Field emission electron gun system
US4945247A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1989 |
| Grant date | Jul 31, 1990 |
| Priority date | — |
| Expiry date | Jun 14, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/073
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a field emission electron gun system with a multi-stage acceleration tube comprising a field emission electron source, a field emission electrode for extracting the electrons, a magnetic lens having a magnetic gap between the field emission electron source and the field emission electrode or a magnetic lens having a magnetic pole which also serves as the field emission electrode, and at least two-stages of acceleration electrodes for accelerating the electrons, a magnetization current I for the magnetic lens is changed interlocking with a field emission voltage V.sub.1 applied between the field emission electron source and the field emission electrode so that IN/.sqroot.V.sub.1 (N: the number of windings of the magnetic lens) takes a predetermined value and a first acceleration voltage V.sub.2 applied between the field emission electron source and the first-stage acceleration electrode is changed interlocking with the field emission voltage V.sub.1 so that V.sub.2 /V.sub.1 takes a predetermined value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.