强激光场中的中性原子及其加速研究

Research of interaction of itense laser filed and atoms is the basis to understand the interaction of strong laser with a variety of complex substances, and it is a cutting-edge scientific issuese having relation with major projects such as laser constraint fusion. Ionization processes of atoms in a strong laser field show a non-perturbative and nonlinear complex dynamical behavior. The rescattering of tunneling electrons with their parent nucleus driven by strong laser, had given rise to results in a high-energy threshold ionization spectroscopy, non-sequential ionization phenomena. Recently, it was found recapture of tunneling electrons in the rescattering processes and atoms acceleration phenomena, e.g., the survival of neutral rydberg atoms in a strong laser field and their acceleration. The project aims at the application of quantum theory and semi-classical trajectory simulation method, combined with the latest experimental progress, in-depth study of the process of rescattering electron and nucleus correlation effects, reveal the neutral atoms survival mechanism and the acceleration mechanism of neutral atoms, explore the rescattering process manipulation the atomic internal attosecond scale electron motion and structural changes in the feasible method. In-depth study of the relevant issues will help to understand the microscopic dynamics of matter in attosecond extreme light pulse, and orbital tomography as well as novel radiation sourceses.

强激光与原子相互作用研究是理解强激光与各种复杂物质相互作用的基础，是与激光约束聚变等重大工程相关的基础前沿科学问题，其研究具有很好的科学意义和应用背景。强激光场中原子的电离过程是非微扰、高度非线性的动力学行为。其中，隧穿电子在强场驱动下与母核发生再散射过程将导致高能的阈上电离能谱、非序列电离等现象。近年来，实验发现再散射的隧穿电离电子的再俘获和中性原子加速，也即强场中高里德堡态原子残存及其加速这种新物理现象。本项目将从量子理论出发，结合半经典轨道模拟方法，发展强激光与原子相互作用的理论模型，并关注最新实验进展，深入研究再散射过程中电子和母核的关联效应，揭示中性原子残存机理和中性原子加速机制，探索操控原子内部阿秒尺度的电子运动及结构变化的可行方法。这些问题的深入研究，将提升人们对强激光与物质相互作用微观动力学机理的认知水平，在阿秒脉冲产生、轨道层析成像以及新型辐射源等方面有潜在应用。

研究强激光场中原子的电离过程中的非微扰、高度非线性的动力学行为是一个具有理论挑战和实用价值的课题。本项目从量子理论出发，结合半经典轨道模拟方法，发展强激光与原子相互作用的理论模型，并关注最新实验进展，着重研究了原子分子的含时动力学问题。经过四年的研究，本项目取得的主要成果包括：一、强场与多电子原子相互作用的电子屏蔽和贯穿效应；二、隧穿电离光电子的低能结构；三、马约让纳星表示与大角动量态的几何相位；四、强场双电离的能谱标度率和关联电子超快热化，以及利用垂直双色光实现对电子关联的操控研究；五、环形高斯光束在大气中的传播和光成丝；六、三聚体在强场中的解离动力学；七、阿秒瞬态光吸收谱及其在电子运动超快探测中的应用；八、强激光场中正负电子对的产生问题；九、椭偏极化光场中的非绝热隧穿电离效应。