| 摘要 |
PURPOSE:To stably execute processing over a long period of time without allowing dust, etc., to stick to a mirror and without allowing the mirror to be overheated by housing the mirror into a container-shaped mirror supporting nozzle and blowing gas to the mirror. CONSTITUTION:The gas is supplied from a gas introducing pipe to maintain a positive pressure in a mirror supporting nozzle 21 made of copper. The inside surface 2 of a cylinder 1 is irradiated with a laser beam 3 in this state. The fumes and dust 29 are generated from the irradiated point and the infiltration of the fumes and dust 29 into the mirror supporting nozzle 21 made of the copper is suppressed by the gaseous flow 31 from an aperture 9. The gas from the gas introducing pipe 27 is blown to the surface of the copper mirror 7 in spite of the slight infiltration thereof and the sticking thereof to the copper mirror 7 surface is prevented by the gaseous flow 32. |
