Electronic Structures of Metallic Cerium Compounds Studied By Photoelectron Spectroscopy and Bremsstrahlung Isochromat Spectroscopy

为了获得金属铈化合物在费米能级以下的电子结构信息，已经计划建造一个组合光谱仪。该仪器由光电子能谱仪（PES）和轫致致等色能谱仪（BIS）组成。该装置的PES已完成并运行良好。在这段时间里，它是设计和建设国际清算银行。这包括用于AlK α辐射的单色仪和用于激发的电子枪系统。首先，设计了单色仪，其中石英片用于样品辐射的单色。为了尽可能多地收集辐射，设计了一种多弯石英晶体。弯曲石英晶体的半径为400mm。构建了晶体位置调整系统；用于样本的运动和倾斜。接下来，我们设计了一支电子枪。为了确定电子的运动轨迹，研究开发了电子运动轨迹计算的计算机程序。在光线追踪的基础上，确定了适合于BIS的透镜系统。电子透镜的最终设计由电子发射枪的一部分和电子束聚焦和电子加速的三圆柱电极透镜组成。电子枪系统的规格如下：(1)电子的加速电压可以在10 ~ 1500 eV之间变化，(2)样品上的焦点光斑尺寸小于2 mm phi，(3)可以尽可能地获得电子束电流。第三种规格的实现是非常困难的，因为要获得高光束电流，发射源必须加热得太高。然后，由于远光束的作用，包括电子枪在内的腔室的真空度变差。考虑这一困境对电子枪的设计是很重要的；光束电流达到极限。电子枪和石英单色仪将在真空小于1 × 10^<-10> Torr的腔室中组装，组合光谱仪计划完成，用于测量与4f电子有关的物质的占据带和空带中的态密度。少

The construction of a combined spectrometer has been planned in order to obtain the information about the electronic structures just below the Fermi level for metallic cerium compounds. This apparatus consists of a photoelectron spectrometer (PES) and a bremsstrahlung isochromat spectrometer (BIS). Of this apparatus the PES has been completed and has been well operated. In this time it is to design and construct the BIS. This consists of the monochromator for AlK alpha radiation and the electron gun system for excitation. Firstly, the monochromator has been designed, in which some quartz plates are used for monochromatization of radiation from samples. In order to collect the radiation as much as possible, a multi-bent quartz crystals has been designed. A radius of the bent quartz crystal is 400 mm. The system of adjustment for position of the crystals has been constructed ; for the movement and inclination of the samples.Next, we have designed an electron gun. For the determination of … More the design, the computer program for calculating an electron trajectory has been researched and developed. Based on the ray-tracing, a lens system has been so determined as to be suitable for BIS. The final design of the electron lens consists of a part of electron emission gun and three-cylindrical electrode lens for focusing electron beam and acceleration of electrons. The specification of the electron gun system is as follows ; (1) Acceleration of voltage for electron can be varied from 10 to 1,500 eV, (2) The focal spot size on sample is less than 2 mm phi , and (3) The current of electron beam can be obtained as much as possible. It is very difficult to realize the third specification, because the emission source must be warmed too high for obtaining the high beam current. Then, the vacuum of the chamber including the electron gun grows worse because of the high beam. The consideration for this dilemma is important for designing the electron gun ; The limit of the beam current occurred.The electron gun and quartz monochromator are to be assembled in the chamber having a vacuum of less than of 1 x 10^<-10> Torr, and the combined spectrometer is scheduled to be complete for measuring the density of states in the occupied and empty bands of the materials concerning to 4f electrons. Less