Schottky emitter having extended life
US6680562B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 2000 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | Dec 22, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J1/15
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A electron emission cathode includes an emitter having an apex from which electrons are emitted. The emitter is attached to a heating filament at a junction and extends from the junction both forward toward the apex and rearward. A reservoir of material that lowers the work function of the emitter is positioned on the rearward extending portion of the emitter. By positioning the reservoir on the rearward extending portion, the reservoir can be positioned sufficiently far from the junction to reduce its temperature and thereby greatly increase the useful life, of the emitter without adversely affected the emission characteristics of the source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.