Service life of a copper bromide vapor laser

An investigation was made of two discharge tubes of the same design. In one tube both windows and electrodes were in a cold zone where the working substance could be ejected. In the second tube both windows and electrodes were heated to prevent the escape of the working substance. The average output power of laser radiation emitted from both tubes was 1.7 W and the efficiency was 0.24%. In the first tube the average power fell to half the initial value after operating for 40 h. The second tube operated for 240 h without a significant reduction in the output power and it failed because of leakage.