| 摘要 |
PURPOSE:To obtain the stable performance of laser condensation even in long- time use by a method wherein a mirror substrate is directly cooled with water by interposing a material of good thermal conductivity between the substrate and segments, and the mirror surface is cooled by gas spraying. CONSTITUTION:When a laser beam comes into a segment mirror, heat generation is caused by the photo absorption to the boundary of each segment 2 constituting the segment mirror and to the segment 2 itsselt. This portion of heat generation is first removed by emission loss to some degree by means of a cooling gas 12 spouted through a cooling gas pipe 6. Further, the portion of heat generation transferred to the mirror by thermal conduction is transmitted to the mirror bustrate 1 via material 9 such as Ag solder which has a good thermal conductivity. Here, a cooling water path 4 is provided between a mirror holder 3 and the mirror substrate 1, and the cooling water 11 directly cools the periphery of the substrate 1. |
