A UV lamp unit is provided and comprises a lamp in the form of a mercury
low pressure amalgam lamp that is provided with at least one amalgam
deposit. A cladding tube surrounds the lamp in such a way that an air gap
is provided between the lamp and the cladding tube. An element is
provided in one axial direction of the lamp, in the region of the at
least one amalgam deposit, for influencing the temperature of the
amalgam.