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.
Secondary electron emission (SEE) coefficients of alumina ceramics with three different surface finishes have been measured using a scanning electron microscope with a single-pulse electron beam (100 pA, 1 ms). SEE coefficients of those aluminas with annealing process became lower after mechanical grinding operations even though its average roughness was almost same as those of as-sintered ones. SEE...
Surface breakdown of solid insulator in vacuum is initiated by surface charging which is strongly influenced by electron emission properties of the insulator. In this study, photoelectron emission of alumina exited by vacuum ultraviolet light is observed using an electron emission microscope (EEM). As a result, photoelectron emissions of 99.7% purity alumina ceramic named HA997, sapphire (single crystal...
The breakdown of alumina rf windows is mostly caused by multipactor, as well as by material defects and contamination. Since multipator induces localized surface heating, leading to surface melting, it is necessary to observe secondary electron emission (SEE) coefficients of alumina ceramics under high temperature conditions. The SEE coefficients of commercial alumina ceramics and sapphire were measured...
The breakdown of the alumina RF-windows used in high-power klystrons is one of the most serious problems in the development of klystrons. This breakdown results from excess heating of alumina due to multipactor bombardment and/or localized RF dissipation. In order to develop RF windows having high durability for the KEKB klystrons, several kinds of alumina ceramics are being examined, and the breakdown...
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.