Mean-Field Techniques for Atomic Collision Theory (Physics)

平均场理论在原子中的初步应用 碰撞表明，它处理好一些 在离子束的基展开技术中遇到的困难， 原子散射 该理论的一些优点是（i） 它为模型开发提供了直观的图片， 机制的阐明，（二）容易与连续 （三）许多国家都有自己的国家， 体效应被包括在过渡矩阵元素中。 由于最初的结果是如此令人鼓舞， 建议扩大这一技术的通用性和范围 使其适用于更广泛的问题。 适当的 框架已经开发和测试，提供 从量子电子度的瞬时耦合 经典核自由度。 当这个 已被纳入离子原子碰撞计划， 已经开发了一些三维能力，它将 可以解决各种问题，如化学 反应和离子表面散射，除了问题 低能量（绝热）离子-原子电荷交换。 该研究小组将运用其行之有效的 技术的数值解的时间依赖 薛定谔方程，以获得更好的理解 原子或离子与金属表面之间的相互作用。 的 拟议工作的目标是汇集国家- 对于时间依赖性行为的现有技术描述 原子（TDHF）、轨道（CQC）和表面（jeltron）， 获得原子表面的最佳描述 交互. 这个团体是唯一有资格 对电荷交换散射的显著贡献 在相对较短的时间内浮出水面。 这项研究工作 应该为所使用的某些参数提供可靠的值 在目前的模式中，关于有效性范围的指导 某些模型，和直观的图片， 原子-表面相互作用

Initial application of mean-field theory to atomic collisions has indicated that it handles well some of the difficulties encountered in basis expansion techniques for ion- atom scattering. Some of the strengths of the theory are (i) that it provides intuitive pictures for model development and mechanism elucidation, (ii) the ease with which continuum intermediate states are included, and (iii) the fact that many- body effects are included in the transition matrix elements. Since the initial results were so encouraging, it is proposed to broaden the generality and scope of this technique to make it applicable to a wider variety of problems. A proper framework has been developed and tested to provide instantaneous coupling from the quantum electronic degrees of freedom to the classical nuclear degrees of freedom. When this has been incorporated into the ion-atom collision program, and some three-dimensional capability has been developed, it will be possible to address a variety of topics such as chemical reactions and ion-surface scattering, in addition to problems in low-energy (adiabatic) ion-atom charge exchange. This research group will apply its well-established techniques for numerical solution of the time-dependent Schrodinger equation to obtain a better understanding of the interaction between an atom or ion and a metal surface. The objective of the proposed work is to bring together state-of- the-art descriptions for the time-dependent behavior of the atom (TDHF), the trajectory (CQC) and the surface (jellium) to obtain the best available description of atom-surface interactions. The group is uniquely qualified to make significant contributions to charge exchange scattering from surfaces in a relatively short time. This research effort should provide reliable values for some of the parameters used in current models, guidance as to the range of validity of certain models, and intuitive pictures for thinking about the atom-surface interaction.