| 摘要 |
PROBLEM TO BE SOLVED: To lower the detection limit for an object element to be measured, by reducing the size of an ion beam passing hole which divides an ion lens part and a mass selecting part, and lowering a vacuum degree, between a skimmer cone and an opening plate, by a gas introduced from a sampling cone. SOLUTION: The downstream side of the skimmer cone 34 of an ion lens part, and a mass selecting part on which a mass filter 52 is provided, are divided by an opening plate 104. A vacuum degree, between the skimmer cone 34 and the opening plate 104, is lowered by about 1×10<-3> Torr, by reducing the size of the ion beam passing hole 106 of the opening plate 104, and by gas (e.g. Ar) introduced from a sampling cone 32. Consequently, the number of ions related to argon such as ArCl, ArO, and Ar2 , infiltrating into the mass filter 52 side by the lowering of the vacuum degree, can be reduced, for lowering the detection limit of a object element to be measured such as Fe, As, and Se. |
