Current-stabilizing illumination of photocathode electron beam source
US6847164B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2002 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Dec 10, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/2817
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron beam source has a photocathode with a photoemitter material having a work function, and with a beam receiving portion and an electron emitting portion. A first light source directs a first light beam onto the beam receiving portion of the photocathode to generate an electron beam from the electron emitting portion. The first light beam has a wavelength λ1 such that hc/λ1 is at least about the work function of the photoemitter material, where ‘h’ is Planck's constant and ‘c’ is the speed of light. A second light source directs a second light beam onto the beam receiving portion of the photocathode, such as onto the beam receiving portion, to stabilize the electron beam. The second light beam having a wavelength λ2 such that hc/λ2 is less than about the work function of the photoemitter material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.