| 摘要 |
PURPOSE:To increase the exhaust velocity of a pump along with the realization of the stable exhaustion even for rare gas by forming a plate-shaped first cathode and a second cathode comprising a rod-shaped part whose surface is formed with a getter material and a plate-shaped part, while combining them with a cylindrical anode. CONSTITUTION:A plate-shaped first cathode 18 and a second cathode 19 comprising a plate-shaped part 19a parallel to said first cathode and a vertical rod- shaped part 19b whose surface has been formed with a getter material are provided, and therebetween a cylindrical anode 11 having a larger part 11a and a smaller part 11b in their inner diameters is provided surrounding said rod-shaped part 19b. And, said anode and cathodes are arranged in a vacuum vessel. Further, a magnet 23 is provided around said vacuum vessel, and a magnetic field parallel to said rod-shaped part 19b is applied into a hollow part 12. And, gas molecules ionized by a group of electrons within the hollow part 12 are forced to collides with the rod-shaped part 19b to sputter a getter material on the surface of said rod-shaped part. Accordingly, it is possible to largely increase the amount of the sputtered material, allowing the exhaust velocity to be increased. |
