| 摘要 |
PURPOSE:To facilitate the replacement by providing a first and a second partitions mutually so as to prevent leakage of a ultra-high vacuum of a long linear part, and also, providing a gate valve on a boundary part of a long linear part of a beam line and a helium chamber. CONSTITUTION:At the time of replacing a beryllium window 23 of a partition of a gate valve 181, first of all, by operating each gate valve provided on a long linear part, the inside of a helium chamber is allowed to form a vacuum. Subsequently, by turning a valve driving knob 30 of the valve 181, a partition cam holding plate 24 is pushed up. Next, a major axis side of partition pushing cams 311, 312 is raised, pressure to a side face 481 is slackened and the partitions 32, 371 are drawn up, and when the tip part of the partition 32 hits against a stopper 34, the partitions 32, 371 stop. When the holding plate is further drawn up, a major axis side of cams 361, 362 for partition holding plate is pushed down sidelong, the partition 371 is pressed against the side wall 481 of a body 40, and by a visible ray transmission window 41, an X-ray transmission hole 43 is closed up tightly. Thereafter, by opening a helium leading-in port, the inside of the helium chamber is set to the atmospheric pressure, a closing plate 28 is removed by drawing out a set screw 291, and a window 23 is removed by drawing out a set screw 22, and replaced with a new window. |
