Abstract: Disclosed is a short-arc high intensity discharge lamp having an improved arc tube as its light source. The arc tube contains an inert gas and a dosage comprising Indium (In), Mercury (Hg), Dysprosium (Dy), and Iodine (I).

Abstract: A short-arc discharge lamp having a pair of electrodes sealed through stems into a bulb, and an external starting device comprising an electrical conductor extending from the vicinity of the stem of one of the electrodes to the vicinity of the stem of the other electrode.

Abstract: A metal halide high-intensity arc discharge lamp having a bulb containing elongated electrodes of a refractory metal such as tungsten, and means connecting the electrodes through seals of the bulb to external terminals. Cooling means such as metal fins are provided at the external terminals and function to cool the electrodes relatively quickly whenever the arc discharge terminates, without substantially affecting the desired high operating temperature of the electrodes. The faster cooling of the electrodes upon termination of the arc discharge permits the lamp to be restarted sooner.