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上安装了电子能量选择器和分析器。该光谱仪的入射能量可以从100 eV到500 eV变化，典型的能量分辨率约为80 meV(半高全宽=半高宽)。其次，我得到了一氧化氮(NO)的电子能量损失谱，并在动量转移范围K^2=0-0.8时测定了NO的价激发3Sσ(v‘=0-3)的广义振子强度。在这项实验中，我还使用了电子能量损失谱仪，另一方面，进行了碎片离子的动能测量，以获得分子、甲烷、氢、水和氨在电子碰撞下的解离电离动力学信息。特别是测定了甲烷裂解过程中质子的动能分布。A…更多的飞行时间(TOF)质谱仪和脉冲电子枪被用于这些实验。(并非巧合)。我可以通过使用离子电离和提取脉冲之间的时间定义的时间延迟来区分TOF光谱上的热离子和高能离子。在这段时间内，由于高能离子从电离区分散开来，除了沿着探测器方向移动的高能离子外，我无法检测到其他高能离子。然而，由于热离子的运动很少，所以所有的热离子都可以被探测到。然后考虑离子的收集效率，计算了碎片离子的动能分布。这些结果已经发表在论文中(见下一页)，我已经做了两次受邀的演讲。最后，我在我们的装置上安装了四极质谱仪。对于这种改装，其符合率应优于TOF光谱仪。目前，我正在调整仪器，希望在不久的将来能获得新的符合结果。较少

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