1998 Fiscal Year Final Research Report Summary
Studies on Electrode Surface Conditions and Vacuum Breakdown Phenomena by an Electron Emission Microscope
| Project/Area Number |
09650309
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
電力工学・電気機器工学
|
|---|
| Research Institution | Saitama University |
|---|
Principal Investigator |
KOBAYASHI Shinichi Saitama University, Dept of Electrical and Electronic Systems, Professor, 工学部, 教授 (40008876)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Keywords | Field Electron Emission / Electron Emission Microscope / Electrical Breakdown in Vacuum / Vacuum Microelectronics / Vacuum Electron Sources |
|---|
| Research Abstract |
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.
|
