| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an apparatus and method for selectively setting a predetermined orbit in such a manner that an electric field crosses a substantially uniform magnetic field (E x B) against an ion of a first mass/charge ratio (m<SB>1</SB>) with respect to an axis. <P>SOLUTION: A magnetic field is directed along an axis, and an electric field has both DC voltage component (Φ<SB>0</SB>) and AC voltage component (Φ<SB>1</SB>). In an operation, when Φ<SB>1</SB>is zero, the voltage Φ<SB>0</SB>is fixedly set for the purpose of positioning an ion (m<SB>1</SB>) on a limited orbit about the axis. When Φ<SB>1</SB>is adjusted to a predetermined value on the other hand, the ion (m<SB>1</SB>) is discharged away from the axis. (E x B) is set within a chamber, whereby the ion (m<SB>1</SB>) is passed through the chamber at the limited orbit (Φ<SB>1</SB>=0), while the ion (m<SB>1</SB>) is radiated onto the wall of the chamber whereon the unlimited orbit (Φ<SB>1</SB>=predetermined value). <P>COPYRIGHT: (C)2004,JPO |
