Excitation and Ionization in Atomic Collision Processes -- General Theory and Accurate Numerical Calculations

该项目研究光（主要是激光）和带电粒子（主要是电子）与原子，离子和小分子的相互作用。 这些结果对于理解基本碰撞动力学具有重要意义，它们也满足了对精确原子数据的迫切实际需求，以模拟恒星，等离子体，激光和行星大气的物理。 该项目的短脉冲强激光部分涉及数值时空网格上的时间相关薛定谔方程的精确解。 随着计算资源的快速发展，这种对现实而不是理想化模型系统的研究只是在最近几年才成为可能。 这项工作对于成像和最终控制亚微观反应的进一步发展非常重要，预计将通过从物理学到化学并最终生物学产生广泛的影响。 本项目支持世界范围内的许多实验工作，并将培训一名博士后助理和一些研究生，使他们对问题有基本的理解，并使用高度复杂的数值技术。大部分数值计算将基于非微扰R矩阵（紧耦合）方法，以及直接解决方案的含时薛定谔方程使用各种基于网格的方法和基函数的扩展。 对于通过强阿托/飞秒激光脉冲对复杂原子进行单电离和双电离，这些方法将以这样一种方式结合起来，即可以以高效和优化的方式处理“大问题”的各个部分。 这一策略将被扩展到双电离涉及内壳层以及双原子分子的治疗。 特别令人感兴趣的将是极具挑战性的，但最终必须同时处理核和电子运动。 有重大的困难与制定的问题和随后的数值处理。 重点将放在数值方法的测试和结果的可视化上，这两者都是学生参与的理想选择。

The project studies the interaction of light (mostly lasers) and charged particles (mostly electrons) with atoms, ions, and small molecules. The results are of importance for the understanding of the fundamental collision dynamics, and they also fulfill the urgent practical need for accurate atomic data to model the physics of stars, plasmas, lasers, and planetary atmospheres. The short-pulse intense-laser part of the project deals with accurate solutions of the time-dependent Schroedinger equation on a numerical space-time grid. With the rapid advances currently seen in computational resources, such studies for realistic rather than idealized model systems have only become possible in recent years. This work is important for further developments in imaging and ultimately controlling of submicroscopic reactions, which is expected to have broad impact by reaching out from physics to chemistry and ultimately biology. Many experimental efforts worldwide are supported through the present project, which will also train a post-doctoral associate and a number of research students in the basic understanding of the problem and the use of highly sophisticated numerical techniques.Most of the numerical calculations will be based upon the non-perturbative R-matrix (close-coupling) method, as well as direct solutions of the time-dependent Schroedinger equation using various grid-based approaches and basis-function expansions. For single and double ionization of complex atoms by intense atto/femto-second laser pulses, the methods will be combined in such a way that individual parts of the "big problem" can be treated in highly efficient and optimized ways. This strategy will be extended to the treatment of double ionization involving inner shells as well as diatomic molecules. Of particular interest will be the highly challenging, but ultimately necessary simultaneous treatment of the nuclear and electronic motion. There are major difficulties associated with both the formulation of the problem and the subsequent numerical treatment. Much emphasis will be placed on the testing of numerical methods and the visualization of the results, both of which are ideal for student involvement.