【作者】 史岩；

【导师】 金明星；

【作者基本信息】 吉林大学 ， 原子与分子物理， 2010， 硕士

【摘要】 本篇论文主要通过介绍速度成像方法的基本原理和相关理论知识逐层深入的介绍了这一方法在理论和应用中涉及到的内容,同时还介绍了作者参与的CH2I2分子速度成像实验过程。离子速度成像实验是研究激光与分子相互作用的重要手段,而激光与分子相互作用的研究对基元反应有着重要意义,因此速度成像实验就成为了很多人关心的一种实验方法。本文前半部分着重阐述了激光与分子相互作用的意义和发展前景,并对相关的基本问题做了一定程度的说明。然后介绍了速度成像的相关基础知识(如飞行时间质谱、离子透镜、反Abel变化等)和相关实验设备,以及作者所在的小组是如何使用这些设备的,并对CH2I2实验中遇到的一些具体问题做出了分析。通过对CH2I2分子的速度成像实验得到的结果进行分析。我们认,用波长为800nm,光强为1890μJ的垂直偏振光作用在CH2I2分子上,产生一个多光子电离过程,Ⅰ+分为高能和低能两个部分,低能部分是CH2I2+吸收2个光子能量解离出CH2I和I+得到的,而低能部分是库伦爆炸的产物；CH2I+则是由CH2I2+吸收1个光子得到的。无论是从角度分布还是从能量的计算这一结论都与理论计算的结果相差不大,从而也证明了我们的推断。最后对我们的研究作出了展望,未来将在现有的系统上添加六极杆尝试实现态选择。更多还原

【Abstract】 The recent progress of laser technology has reached a burst of femtosecond science where the photodissociation dynamics of molecules plays an important role in physics. In particular, the recent advancement ofintense laser field has led to a set of strong-field phenomena, such asmultiphoton ionization, multiphoton resonance, high-order harmonic generation, etc, are all beyond the perturbative regime. The main approachis the ion velocity imaging technique. This technique is formed a set of completely experimental techniques and theoretical models, which provided a solid guarantee for our study of molecular photon dissociation process.This thesis introduces the basic principle of velocity imaging method and the experimental equipments, and makes an explicit explanation of them by the velocity imaging experiment of CH2I2.Meanwhile, we analyses the evolution of energy structure of CH2I2 in 800 nm laser pulse by experiment. The main achievements are summarized below: The first part is the introduction of photon dissociation dynamics theory and the development and improvement in the future. We simply described the velocity imaging techniques, and made the derivation of some basic problems in photon dissociation dynamics.The second part is the explicit description of velocity imaging techniques. We simply described the velocity imaging techniques, and made the derivation of some basic problems in photon dissociation dynamics. The important process of ion velocity imaging techniques consist of time-of-flight mass spectrometry (TOFMS), ion lens, A-type antiferromagnetic model.The third part is the introduction of experimental devices, and an explicit explanation for the problem which we always met in the debugging and checking process. In actually experimental process, we always met various problems in experiment although we know the theoretical process, so it is necessary for us to familiar with instrument and equipment in experiment.The fourth part is the analysis for the experimental results of the velocity imaging of CH2I2 molecule. We can make a conclusion that the 800 nm,1890μJ vertical polarized laser pulse act on CH2I2 molecule can produce a multiphoton ionization process. The ionization energy of ion from experimental is almost the same as the theoretical calculation, which also proved our deduction.更多还原