Electron-Atom Scattering Dynamics

电子原子散射动力学

• 批准号: 46455-2006
• 负责人: Zetner, Peter
• 金额: $ 3.45万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=390661
• 关键词: Electron; Atom; Scattering; Dynamics

In 1914, J. Franck and G. Hertz performed an experiment which played a vital role in establishing modern atomic theory.  That experiment, for which they won the Nobel Prize in 1925, examined the collisions of electrons with mercury atoms.  The field of electron-atom (molecule) scattering has grown enormously, both in sophistication and importance, since that first study.  The growing importance of this field arises from the discovery of numerous and diverse natural phenomena, as well as technological processes, which involve electron-atom (molecule) collisions.  The immense spectrum of relevant phenomena includes processes occurring in the upper atmospheres of the planets, processes occurring in fusion plasmas, techniques applied to the fabrication of semiconductor devices and occurrence of radiation damage in living tissue.  Complete understanding of these phenomena and the further development of the relevant technological processes requires the quantitative characterization of electron scattering from the atoms (molecules) of interest and supplies the motivation for the continued study of this field in the laboratory.   In this grant application, funding is being requested to support an ongoing program in the experimental investigation of electron collisions with atoms and molecules.  Our primary interest is currently focused on collision phenomena involving excited-state atomic targets, a field which remains largely undeveloped but is of great practical value in plasma studies.  Our method involves pre-excitation of the atomic target by laser radiation and the measurement of collision processes involving this pre-excited target.  Such techniques are developing rapidly as important tools in collision studies where lasers can be utilized as a means to control and probe collision reactions.  In our case, in addition to providing an efficient mechanism for the production of high concentrations of excited scattering targets, the use of laser radiation allows us to prepare the excited atom in a "pure quantum state".  We can thereby elucidate the physics of the collision process and make the connection with new theoretical models at the most fundamental level possible.

1914年，J.Franck和G.赫兹做了一个实验，这个实验对建立现代原子理论起了至关重要的作用。这个实验检验了电子与汞原子的碰撞，他们因此获得了1925年的诺贝尔奖。（分子）散射在复杂性和重要性方面都有了巨大的发展，这一领域重要性日益增加是因为发现了许多不同的自然现象以及技术过程，其中涉及电子原子（分子）碰撞。相关现象的巨大范围包括行星高层大气中发生的过程，聚变等离子体中发生的过程，半导体器件的制造技术和生物组织的辐射损伤。对这些现象的全面了解和相关技术的进一步发展，该过程需要从感兴趣的原子（分子）散射的电子的定量表征，并为在实验室中继续研究该领域提供动力。 在这项资助申请中，我们要求资助一项正在进行的计划，即电子与原子和分子碰撞的实验研究。我们的主要兴趣目前集中在涉及激发态原子靶的碰撞现象上，这一领域在很大程度上尚未开发，但在等离子体研究中具有很大的实用价值。用激光辐射激发原子靶和测量涉及这种预激发靶的碰撞过程。这种技术作为碰撞研究中的重要工具正在迅速发展，其中激光可以用作控制和探测碰撞反应的手段。在我们的情况下，除了提供一种产生高浓度激发散射靶的有效机制外，激光辐射的使用还使我们能够制备处于“纯量子态”的激发原子，从而阐明碰撞过程的物理学，并在最基本的水平上与新的理论模型建立联系。