Dissociative Ionization Dynamics of Molecules via Excited state by Optical Forbidden Transitions

首先，在我们的飞行时间质谱仪中安装了电子能量选择器和分析器。谱仪的撞击能量可以从100到500 eV变化，并且典型的能量分辨率为约80 meV（半峰全宽=FWHM）。第二，获得了NO分子的电子能量损失谱，并在动量转移范围K^2=0-0.8内确定了NO分子价态激发3sσ（v ′ = 0-3）的广义振子强度。在本实验中，使用了电子通信大学激光科学研究所的电子能量损失谱仪，通过碎片离子的动能测量，获得了甲烷、氢、水、氨等分子的电子碰撞解离电离动力学信息。特别地，测定了甲烷裂解产生的质子的动能分布。一 ...更多信息 具有脉冲电子枪的飞行时间（TOF）质谱仪用于这些实验。(Not巧合）。我可以通过使用由离子电离和提取脉冲应用之间的时间定义的时滞来区分TOF光谱上的热离子和高能离子。在这段时间里，由于高能离子从电离区分散开来，我不能探测到高能离子，除了那些向探测器方向移动的离子。然而，由于热离子几乎不移动，所以可以检测到所有的热离子。在考虑离子收集效率的情况下，计算了碎片离子的动能分布。这些结果已经作为论文发表了（见下一页），我还应邀做了两次演讲，最后，我把四极质谱仪安装在我们的装置上。对于这种改进，符合率应优于飞行时间谱仪。目前，我正在对装置进行调整，希望在不久的将来能得到新的符合结果。少

First of all, the energy selector and analyzer for electrons had been installed in our Time of Flight Mass Spectrometer. The impact energy of the spectrometer can be varied from 100 to 500 eV, and the typically energy resolution is about 80 meV (full width at half maximum=FWHM). Secondly, I had obtained the electron energy-loss spectra for nitric oxide (NO), and the generalized oscillator strengths for valence excitation 3sσ(v'=0-3) of NO had been determined in the momentum transfer range K^2=0-0.8. For this experiments, I had also used the electron energy-loss spectrometer at the Institute for Laser Science in the University of Electro-Communications.On the other hand, the kinetic energy measurements of fragment ions had been carried out to obtain the information of the dissociative ionization dynamics of molecules, methane, hydrogen, water, and ammonia by electron impact. In particular, the kinetic energy distributions for proton by the fragmentation of methane had been determined. A … More time-of-flight (TOF) mass spectrometer with a pulsed electron gun had used for these experiments. (Not coincidence). I can distinguish between thermal and energetic ions on a TOF spectrum by using the time-lag defined by the time between the ionization of the ions and application of the extracting pulse. During this time-lag, since the energetic ions are dispersed from the ionization region, I can't detect the energetic ions except ones that move in the direction of the detector. However, since the thermal ions move little, all of thermal ions can be detected. Then the kinetic energy distributions of fragment ions are calculated with considering the collection efficiency of ions. These results have been already published as the paper (see next page), and I had given two invited talks.Finally, I had installed the quadrupole mass spectrometer in our apparatus. For this modification, the coincidence rate should be better than that by TOF spectrometer. At present, I adjust the apparatus, and I hope that the new coincidence results will be obtained in the near future. Less