| 摘要 |
PURPOSE:To prevent soot of metallic vapor from moving to the side of a window and the window from being eroded or broken by providing a partition having through holes passed by laser beams at both ends and in the intermediate part of a pressurized room. CONSTITUTION:A fuel rod A is inserted into a screw member 34 and the left end part is brought into contact with the edge part of a hole of a cylindrical body 25. Then, the end face of a wind mount 8 is pressed to the end face of a chamber 20, the air in the pressurized room 26 is evacuated. Then, helium gas is supplied from an inlet into the pressurized room 26 to substitute the inner part of the fuel rod A for helium gas. The laser beams are focused by a lens 40, transmits the window 10, irradiates the end part of the fuel rod A, welds and blocks the hole formed at a terminal plug of the fuel rod A. At this time, metallic vapor makes soot but it is hard for the soot to move to the window side by the partition of the cylindrical body 24. Then, if helium gas is discharged from the outlet, it flows from a room 26a to a room 26b, the soot, too, moves to the room 26b side but since the inside of the partition is tapered, the soot moves smoothly, hardly adheres to the window 10 and the window 10 is prevented from being eroded or broken. |
