| 摘要 |
PURPOSE:To increase life of X-ray source and decrease vibration by supporting a rotating axis of a target in a non-contact state by an air bearing, and maintaining it in a vacuum condition by clearance vacuum seal. CONSTITUTION:An air bearing 24 consists of an orifice which blows air to a rotating shaft 12a, and supports the rotating shaft by air pressure without being in contact with the rotating shaft 12a. A clearance seal 25 has an L-shaped cross section, and a distance between the edge of the upper side 25a of the clearance seal 25 and the surface of the rotating shaft 12a is set to 15-20mum. When a chamber 25b is primarily exhausted by, for example, a rotary pump through an exhaust pipe 25c, leakage of air to a vacuum chamber 11 is prevented. The vacuum chamber 11 is secondarily exhausted by a turbo molecular pump through an exhaust pipe 26 to keept it high vacuum. |
