Focusing properties of a mirror analyzer with hexapole cylindrical field

In this work, motion of charged particles is studied in a new-type electrostatic field—the multiple cylindrical one, formed by superposition of electrostatic fields of a cylindrical mirror and a circular hexapole. On a base of the power-series analytical technique of solution of the equation of motion presented in integro-differential form, charged particle trajectories are calculated. Data on focusing properties of hexapole cylindrical mirror analyzer are obtained.     

Photoelectron branching ratios with a cylindrical mirror energy analyzer

A cylindrical mirror photoelectron energy analyzer suitable for measuring photoelectron branching ratios is described. The analyzer incorporates a pre-retarding/ accelerating system. This configuration is shown to have advantages over a conventional mirror analyzer in reduced pressure-sensitive scattering effects which can effect the accuracy of the branching ratios, and in increased sensitivity to low energy electrons. The electron collecting efficiency of the analyzer for a number of operating modes is given.     

Design of a cylindrical mirror analyzer for use with synchrotron radiation to investigate autoionization phenomena and angular distributions of photoemitted electrons

A first-order cylindrical mirror analyzer was designed and constructed to take advantage of the continuum nature and polarization of synchrotron radiation to study autoionization and angular distributions of electrons. Autoionization in the region 14.20–16.35 eV was found to contribute intensity to the lowest ionic state of ethylene. Seven Rydberg series converging to the seven vibrational levels of the fourth ionic state are reported. The applicability for measuring gas-phase angular distributions and the expected intensity variations from this type of experiment are discussed.     

Charged particle energy analyzer based on a modified cylindrical mirror

A modified design of an electrostatic energy analyzer of the cylindrical mirror type is suggested. The outer electrode of the modified analyzer consists of three cylinders with equal radii and different potentials. The electron-optical properties of the analyzer are numerically simulated, and it is demonstrated that it may offer a much higher focusing quality than a conventional cylindrical mirror. Optimal design and operating conditions are found for which the spherical aberration decreases fivefold compared with the conventional mirror.     

Photoelectron and Penning ionization electron spectrometry with a differential retarding field analyzer

A differential retarding field analyzer of the type described by Lindau et al.² has been tested in detail by photoelectron spectrometry in the 0–10-eV range. A resolution of 17 meV was obtained together with a satisfactory line-shape and sensitivity. The important potential parameters concerning resolution and line-shape, and the energy-dependence of the transmission of the analyzer have been determined experimentally. As a first application, Penning ionization electron spectra for the systems He(2³S)-N₂ O₂, and HCl have been obtained with the transmission-calibrated analyzer.     

Collecting efficiency of a cylindrical mirror electron energy analyzer with pre-retarding lens

The electron collecting efficiency of a cylindrical mirror energy analyzer incorporating retardation of the electrons prior to analysis has been determined over the range 0 to 30 eV by two methods. The first method requires the use of a vacuum ultraviolet monochromator to produce monoenergetic electrons of different energies; the second method involves measuring the energy-brightness relationship of the retarding optics and should be applicable to any deflection analyzer with pre-retarding optics. The results of the two methods are compared and the limitations of the latter method are discussed.     

可控聚焦型减速场能量分析器的设计分析

基于之前减速电场能量分析的设计与实验,针对实验中出现的绝缘性不好、能量分辨率不高等问题,对原结构进行了改进与仿真分析,以更好地实现行波管电子枪电子注及注波互作用后电子注参数的精确测量和分析,为行波管的设计、性能改进和研制提供参考。该可控聚焦型减速场能量分析器结构将高压圆筒与减速栅网进行电气绝缘隔离,并在二者之间设置一个可控的小电压,产生的第二个静电透镜对发散的电子注产生加速会聚的作用,以削弱在第一个透镜聚焦作用的薄弱区域空间电荷效应及电子注发射角等因素对注发散的影响,调整粒子轨迹倾斜度和分辨率。同时,整体结构在不影响测试精度的情况下向小型化和轻型化发展。应用CST粒子工作室对不同粒子界面处粒子分布及整体场结构进行模拟,然后用Matlab软件进行数据处理并导出关键参数。着重分析结构性能的优化和提升在分辨率及半峰值全宽度等参数上的体现。结果表明该能量分析器适用于几keV到10keV的强流电子注的测量。     

可控聚焦型减速场能量分析器的设计分析

基于之前减速电场能量分析的设计与实验,针对实验中出现的绝缘性不好、能量分辨率不高等问题,对原结构进行了改进与仿真分析,以更好地实现行波管电子枪电子注及注波互作用后电子注参数的精确测量和分析,为行波管的设计、性能改进和研制提供参考。该可控聚焦型减速场能量分析器结构将高压圆筒与减速栅网进行电气绝缘隔离,并在二者之间设置一个可控的小电压,产生的第二个静电透镜对发散的电子注产生加速会聚的作用,以削弱在第一个透镜聚焦作用的薄弱区域空间电荷效应及电子注发射角等因素对注发散的影响,调整粒子轨迹倾斜度和分辨率。同时,整体结构在不影响测试精度的情况下向小型化和轻型化发展。应用CST粒子工作室对不同粒子界面处粒子分布及整体场结构进行模拟,然后用Matlab软件进行数据处理并导出关键参数。着重分析结构性能的优化和提升在分辨率及半峰值全宽度等参数上的体现。结果表明该能量分析器适用于几keV到10 keV的强流电子注的测量。     

Charged particle energy analyzer based on a modified cylindrical mirror in the ring-axis focusing mode

The electron-optical properties of systems with a modified structure of the energy analyzer in the form of a cylindrical mirror proposed earlier are investigated. The analyzer operating mode in which the source of charged particles is in the inner cylinder and the detector is on the cylinder axis (ring-axis focusing) is considered. It is shown using numerical simulation that the modified structure ensures higher focusing quality as compared to the traditional cylindrical mirror. The optimal structure and voltage supply are determined for which spherical aberration is five times smaller than with a conventional cylindrical mirror.     

Combined ESCA/Auger system based on the double pass cylindrical mirror analyzer.

In comparison with other ESCA apparatus, the presently described instrument offers several unique advantages. First, it is possible to accomplish high     

Effects of the working conditions of retarding field spectrometers on the energy distribution of secondary electrons

Retarding field spectrometers designed for Auger electron spectroscopy show spurious peaks in the low energy range which are connected with secondary electron emission from the electrodes of the spectrometer. We present a general explanation for all the spurious effects reported to date.The understanding of these phenomena has led us to the building of a new spectrometer which works with optimal experimental conditions.We present the results and experimental curves of secondary electron energy distribution for an evaporated aluminium target.     

Electromagnetic wave generation in a cylindrical resonator by electrons orbiting in a radial electrostatic field

The mechanisms leading to the generation of microwaves by electrons orbiting in a radial electrostatic field produced by a positively charged filament on the axis of a cylindrical resonator are investigated theoretically. The dispersion relations describing the interaction of the waves with the electrons are obtained. It is shown that the generation of electromagnetic fields is possible on account of both Cherenkov and plasma resonances. The frequencies and growth rates of waves under Cherenkov resonance conditions and also plasma resonance conditions in uniform and nonuniform electron layers are found. The advantages and disadvantages of different generation mechanisms are determined. Zh. Tekh. Fiz. 68, 91–94 (August 1998)     

Orientation dependence of oxygen adsorption on a cylindrical GaAs sample: II. Photoemission measurements

The orientation dependence of oxygen adsorption has been investigated by XPS and UPS on the surface of a cylindrically shaped GaAs single crystal with [11̄0] as its axis. This sample exposes the main low-index orientations (001), (111)Ga, (110), (111̄)As, etc. and all intermediate orientations. It was prepared by ion bombardment and annealing [see part I, Surface Sci. 120 (1982) 67). XPS was used to separate the known two forms of adsorbed oxygen quantitatively. The less tightly chemisorbed a-oxygen has an O 1s binding energy 1.50 ± 0.05 eV larger than the β-oxygen for all surface orientations. Comparison with UPS shows that for hv =40.8 eV the excitation probability of the O 2p orbitals for α-oxygen is four times larger than for β-oxygen. The Ga 3d peak shows the known chemical shift of 1.1 ± 0.1 eV induced by β-oxygen whereas α-oxygen causes no Ga 3d shift. Most of the α-oxygen desorbs thermally starting near room temperature, only a portion smaller than 20% is converted to β-oxygen; β-oxygen desorbs starting at 300–350°C slightly depending on orientation. These results confirm the interpretation of β-oxygen as dissociated oxygen. However, the nature of α-oxygen still is not clear. The strong orientation dependence of the total amount of oxygen is consistent with the Auger results published recently (see part I). The nature of α- and β-oxygen is found to be the same for all orientations. Also the ratio of adsorbed α- to β-oxygen depends surprisingly weakly on the orientation and on the exposure varying only between 0.35 and 0.7 as the extreme values. This suggests that the adsorption of α- and β-oxygen is connected. A possible model is that adsorption, probably of β-oxygen, starts from edges or other energetically less favourable sites and that this disturbance creates stresses or defects which serve as adsorption site for the α-oxygen.     

Orientation dependence of oxygen adsorption on a cylindrical GaAs sample: I. Auger measurements

The orientation dependence of oxygen adsorption has been investigated by AES on the surface of a cylindrically shaped GaAs single crystal with [111̄0] being its axis. It thus exposes the main low index orientations (001), (111)Ga, (110), and (111̄)As, as well as all their vicinal surfaces and intermediate orientations on its surface. It is shown that it is possible to prepare all these orientations simultaneously and with reasonable quality by ion bombardment and annealing (IBA). The orientation dependence of the amount of adsorbed oxygen in the range (001)(111)Ga(110)(111̄)As can be understood in terms of different sticking coefficients on the different types of terrace site and of enhanced adsorption on edge-adjacent sites. These edge-adjacent sites show saturation at about 4 × 10⁵ L. Starting from (110) towards (111)Ga, at first, steps one atomic layer high are found, changing to a height of two layers when approaching (331). This behaviour can be understood in terms of the known relaxation on (110). A deep minimum in the amount of adsorbed oxygen between (111̄)As and (001̄) is interpreted to be due to an As stabilized low sticking coefficient phase between (112̄) and (113̄). Early saturation (at～10⁵ L) on (001) and (111̄)As is consistent with the fact that these surfaces usually do not reach their room temperature equilibrium phase upon preparation by IBA. Sudden and accidental oxygen induced composition changes towards As-richer substrate compositions further confirm this.     

A coaxial open cavity resonator formed by a barrel-shaped outer mirror and a cylindrical inner mirror

A theoretical calculation of the principal parameter in an open coaxial cavity resonator formed by a barrel-shaped outer mirror and a cylindrical inner mirror was carried out. Analytic expressions were derived for the natural frequencies, the positions of the caustics, the field distributions and the ratios of the values of Q for various oscillation mode for 2d/ 1 ( is the wavelength; d is the characteristic dimension of the cavity). The results of numerical calculations allow the geometry of the cavity to be chosen for practical application.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 15, No. 1, pp. 117–125, January, 1972.     

A design for a cylindrical mirror analyser for use in auger spectroscopy

The design of a cylindrical mirror analyser for use in Auger spectroscopy is discussed. The main feature of the design is the use of hemicylinders in place of the usual full cylinders. Although there is a consequent loss in solid angle of collection the loss is offset by a relaxation in machining tolerances, greater access to the specimen, and a simpler method of construction. An analyser built to this design has been operated and found to have a resolution of 0.35% for a semiangular aperture of ± 6°. The limitation on resolution appears to be set by the size of the incident electron beam on the target.Auger and loss spectra obtained with the analyser are shown and compared with those for the same material obtained with a conventional retarding-field analyser.     

超光滑硅柱面反射镜的加工和检测

介绍了超光滑硅柱面反射镜的加工过程、工艺控制及检测方法。给出了由超光滑硅柱面反射镜组成的准直扩束系统的出射波面的检测结果。     

电子在圆柱形直流磁控管中的运动轨迹

分析了在电子直流磁控管中运动的规律,其轨道方程的积分形式得不出解析解,用计算机进行了数值求解,所得图象十分清晰。