Schottky emission cathode and a method of stabilizing the same
US5616926A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1995 |
| Grant date | Apr 1, 1997 |
| Priority date | — |
| Expiry date | Jul 31, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/06316
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A Schottky emission cathode has a filament, a needle-shaped piece of single crystal refractory metal which is attached to the filament and has a flat crystal surface at a tip thereof, and an adsorbed layer including at least one kind of a metal other than the single crystal refractory metal on the flat crystal surface. The piece of single crystal refractory metal is heated by passing a current through the filament and electrons are extracted by an electric field applied on a tip of the needle-shaped piece of single crystal refractory metal. The tip of the needle-shaped piece of single crystal refractory metal as a radius of curvature of a value to produce an energy width among electrons extracted from the tip not exceeding a predetermined value when the electric field is sufficient to prevent the flat crystal surface from collapsing during operation of the cathode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.