| 摘要 |
PURPOSE:To hold a hermetical seal by holding a mirror in a mirror mount formed with a cutout to contain the mirror, and disposing a flat packing for sealing to cross over the periphery of the mirror and the periphery of the cutout of the mount. CONSTITUTION:A laser mirror 2 is brought into contact with the periphery with a contacting surface 6 (reference surface) of the mirror 2 at a vessel side for containing the mirror 2, a flat packing 3 is so disposed as a sealer as to cross over both the periphery of the mirror and a mirror mount 1, a sealing retainer 4 cut to just contain the packing 3 is provided, and clamped with clamping screws 5. Accordingly, the mirror 2 is contacted directly with the surface which becomes a reference surface of the mount 1 of the vessel side, and when the vessel is in vacuum, the exterior is at the atmospheric pressure. Accordingly, the mirror is pressed by the atmospheric pressure to the reference surface of the mount of the vessel side. Thus, mechanical dimensional accuracy is improved, the influence of clamping force is eliminated, the mirror is not deformed, not damaged, and can be hermetically sealed under vacuum or the pressure higher than the atmospheric pressure. |
