Supports for the emissive material

Full Title

Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps (details of electron-optical or ion-optical arrangements H01J3/00) > Main electrodes > Solid thermionic cathodes > Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment > Supports for the emissive material