Lanthanated thermionic cathodes
US4083811A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 1974 |
| Grant date | Apr 11, 1978 |
| Priority date | — |
| Expiry date | Jul 8, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J9/042
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A thermionic cathode of tungsten or molybdenum is made with an activating content of lanthanum oxide and is supplied with a carbonaceous reducing agent either by incorporation in the bulk material of the cathode body or by carburizing, so that the reducing agent comprises at least in part a carbide of the carrier metal. Lower operating temperatures and higher emissivity are obtained compared to thoriated tungsten filaments and longer useful life compared to other cathodes activated by other rare earth oxides. The temperature-emissivity characteristics are such that good results are obtainable even within the temperature range in which molybdenum is usable as a carrier material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.