Gas laser tube

Claim 1

A gas laser tube with a vacuum envelope, comprising: a tubular section formed of an electrically insulating material with a coefficient of thermal expansion χ 1 ; an end section formed of an electrically insulating material with a coefficient of thermal expansion χ 2 , such that ##EQU8## wherein i=1, 2; and a transition element connecting said tubular section to said end section; said transition element including a first metallic section in the form of a first metal ring adjacent said tubular section and a second metallic section in the form of a second metal ring, said first and second metallic sections having different respective coefficients of thermal expansion χ 3 and χ 4 ; said first metallic section being thermally matched to said tubular section such that ##EQU9## wherein m=1, 3; said second metallic section being thermally matched to said end section such that ##STR3## wherein n=2, 4; said first and second metallic sections having end surfaces with mutually supplementary steps formed therein being disposed inside each other; said first and second metallic sections having inner wall surfaces being joined together; said metal rings having ends facing each other, said mutually complimentary steps including outer and inner ridges in the form of a respective sharp increase of the inner wall surface area of one of said metal rings at said end thereof, and a respective sharp reduction of the diameter of the outer periphery of the other of said metal rings; and in said transition element; the ratio of the inner diameter to the total length thereof is between 0.5:1 and 1.5:1; the ratio of the length of one of said metal rings to the length of the other is between 0.7:1 and 1.3:1; and the ratio of the wall thickness to the total length is between 0.06:1 and 0.15:1.