The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Field emission (FE) cathodes made from carbon nanotube (CNT) fibers have demonstrated high emission currents, low turn-on voltages, long lifetimes and offer considerable potential for use as electron sources for vacuum electronic devices. CNT fibers were fabricated by wet-spinning of pre-made CNTs1 and consist of CNT fibrils held together by van der Waals forces. The fibers were 50μm in diameter and...
High direct currents of 2.0 mAmps for a 15 micron diameter single walled nanotube (SWNT) fiber were achieved. Highly aligned, dense SWNT morphology in the fiber was demonstrated to reduce threshold emission and improve resilience to Joule heating. SWNT fibers were exposed to ion bombardment and the effects on emission were evaluated.
In this paper, we present the development of CNT based Field Emitter arrays by Electrophoresis method using CsI as surface modifying element. The electron emission increased as well as the turn on field reduced to greater extent. When compared to cathode of same dimensions without cesium iodide, the emission current increased 7 times with the field 3 times less. From the Fowler-Nordheim plots a reduction...
Small diameter, high current density electron beams are needed for the small beam tunnels required for high frequency traveling wave tube (TWT) amplifiers. The Air Force Research Laboratory (AFRL) began research on small diameter (<;100μm) single fiber DC cathodes for this application. Two types of fibers were tested. Fibers made from graphite were compared to fibers made solely from single walled...
Field emission cathodes have been a research topic for many decades, with recent interest centering on carbon nanotube (CNT) and carbon fiber structures. These cathodes may well prove useful for a variety of applications, ranging from compact millimeter and THz vacuum electronic devices (VEDs), flat panel displays, and compact x-ray sources. In this presentation we describe experiments performed by...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.