| 摘要 |
PROBLEM TO BE SOLVED: To provide a spectroscope allowing ion to smoothly pass without being scattered, through an orifice provided on a partition wall for partitioning two spaces different in the degree of vacuum by providing an accelerating electric field and a decelerating electric field in succession on a flying trajectory of ion to accelerate and then to decelerate ion. SOLUTION: An accelerating lens and a decelerating lens are provided in an ion flying space between a prestage and a post-stage of an orifice 10, that is, between an ion guide 2 and a converging lens 4, of a mass spectroscope. Ion flying in the linear flying space is once accelerated by the accelerating electric field formed by the accelerating lens, to swiftly pass the orifice 10 provided on a partition wall between an intermediate chamber 3 and a measuring chamber 9, and then decelerated again into the original position by the decelerating electric field formed by the decelerating lens. Since the flying speed is increased only when passing through the orifice 10, an ion trajectory is not distorted by the fouling or the like of the orifice, so that ion is hardly scattered. |
