410～373nm激光作用下四甲基硅的多光子电离与解离

Multiphoton Ionization and Dissociation of Tetramethylsilane at 410～373 nm Laser Radiation

利用平行板电极装置测定了四甲基硅于某些波长点处的激光光强指数，讨论了多光子电离（ＭＰＩ）谱中某些话线的归属。通过对飞行时间（ＴＯＦ）质谱峰宽的分析并结合质谱实验结果，讨论了该分子可能的ＭＰＩ过程，得到了较高能量下Ｓｉ＋的产生仍以中性碎片的解离──硅原子的电离为主，而Ｓｉ＝（ｎ＝１～３）的形成则以中性碎片的自电离为主的结论。

In this peper, the laser power dependence measurement of Si(CH3)4 with parallel plate ionization cell at some wavelengths was reported and the assignment of some transitions in multiphoton ionization(MPI) spectra was discussed. By analysing the pekwidths of time-of-flight (TOF) mass spectra and other experimental results, the possible MPI process of Si(CH3)4 has been studied. It concluded that Si+ mainly came from silicon ionization after neutral molecular fragmentation at higher energy laser radiation, whereas (n=1 ～3) mainly came from auto-ionization of neutral molecular frasments.