with the nucleus that, if that interaction occurs, can be detected. The goal is to build a sensitive apparatus that will either detect this interaction or conclude this idea is not valid. In addition to this scientific impact, the Raven lab will continue to include a large number of undergraduate researchers through traditional lab projects and senior theses as well as our new course-based research experience (CURE). The goal of the CURE is to 1) provide a robust research experience for twelve undergraduate students each year and 2) train the next generation of scientists to perform high precision spectroscopy.The Raven lab will use this new laser system to measure the absolute transition frequencies as well as hyperfine coupling constants, when applicable, of a variety of states in the light atoms to provide invaluable feedback to theorists who are in the pursuit of developing high precision multi-electron models. Combined with theoretical predictions, the results will serve to test the accuracy of quantum electrodynamics. Planned spectroscopic measurements will be performed on a number of triplet states in neutral beryllium-9, two transitions in the stable isotopes of boron, and a variety of states in nitrogen and oxygen. In addition, the Raven lab will develop an atom trap trace analysis (ATTA) apparatus for holmium atoms. 166-Ho is short lived while the metastable 166m-Ho state is long lived. Starting with a sample of only 166m-Ho atoms, ATTA will look for induced dark matter decay of 166m-Ho to the nuclear ground state. This new ATTA could also assist in the Electron Capture 163-Ho (ECHo) experiment, where 166m-Ho is a contaminant.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.

这笔拨款支持获得激光系统，在史密斯学院进行基础原子物理研究。这个研究小组正在研究原子的复杂相互作用和内部工作原理。原子系统的最佳理论模型被称为粒子物理学的标准模型。这是一个非常成功的模式，但我们知道它并不完整。例如，该模型不包括引力或暗物质。暗物质是一种物质，天文观测表明它占宇宙的25%，但我们对它知之甚少。提高我们对原子系统理解的两种方法是在模型框架内工作（称为测试模型）或在该框架外工作（称为标准模型之外的物理学）。这个激光系统将使这个研究小组在两个独立的项目中使用这两种方法。第一个在模型内工作，将对轻原子铍、硼、氮和氧进行实验测量。将这些结果与其他小组正在进行的理论工作进行比较，既可以检验这些复杂的理论方法的有效性，又可以结合理论结果作为对模型的检验。第二个项目在模型之外工作，是寻找暗物质与一种被称为166m-holmium的同位素之间的相互作用。从理论上讲，暗物质可能会引起与原子核的相互作用，如果这种相互作用发生，就可以被探测到。目标是建立一个灵敏的仪器，要么检测到这种相互作用，要么得出这个想法是无效的结论。除了这种科学影响之外，Raven实验室将通过传统的实验室项目和高级论文以及我们新的基于课程的研究经验（CURE）继续包括大量的本科生研究人员。CURE的目标是1)每年为12名本科生提供强大的研究经验，2)培养下一代科学家进行高精度光谱学。Raven实验室将使用这种新的激光系统来测量光原子中各种状态的绝对跃迁频率以及超精细耦合常数，当适用时，为追求开发高精度多电子模型的理论家提供宝贵的反馈。结合理论预测，结果将用于测试量子电动力学的准确性。计划中的光谱测量将对中性铍-9的一些三重态、硼的稳定同位素的两个跃迁以及氮和氧的各种状态进行。此外，Raven实验室将开发一种用于钬原子的原子陷阱痕量分析（ATTA）设备。166-Ho态寿命短，而亚稳的166-Ho态寿命长。ATTA将从一个只有166m-Ho原子的样本开始，寻找由166m-Ho诱导的暗物质衰变到核基态。这种新的ATTA也可以辅助电子捕获163-Ho （ECHo）实验，其中166m-Ho是一种污染物。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。