H01J1/00—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
H01J1/02—Main electrodes
H01J1/13—Solid thermionic cathodes
H—ELECTRICITY
H01—ELECTRIC ELEMENTS
H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
H01J19/00—Details of vacuum tubes of the types covered by group H01J21/00
H01J19/42—Mounting, supporting, spacing, or insulating of electrodes or of electrode assemblies
H—ELECTRICITY
H01—ELECTRIC ELEMENTS
H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
H01J2893/00—Discharge tubes and lamps
H01J2893/0001—Electrodes and electrode systems suitable for discharge tubes or lamps
H01J2893/0002—Construction arrangements of electrode systems