RUI: Structure and Dynamics of Negative Ions

负离子在各种物理过程中都很重要，包括地球大气、恒星大气、电放电和等离子体。这项研究计划的更广泛影响包括对原子性质数据库的贡献，与其他科学领域的联系，以及对本科生的教育和培训。激光将被用来测量负离子的性质，负离子是具有额外电子的原子和分子。因为离子是带电荷的粒子，所以可以操纵它们来进行精确的实验。本项目中电子结合能的高精度测量将有助于对半导体加工、照明和等离子体显示器等实际应用中的化学反应和等离子体相互作用进行建模。对负离子的详细研究将有助于深入了解动力学多体相互作用，这是物理、化学、材料科学和纳米技术等广泛领域的一个普遍感兴趣的话题。该项目将加强丹尼森大学这一本科学院的研究和教学基础设施。学生将参加校园内的实验，为年轻科学家提供重要的研究经验，包括电子、计算机、真空系统、激光和光学方面的技术培训。本项目在一系列脉冲激光光剥离实验中研究了光子与负离子的相互作用。负离子中的额外电子主要受电子关联效应的约束，因此负离子为关于这些多体相互作用的最先进的原子物理计算提供了肥沃的测试基础。在丹尼森大学的校园里，人们使用可调谐红外激光将外层电子从溅射源产生的负离子中分离出来，对复杂的原子负离子进行了研究。为了确定电子亲和势和能级，我们将测量几种稀土元素和第三类负离子(镧和铊)的基态和上态光剥离阈值。这些实验将有助于解释目前这些有趣体系的理论预测和实验光电子能谱结果之间的强烈不一致。教师和学生研究人员将研究稀土离子中的共振和束缚激发态，包括存在于La负离子中的束缚电子-偶极跃迁。更多的研究将研究碳链负离子的内壳层光脱离和两电子的光脱离过程。在高度关联的负离子核心的光激发和衰变过程中的动态多电子相互作用继续挑战着对原子结构的基本理解。该项目中的一系列实验将检验描述光分离和负离子结构的最新理论。

Negative ions are important in a variety of physical processes including Earth's atmosphere, stellar atmospheres and electrical discharges and plasmas. The broader impacts of this research program include contributions to the database of atomic properties, connections to other scientific fields, and the education and training of undergraduate students. Lasers will be used to measure the properties of negative ions, which are atoms and molecules that have an extra electron. Since ions are electrically charged particles, they can be manipulated to allow precise experiments. The high-precision measurements of electron binding energies in this project will be useful for modeling of chemical reactions and plasma interactions for such practical applications as semiconductor processing, lighting and plasma displays. The detailed studies of negative ions will yield insights into dynamical many-body interactions, which is a general topic of interest for a broad range of fields in physics, chemistry, materials science, and nanotechnology. The project will enhance the research and teaching infrastructure of Denison University, an undergraduate college. Students will participate in the experiments on-campus, providing important research experiences for young scientists including technical training in electronics, computers, vacuum systems, lasers, and optics. This project studies the interactions of photons with negative ions in a series of pulsed-laser photodetachment experiments. The extra electron in a negative ion is bound predominantly by electron correlation effects and therefore negative ions provide a fertile testing ground for state-of-the-art atomic physics calculations regarding these multi-body interactions. Complex atomic negative ions are investigated on-campus at Denison University using tunable infrared laser light to detach outer-shell electrons from negative ions produced in a sputter source. The ground and upper state photodetachment thresholds of several lanthanide and Group III negative ions (Lanthanum and Thallium) will be measured in order to determine the electron affinities and energy levels. These experiments will help explain the current strong disagreement between theoretical predictions and experimental photoelectron spectroscopy results for these interesting systems. The faculty and student researchers will investigate resonances and bound excited states in lanthanide ions including bound-bound electric-dipole transitions that exist in the negative ion of La. Additional studies will investigate inner-shell photodetachment from carbon chain negative ions and two-electron photodetachment processes. The dynamic multi-electron interactions in the photoexcitation and decay of the highly correlated cores of negative ions continue to challenge the fundamental understanding of atomic structure. The series of experiments in this project will test the latest theories describing photodetachment and negative ion structure.