| 摘要 |
PURPOSE:To prevent fluctuation in the laser output by preventing fluctuation in the current speed of laser gas. CONSTITUTION:A gas channel 1b is provided with a straightener grid 5 on the upstream side of a discharge section 4 in a wind tunnel 1. The straightener grid 5 comprises grid bones 5a arranged, at a wide interval 5d, on the downstream side of the boss section of a fan 3 for returning laser gas passing through the grid 5 where the current speed of gas is low and arranged, at a narrow interval 5c, on the downstream side of the impeller section 3b of the fan 3 where the current speed of gas is high. |
