Abstract
A new type dispenser cathode with Os-W/Re dual-layer has been developed. Emission performance and surface microstructure of the cathode with the dual-layer before and after ageing were studied. The performance of the dispenser cathode is improved by introducing a Re intermediate leyer. DC current density of the dispenser cathodes coated with Os-W alloy and Os-W/Re were compared. It is found that the cathode with Os-W/Re shows better emission performance than the cathode with Os-W alloy. Both cathodes were investigated using X-ray photoelectron spectroscopy after full activation. Ternary alloy coating being formed for the cathode with Os-W/Re is the major reason for its better emission performance. Scanning electron microscopy was used for investigating surface microstructures of both kinds of cathodes and the results show that the emitting surface of the cathode with Os-W alloy after ageing appeared non-adherent (flaking) in localized areas. This is one of the reasons for its non-uniform emission. However, surface of the cathode with Os-W/Re does not suffer from peeling under the same conditions, thus ensuring better emission uniformity and functional reliability of the dispenser cathode.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
