Method of operating an arc discharge lamp and a lamp in which a salt reservoir site is locally cooled to provide a condensation site for iodine remote from the lamp's electrodes

A method of operating an arc discharge lamp and a lamp in which a light transmissive envelope encloses electrode tips, a salt and a fill that includes iodine, and in which after turning the lamp off, a first part of the light transmissive envelope is locally cooled relative to other parts of the light transmissive envelope to provide a condensation site for the iodine that is spaced from the electrode tips, the first part of the light transmissive envelope being where a salt reservoir forms and where the salt is cooled by the local cooling. The local cooling may be provided by an indentation in an outer sleeve around the light transmissive envelope, where the indentation contacts the first part to provide a heat sink.