Patent ID: 8817833

Claim:
A gas laser comprising: a plurality of discharge tubes, the discharge tubes being connected to together by corner housings, each corner housing comprising a mirror element for guiding a laser beam and a first cooling channel configured to allow flow of a first coolant; a primary heat exchanger circuit comprising a plurality of second cooling channels configured to allow flow of a second coolant, wherein each second cooling channel is configured to cool laser gas prior to the laser gas entering into one of the corner housings; and at least one temperature control device being selected from the group consisting of a laser gas cooling device, a coolant temperature control assembly configured to generate a temperature difference between the first coolant flowing in the first cooling channel of the corner housing and the second coolant flowing in the second cooling channel of the primary heat exchanger circuit, and combinations thereof, wherein the at least one temperature control device is configured to maintain a temperature difference of less than approximately 5 K between the first coolant flowing through the first cooling channel of the corner housing and the laser gas entering into the corner housing.