Amalgam retainer

摘要

An arc discharge lamp comprises an arc chamber having an amalgam tip attached to and communicating with it. The communication comprises a narrow tubular extension that penetrates the amalgam tip for a distance less than the depth of the tip. An amalgam that includes bismuth is contained within the amalgam tip. This construction allows operation of the lamp in any position and prevents the bismuth in the amalgam from penetrating the lamp and poisoning the phosphor.