共振效应对V型分子及其二聚体在强场中解离动力学的影响

Resonance can change the molecular structure and affect the dynamics of dissociation，it plays an important role in the ionization and dissociation of molecules and dimers. It is an urgent problem to determine the effect of resonance on the dissociation dynamics of molecules and dimers in strong laser fields. The structures of molecules and dimers in different resonance states can be imaged by coulomb explosion and pump-probe technology，the evolution of dissociated fragments of molecules and dimers can be monitored in real time, furthermore, the information of structure and dissociation dynamics of molecules and dimers can be obtained. In this project, we will combine the femtosecond laser field and the COLD Target Recoil-Ion Momentum Spectroscopy (COLTRIMS) to realize the high-precision measurement of electron-ion coincidence velocity imaging. We will obtain the momentum of fragments generated by molecules and dimers under resonance and non-resonance conditions, respectively; reconstruct the information including the angle and bond length of the ions; and determine the influence of resonance effect on their structure. In combination with the femtosecond laser resonance pump-probe method, the evolution of the excited state will be obtained, and the influence of resonance effect on the dissociation dynamics process will be further explored, the ultrafast femtosecond dissociation dynamics and the measurement of structural evolution of molecules and dimers will be realized, it provides a physical basis for the real-time measurement and research of molecular ultrafast structural evolution.

共振会改变分子构型并影响解离动力学，在分子和二聚体的电离和解离过程中起着至关重要的作用，确定共振效应对分子和二聚体在强场中的解离动力学的影响是亟待解决的问题。结合库仑爆炸以及泵浦探测技术可以实现分子和二聚体在不同共振态下的结构成像，并实时监测分子和二聚体结构随时间的演化规律，进而实现分子和二聚体的结构演化及解离动力学信息的获取。本项目将结合飞秒激光和冷靶反冲离子动量成像谱仪，利用电子-离子多粒子符合速度成像高精度测量，分别获取分子和二聚体在有共振及无共振条件下产生碎片的动量，重构离子夹角和键长信息，研究共振效应对其构型的影响。结合飞秒激光共振泵浦探测方法探究激发态演化规律，深入探究共振效应对其解离动力学的影响，实现分子及其二聚体的超快飞秒解离动力学的研究以及结构演化的测量，为分子超快结构演化的实时测量和研究提供物理基础。

超快强激光场与原子分子相互作用是近年来原子与分子物理领域备受关注的研究方向之一,电离和解离是产生诸多强场物理过程的基础。强场中的激发态共振会影响分子和二聚体的电离和解离过程，确定共振效应对分子和二聚体解离动力学的影响是一个具有挑战性的研究课题。本项目通过电子-离子符合成像测量，结合库仑爆炸以及泵浦探测技术，实现了多体通道的提取，研究了分子和二聚体的强场电离激发态共振、分子构型变化及核振动波包演化动力学。主要对V型分子二氧化氮及其二聚体开展了研究，发现共振激发使不同波长条件下的电子态选择性居布不同，导致部分库仑爆炸通道对应的能谱有很大差异，二体库仑爆炸通道存在通道切换效应和通道竞争的机制。分析键长和键角的变化关系，得出共振效应更容易使分子向小角度演化，确定了共振效应对二聚体电离率和构型的影响。实现了时间分辨下的超快解离动力学过程的探测和操控，重构了反应动力学过程。项目研究有助于提升对分子与超快强激光相互作用的认识，对分子强场物理理论发展起到积极的推动作用，为超快结构演化的实时测量和研究提供基础。