Abstract: A gas discharge lamp comprising an electrode including a carrier of an electrode metal, selected from the group formed by tungsten and tungsten-containing alloys, and a first coating of a first electron-emitting material, which material comprises an alkaline earth metal oxide, selected from the group formed by calcium oxide, strontium oxide and barium oxide, and a rare earth metal oxide, selected from the group formed by scandium oxide, yttrium oxide and europium oxide, in a quantity a that ranges from 0.1 to 10 wt. % by weight, is characterized by a longer service life, a higher resistance to poisoning and a robust manner of coping with a rapid succession of switching operations, as well as a short ignition stage.

Abstract: A gas discharge lamp, in particular a low-pressure gas discharge lamp, comprising an electrode including a carrier of an electrode metal and a first electrode coating of an electron-emitting material, which material comprises a metal powder preparation of a powder of a reducing metal selected from the group formed by aluminum, silicon, titanium, zirconium, hafnium, tantalum, molybdenum, tungsten and the alloys thereof, which metal powder preparation is provided with a powder coating containing a noble metal selected from the group formed by rhenium, cobalt, nickel, ruthenium, palladium, rhodium, iridium and platinum, and the alloys thereof, and said material comprising at least one alkaline earth metal oxide selected from the group formed by calcium oxide, strontium oxide and barium oxide, is characterized by a uniform emission current and a long service life.

Abstract: An electric discharge tube or discharge lamp comprising a scandate dispenser cathode which is composed of a cathode body and a coating having an emissive surface, said cathode body including a matrix of at least one refractory metal and/or a refractory alloy and a barium compound which is in contact with the matrix material to supply barium to the emissive surface by means of a chemical reaction with said matrix material, and the coating containing one or more multilayers which may include a bottom layer of tungsten and/or a tungsten alloy, an intermediate layer of rhenium and/or a rhenium alloy and a top layer of scandium oxide, a mixture of scandium oxide and rare-earth metal oxides, a scandate and/or a scandium alloy, is characterized by a long service life and a high emission-current density.