Traveling-wave tube with confined-flow periodic permanent magnet focusing
US4942336A · kind A · utility
Inventors
Key dates
| Filing date | Apr 18, 1988 |
| Grant date | Jul 17, 1990 |
| Priority date | — |
| Expiry date | Apr 18, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J23/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A traveling-wave tube (10) has a confined-flow periodic permanent magnet focusing arrangement (26) in which either the first magnet (60f) or the third magnet (60t) from the electron gun (12) has an extent or axial thickness along the electron stream path which is one-half that of the remaining magnets in the arrangement, thereby providing a scalar magnetic potential of essentially zero on the electron gun pole piece (46), thereby eliminating the field reversal at the cathode (14). This enables a magnetic field to be provided in the region of the electron gun between the gun pole piece (46) and a location behind the cathode due solely to the magnetic field leaking through the gun pole piece aperture (50). The axial magnetic field within the electron gun (12) may be tailored or fine tuned, by varying the size of the aperture (50) in the gun pole piece (46).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.