RUI: The Interaction of Radiation with Free and Confined Quantum Systems

RUI：辐射与自由量子系统和受限量子系统的相互作用

• 批准号: 1305085
• 负责人: Valeriy Dolmatov
• 金额: $ 9.75万
• 依托单位: University of North Alabama
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2016-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1305085&HistoricalAwards=false
• 关键词: RUI; Interaction; Radiation; Free; Confined

The response of a physical system to incoming electromagnetic radiation or charged particles is one of the most basic properties of nature of utter importance to both fundamental and applied sciences along with a wide variety of technological applications. Despite numerous studies of these processes performed to date, the current understanding of them is far from complete. This is because the processes are multifaceted in the richness of phenomena that might occur, and are extremely difficult for theory to embrace all of them, or even some of them. In this project, the understanding of the structure and spectra of free and confined atoms and their interactions with incoming electromagnetic radiation or charged particles will be advanced. In the project, confined atoms of interest are defined as atoms which are embedded into hollow interiors of various gas-phase fullerenes Cn or other types of penetrable and impenetrable confinements with varying heights and widths, as well as positioned near planar or non-planar graphitic nano-structures. New trends in the cross sections of corresponding processes of photon absorption and collision of the incoming electrons with confined and free atoms will be unveiled. For free atoms, this will be achieved by accounting for the interactions mixing a 'pure' vacancy state (such, e.g., as 5s in Ba) or 'pure' incoming particle state with dominant (to be determined in the project) higher order continuous state excitations in a number of atoms, in the first hand in Ba and Mn; so far, the needed understanding is lacking. For confined atoms, new trends in their spectra will be unraveled by accounting for individual and combined effects brought about by the above specified confinements of different properties and geometry, by varying positions of the confined atom inside a confinement, and by accounting for multielectron interactions (electron correlation) in the atom itself. Hartree-Fock approximation, random phase approximation with exchange, methods of many-body perturbation theory, etc., will be employed in, or adjusted to, the stated studies. The intellectual merit of activities to be performed is determined by the fact that to date there is little knowledge on how the individual and combined effects of nano-scaled confinements of different symmetries (spherical, non-spherical, homogeneous, inhomogeneous, planar, non-planar, etc.) may alter the structure and spectra of confined in, or positioned near them atoms. Also, to date, there remains a lack of understanding of the interactions mixing pure vacancy/particle states in an atom with its higher order excitations. Moreover, results of the project will identify some of the most interesting and/or useful future measurements/calculations which could be performed, both for free and confined atoms, thereby contributing synergy to advancement of the field. On a broader impact scale, the involvement and active participation of undergraduate students in this project will strengthen integration of research and education at the University. Furthermore, the project will enhance the research infrastructure in the University. Results of research will be disseminated broadly to scientific community and general public for a broader awareness of science. Society will benefit from the performed activities by gaining new fundamental knowledge on phenomena of nature with important applications, and by the training of students who, early in their careers, will have acquired a unique professional experience for entry into graduate study in physics or scientific and engineering careers. All of the above will significantly contribute to the benefit, health, vitality of science and engineering, and the prosperity of society.

物理系统对入射的电磁辐射或带电粒子的响应是自然界最基本的性质之一，对基础科学和应用科学以及各种技术应用都具有极其重要的意义。尽管迄今为止对这些过程进行了许多研究，但目前对它们的理解还远远不完整。这是因为这些过程在可能发生的现象的丰富性方面是多方面的，理论极难涵盖所有现象，甚至部分现象。在这个项目中，将促进对自由和约束原子的结构和光谱以及它们与入射电磁辐射或带电粒子的相互作用的理解。在该项目中，感兴趣的受限原子被定义为嵌入各种气相富勒烯CN或其他类型的高度和宽度不同的可穿透和不可穿透的约束的中空内部，以及位于平面或非平面的石墨纳米结构附近的原子。光子吸收和入射电子与受限原子和自由原子碰撞的相应过程的横截面的新趋势将被揭示。对于自由原子，这将通过考虑相互作用来实现，在一些原子中，首先是在Ba和Mn中，将‘纯’空位态(例如，Ba5s)或‘纯’入射粒子态与主要的(将在项目中确定的)更高阶连续态激发混合在一起；到目前为止，还缺乏必要的理解。对于受限原子，其光谱中的新趋势将通过考虑上述不同性质和几何的特定约束所带来的单独和组合效应、通过改变受限原子在约束中的位置以及通过考虑原子本身中的多电子相互作用(电子关联)来揭示。Hartree-Fock近似、交换随机位相近似、多体微扰理论等方法将被用于或调整到所述研究中。要开展的活动的智力价值取决于这样一个事实，即到目前为止，关于不同对称性(球形、非球形、均质、非均质、平面、非平面等)的纳米尺度限制的单独和综合影响的知识很少。可以改变限制在原子中或位于原子附近的原子的结构和光谱。此外，到目前为止，人们仍然缺乏对原子中纯空位/粒子态与其高阶激发的相互作用的了解。此外，该项目的结果将确定一些未来可以进行的最有趣和/或最有用的测量/计算，包括对自由原子和受限原子的测量/计算，从而促进该领域的进步。在更广泛的影响范围内，本科生对这一项目的参与和积极参与将加强大学研究和教育的整合。此外，该项目将加强大学的研究基础设施。研究成果将广泛传播给科学界和公众，以提高人们对科学的认识。社会将从所开展的活动中受益，因为它获得了关于具有重要应用的自然现象的新的基本知识，并通过培训那些在其职业生涯早期将获得进入物理学或科学和工程专业研究生学习的独特专业经验的学生。所有这些都将为科学和工程的造福、健康、活力和社会繁荣做出重大贡献。