| 摘要 |
PURPOSE:To replace an ion source with a new one while keeping a vacuum state by mounting the plural ion sources on branch ends of a branch tube respectively via valves and rockably and hermetically connecting a root portion of the branch tube to an ion beam introducing tube via a bellows. CONSTITUTION:A primary ion beam 7 is introduced from an ion source 6 to an ion beam introducing tube 1. After the ion beam is subjected to mass separation by a mass separator 2, its diameter is reduced by a beam diameter reducing system 8 in a measuring chamber 3, and radiated onto the surface of a specimen 4. Secondary ions 11 emitted from the specimen 4 are introduced into a mass spectrometer 5 for analyzing a composition of the surface of the specimen 4. The ion sources 6a, 6b are mounted on branch ends 8a of a bifurcated branch tube 8 respectively via valves 9. In addition, a root part 8b at which the respective branch ends 8a meet is rockably and hermetically connected to the introducing tube 1 via a metal belows 10. Rocking of the branch tube 8 by an angle theta enables a desired ion source 6 to be prepared on the axis of the introducing tube 1. |
