An ultraviolet mercury low-pressure amalgam lamp includes a tube having a first end and a second end, a first electrode placed in the first end of the tube, and a second electrode placed in the second end of the tube, whereby when the lamp is energized a discharge path is formed between the first and second electrodes. At least one amalgam deposit is adjacent to one of the first and second electrodes out of the discharge path between the first and second electrodes. The tube has at least one constriction, wherein the at least one amalgam deposit is placed behind the constriction with respect to the discharge path such that the at least one amalgam deposit is protected by the constriction from the heat emitted by the electrodes.