Studies on Electrode Surface Conditions and Vacuum Breakdown Phenomena by an Electron Emission Microscope

电子发射显微镜研究电极表面状况和真空击穿现象

• 批准号: 09650309
• 负责人: KOBAYASHI Shinichi
• 金额: $ 2.18万
• 依托单位: Saitama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650309/
• 关键词: Field Electron Emission; Electron Emission Microscope; Electrical Breakdown in Vacuum; Vacuum Microelectronics; Vacuum Electron Sources; 真空マイクロエレクロトニクス

The aim of this project is to find changes of the aspect of electron emission sites on electrodes of a vacuum gap by using an electron emission microscope developed by our laboratory. The electron emission microscope developed has the feature that imaging of electron emission sights on not only a point electrode but also a broad area electrode is possible.In 1997, the first year of the research term, followings were clarified.1. The images of electron emission sites were obtained and operating performance of the electron emission microscope was confirmed.2. It was observed that field electron emission sites vibrated. This may be due to moving of emission sites. To confirm moving of emission sites it is necessary to make further experiments.3. Field electron emission sites on broad area oxygen-free copper electrodes of a vacuum gap were observed by this microscope.The observations revealed that macroscopicaly single emission site consists of several sites.In 1998, the last year of this project, observations of electrodes of vacuum gaps were carried in succession, and the results were summarized as follows.1. The magnification factor of the microscope was calibrated by photoelectron emission images of 50 mu m diameter Al wire excited by ultra-violet light.2. Observations of oxygen-free copper electrodes of vacuum gaps clarified that a macroscopically single field electron emission site consists of several sites.3. In addition, observations of pit-free electropolished aluminum electrodes revealed that the aspect of electron emission sites changed significantly before and after breakdowns.By this research it becomes possible to clarify changes of aspect of electron emission sites. The instrument will provide a powerful means to asses electrode surface treatments to obtain higher voltage hold-off capability of a vacuum gap.

本项目的目的是利用本实验室研制的电子发射显微镜，观察真空间隙电极上电子发射位点的变化。所研制的电子发射显微镜具有既可以在点电极上成像又可以在大面积电极上成像的特点。在1997年，研究期的第一年，澄清了以下几点：获得了电子发射部位的图像，并对电子发射显微镜的工作性能进行了验证。观察到场电子发射位点发生了振动。这可能是由于排放地点的移动。为了确认排放点的移动，有必要做进一步的实验。用该显微镜观察了真空间隙大面积无氧铜电极上的场电子发射位点。观测结果表明，宏观上单个发射点由多个发射点组成。1998年，也就是本项目的最后一年，连续进行了真空间隙电极的观测，结果总结如下：利用直径50 μ m的铝丝在紫外光激发下的光电子发射图像，标定了显微镜的放大倍率。对真空间隙无氧铜电极的观察表明，宏观上单场电子发射位点由多个位点组成。此外，对无坑电抛光铝电极的观察表明，击穿前后电子发射位点方面发生了显著变化。通过这一研究，阐明电子发射位方面的变化成为可能。该仪器将提供一个强大的手段，以评估电极表面处理，以获得更高的电压保持能力的真空间隙。

项目成果

K.Shirai: "Fabrication of Field Electron Microscope and Observation of Electron Emission Sites(in Japanese)" 1998 National Convention Record of the Institution of Electrical Engineers of Japan. Vol.1. 201 (1998)

K.Shirai：“现场电子显微镜的制造和电子发射位点的观察（日文）”1998年日本电气工程师学会全国大会记录。

S.Kobayashi: "Electron emission microscope for use in electron emission sites observations" Applied Surface Science. 印刷中. (1999)

S.Kobayashi：“用于电子发射位点观察的电子发射显微镜”，出版中的《应用表面科学》。

白井賢治: "透明陽極及び放射型電子顕微鏡を用いた電子放出点の観測" 電気学会放電研究会資料. ED-98-204. 31-31 (1998)

Kenji Shirai：“使用透明阳极和发射电子显微镜观察电子发射点”日本电气工程师学会放电研究组的材料 ED-98-204（1998）。

K.Shirai: "Electron Emission Microscope Designed for Field Emission Sites Observation(in Japanese)" J.the Vacuum Society of Japan. Vol.41. 344 (1998)

K.Shirai：“为场发射位点观察而设计的电子发射显微镜（日语）”J.the Vacuum Society of Japan。

S.Kobayashi: "Observations of electron emission sites on broad area electrodes by an electron emission microscope" Applied Surface Science. (in print). (1998)

S.Kobayashi：“通过电子发射显微镜观察大面积电极上的电子发射位点”应用表面科学。