Time Resolved Electron Energy Loss Spectrometer

参考Siegbahn用于X射线光电子能谱的色散补偿原理，设计了EELS光谱仪。在这种情况下，(1)原则上，所有进入单色仪的电流都可以用于EELS测量；(2)通过能量高，因此，样品电流高。麻烦是异常和空间电荷。在180半球面光谱仪的情况下，焦点在180球体的边缘，并且为了定位样品，在单色仪的输出和样品之间以及样品和分析仪的输入之间需要不会丢失位置信息的透镜。在本研究中，谱仪采用90 - <s:1>扇形。通过对几种电子枪的设计，对其能量分辨率和透射率进行了优化。得到的能量分辨率为20 meV，对应的探测器电流为200pA。这些结果将为未来使用180 <s:1>球的时间分辨光谱仪的设计提供重要的信息。

An EELS spectrometer was designed by reffering to the dispersion compensation principle used by Siegbahn for X ray photoelectron spectroscopy. In this case, (1) in principle, all currents which enter the monochromater can be used for EELS measurements, and (2) pass energy is high, and thus, the sample current is high. Troubles are aberration and space charges. In the case of 180ﾟ semispherical spectrometer, the focus is at the egde of the 180ﾟ sphere and for the sample to be positioned, lenses which do not lose information on positions are needed between the output of the monochrometer and the sample and between the sample and the input of the analyzer. In this study, the 90ﾟ sector was used for the spectrometer. The optimization of the energy resolution and transmission was performed by the design of several electron guns. The obtained energy resolution was 20 meV,and the corresponding detector current was 200pA.These results are expected to give important informations on the future design of a time-resolved spectrometer by the use of 180ﾟ sphere.