Segmented gate drive for dynamic beam shape correction in field emission cathodes
US6429596B1 · kind B1 · utility
5Cited by
24References
26Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1999 |
| Grant date | Aug 6, 2002 |
| Priority date | — |
| Expiry date | Dec 31, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J3/022
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A field emission cathode providing for dynamic adjustment of beam shape is disclosed. Beam shape adjustment is accomplished by segmenting the gate electrode of a gated field emission cathode and independently driving the various gate segments to form the desired beam shape. Segments can be turned on and off as the beam is deflected allowing dynamic correction of aberrations in the beam. A focus lens can be placed on the gated cathode to produce a parallel electron beam. In addition, a hollow cathode can be produced to minimize space charge repulsion in a beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.