Visualization of short laser pulse ionization and dissociation processes

短激光脉冲电离和解离过程的可视化

• 批准号: 288215-2007
• 负责人: Witzel, Bernd
• 金额: $ 2.38万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=456555
• 关键词: Visualization; short; laser; pulse; ionization

Nearly all previous experimental studies on the intense-field induced dynamic response of atoms and molecules suffer from the fact that signals are collected from all over the focal volume, so that important input parameters of the experiment such as intensity, time profile and phase of the radiation field are not well-defined. Particularly in short laser pulse interaction, it cannot be excluded that the distribution of the intensity of a laser focus is influenced by a complicate dependency of spatial time/pulse/laser-frequency distributions in the focus region due to a distortion of the laser wavefront or the influence of dispersive optical elements. This general problem can be solved with a new generation of time-of-flight mass spectrometer which offers the ability to record the ion yield of a well defined volume outside of the focus regime, where the laser intensity is nearly constant. This will allow us to measure the ion yield and the intensity distribution at focus as well as the pulse length/intensity/wavelength dependence form short pulse laser ionization processes. Secondly, we want to use an electron - imaging spectrometer to understand a possible influence of Rydberg states on the ionization process. The measurement of the wavelength dependency will be completed with the search for non-linear inner shell ionization processes in atoms.

以往关于强场诱导原子分子动态响应的实验研究几乎都存在这样一个问题，即信号是从整个焦区采集的，因此实验的重要输入参数，如辐射场的强度、时间分布和相位等都没有得到很好的定义。特别是在短激光脉冲相互作用中，由于激光波前的变形或色散光学元件的影响，不能排除激光焦点的强度分布受到焦点区域中空间时间/脉冲/激光频率分布的复杂依赖关系的影响。这一普遍问题可以用新一代飞行时间质谱仪来解决，它提供了在聚焦区域之外记录定义良好的体积的离子产额的能力，在聚焦区域中，激光强度几乎是恒定的。这将使我们能够测量离子产额和聚焦强度分布，以及短脉冲激光电离过程中脉冲长度/强度/波长的依赖关系。其次，我们想用电子成像光谱仪来了解里德堡态对电离过程的可能影响。波长依赖性的测量将通过寻找原子中的非线性内壳层电离过程来完成。