Cathode material including rare earth metal used as electron emission source for electron beam apparatus
US6800990B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 2001 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | Sep 8, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J1/146
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides a cathode material for an electron beam device. The cathode material is characterized by the fact that it includes 0.5-9.0% by weight of a rare earth metal of the cerium group, 0.5-15.0% by weight of tungsten or rhenium or both tungsten and rhenium, 0.5-10% by weight of carbon and the remainder of iridium. The cathode material according to the invention has excellent plasticity, can be easily used for manufacturing an emitter of a small size, has high electron emission power, and has a low operation temperature, thereby having a long lifetime, and it is therefore useful for a cathode material for an electron beam device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.