Apparatus and method for providing a modulated electron beam
US4703228A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 28, 1985 |
| Grant date | Oct 27, 1987 |
| Priority date | — |
| Expiry date | Aug 28, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2201/342
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron gun for emitting a modulated electron beam. The gun includes an evacuated envelope having an output end with a photocathode positioned in the envelope and responsive to light to emit electrons. An anode is positioned between the photocathode and the output end for accelerating the electrons emitted by the photocathode. The gun further includes a source of potential interconnecting the anode and the photocathode for maintaining the anode electrostatically positive relative to the photocathode. A first laser provides a first laser beam at a first frequency illuminating the photocathode, and a second laser provides a second laser beam at a second frequency illuminating the photocathode at the same time. The first frequency differs from the second frequency by a beat frequency, whereby the photocathode provides the electron beam with the electrons spacially bunched in accordance with the beat frequency. A method of providing a modulated electron beam is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.