Development and application of time-dependent R-matrix theory for the multi-electron dynamics of atoms in ultra-short light pulses

超短光脉冲中原子多电子动力学瞬态 R 矩阵理论的发展和应用

• 批准号: EP/E000223/1
• 负责人: Hugo Willem Van Der Hart
• 金额: $ 39.61万
• 依托单位: Queen's University Belfast
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE000223%2F1
• 关键词: Development; application; time; dependent; matrix

We aim to develop the theory and associated computer programsto describe the time-dependent dynamics of a general atom in anultra-short, intense laser pulse. Current technology allows the creationof light pulses that are comparable in duration to the time it takesan electron to orbit an atom. By subjecting atoms to these shortpulses, it may be possible to adjust the electronic motion and henceto control the atom to an unprecedented degree.We aim to develop a theory that can be used to accurately predict theresponse of the entire multi-electron atom. To do so, we combinea multi-electron atomic theory, such as the R-matrix theory, withtime-dependent numerical techniques to obtain a novel approach for thedescription of atoms: the time-dependent R-matrix theory. We will developa substantial, new, computational program, containing several thousandsof lines of code, which exploits existing programs, developed by theapplicants, and which builds on our expertise in developing new programsas a world-leading group in theoretical atomic physics. This program willrequire significant computational resources, and the codes to be developedwill thus be developed for mid-range parallel computers.Initial investigations will be focussed on the noble-gas atoms from Neonwards, since these are the atoms most often used in state-of-the-artshort-pulse experiments. However, these atoms can only be studiedtheoretically with proper accuracy through explicit multi-electron techniques,such as the ones in the proposed method. By comparing results obtainedby the time-dependent R-matrix program with results obtained by thetime-independent R-matrix Floquet program, we will furthermore developunique insight into the detailed atomic dynamics in strong laser fields.Following the initial investigation of the behaviour of atoms in ultra-short pulses,we will continue the development of the codes towards the investigation ofprocesses in which two electrons are ejected. These processes will be ofincreasing interest in the coming years due to new free-electron laser facilities,which will provide high-intensity X-ray radiation. When atoms are subjected tosuch radiation, several electrons can be emitted simultaneously. The developmentof a computer code capable of describing double ionization of general atoms inintense light fields will thus provide a massive boost to all research exploiting thesenew X-ray radiation facilities.

我们的目标是发展理论和相关的计算机程序来描述一般原子在超短、强激光脉冲中的随时间动力学。目前的技术允许产生光脉冲，其持续时间与电子绕原子运行的时间相当。通过使原子受到这些短脉冲的影响，就有可能调节电子运动，从而将原子控制到前所未有的程度。我们的目标是发展一种理论，可以用来准确地预测整个多电子原子的响应。为此，我们将多电子原子理论，如r矩阵理论，与时间相关的数值技术相结合，以获得一种描述原子的新方法：时间相关的r矩阵理论。我们将开发大量新的计算程序，包含数千行代码，利用申请人开发的现有程序，并建立在我们作为理论原子物理领域世界领先团队开发新程序的专业知识基础上。这个程序将需要大量的计算资源，因此要开发的代码将为中档并行计算机开发。最初的研究将集中在来自Neonwards的稀有气体原子上，因为这些原子是最常用的最先进的短脉冲实验。然而，这些原子只能通过明确的多电子技术在理论上以适当的精度进行研究，例如所提出的方法中的技术。通过比较时变r矩阵程序与时变r矩阵Floquet程序的结果，我们将进一步深入了解强激光场中原子动力学的细节。在对原子在超短脉冲中的行为进行初步研究之后，我们将继续开发代码，以研究两个电子被射出的过程。由于新的自由电子激光设备将提供高强度的x射线辐射，这些过程将在未来几年受到越来越多的关注。当原子受到这种辐射时，可以同时发射几个电子。因此，能够描述一般原子在强光场中双重电离的计算机代码的开发将为利用这些新的x射线辐射设施的所有研究提供巨大的推动。