Abstract
Novel designs of field emission cold cathodes are resulting from material development of high strength/high temperature composites and thin film vacuum deposition techniques. The composite materials are principally tungsten needle or, more recently, refractory metal carbide types such as Ta, V and Nb and provide long life times in excess of a thousand hours. The thin film deposition techniques provide methods of depositing extraction electrodes directly around the emitting needle points and hence enables a low anode voltage to be used resulting in life times in excess of 7000 h. Current densities of up to 30 A cm−2 under dc conditions with a gross current of 100 mA have been reported.
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.
