DISCHARGE LAMP WHICH INCORPORATES CERIUM AND CESSIUM HALIDES AND A HIGH MERCURY LOADING

摘要

Arc-discharge device wherein the discharge-sustaining filling includes as essential elements predetermined amounts of at least one of praseodymium halide, neodymium halide and cerium halide plus cesium halide and sufficient mercury to provide an operating mercury-vapor pressure of from 3 to 15 atmospheres, in addition to the usual starting gas. The rare-earth metal halide provides a very efficient discharge and the cesium halide plus the high mercury loading permits a high efficiency to be obtained with a relatively low minimum envelope temperature. Other discharge-sustaining materials desirably are added to the foregoing essential constituents to modify the color of the discharge.