H01J13/00—Discharge tubes with liquid-pool cathodes, e.g. metal-vapour rectifying tubes
H01J13/02—Details
H01J13/04—Main electrodes; Auxiliary anodes
H—ELECTRICITY
H01—ELECTRIC ELEMENTS
H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
H01J2893/00—Discharge tubes and lamps
H01J2893/0072—Disassembly or repair of discharge tubes
H01J2893/0073—Discharge tubes with liquid poolcathodes; constructional details
H01J2893/0074—Cathodic cups; Screens; Reflectors; Filters; Windows; Protection against mercury deposition; Returning condensed electrode material to the cathodic cup; Liquid electrode level control