Photon- and Electron-Driven Atomic Collision Processes: General Theory and Accurate Numerical Calculations

该项目涉及光（主要是激光）和带电粒子（主要是电子）与原子和离子的相互作用。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需要在数值时空网格上精确求解含时薛定谔方程。随着计算资源的快速发展，这种研究现在可以针对现实而不是理想化的模型系统进行。这项工作对于促进亚微观反应的成像和控制的进一步发展非常重要，而这反过来又有望通过从物理学到化学并最终到生物学产生广泛的影响。另一个主题是电子-原子碰撞中产生的量子纠缠。 这一领域在量子信息技术中具有应用潜力。 本项目将为世界范围内的许多实验工作提供支持，并将培养一名博士后助理和一批研究生。大部分数值计算将基于非微扰R矩阵（紧耦合）方法使用具有非正交轨道集的高度灵活的B样条实现，以及直接解决方案的时间依赖薛定谔方程使用各种网格为基础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。一个例子是使用时间无关的多电子库仑和偶极矩阵元素的B样条R-矩阵方法在传播计划的时间相关的薛定谔方程在几个周期的激光脉冲的解决方案。 这个一般策略将被扩展到涉及内壳层的双电离的治疗。 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。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

This project deals with the interaction of light (mostly lasers) and charged particles (mostly electrons) with atoms and ions. The results are of importance for the understanding of 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 requires 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 can now be conducted for realistic, as opposed to idealized, model systems. This work is important to facilitate further developments in the imaging and control of submicroscopic reactions, which in turn are expected to have broad impact by reaching out from physics to chemistry and ultimately biology. Another topic is quantum entanglement created in electron-atom collisions. This area has potential for applications in quantum information technology. Many experimental efforts worldwide are supported through the present project, which will also train a post-doctoral associate and a number of research students.Most of the numerical calculations will be based upon the non-perturbative R-matrix (close-coupling) method using a highly flexible B-spline implementation with non-orthogonal orbital sets, 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. One example is the use of time-independent multi-electron Coulomb and dipole matrix elements from the B-spline R-matrix method in a propagation scheme for the solution of the time-dependent Schroedinger equation in a few-cycle laser pulse. This general strategy will be extended to the treatment of double ionization involving inner shells. 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.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.