0 001 in cathode overwind 0 005 in u00b1 0 005 in 0 007 in u00b1 0 001 in wire a mismatch between electrical operating characteristics and electrode design could be disastrous from a product performance standpoint generally a design that permits too high of an operating temperature of the electrodes high current small electrodes will result in rapid electrode erosion darkening of the envelope short life and low light output too low of an operating temperature of the electrode low power large electrodes will result in an unstable or flickering arc in has been discovered that a unique sodium free metal halide mixture of individual compounds selected from the following group of scandium iodide indium iodide and cesium iodide in conjunction with the other fill components results in a lamp which exhibits enhanced uv output it is the specific dose of metal halide salts in combination with a reflector having a dichroic coating that concentrates only the desired lw radiation that is the key combination of components of the present invention the scandium iodide or any other suitable lanthanide provides a means of controlling undesired secondary processes within the lamp the indium iodide contributes radiation emission in the blue to ultraviolet regions to enhance the total spectral output fundamental to.