| 摘要 |
<p>Mass spectrometry is performed by setting a voltage to be applied to each electrode such that an ion on a circulation orbit (3) from an incident gate electrode (5) goes substantially half round the circulation orbit (3) and then goes toward an ion detector (7) from an exit gate electrode (6). A target ion is determined based on the intensity of a peak appearing in a mass spectrum thus obtained, and such a timing as the voltage of the exit gate electrode (6) changes when that ion is not passing through the exit gate electrode (6) during circulation along the circulation orbit (3) is determined. Consequently, the orbit of the target ion can be changed surely toward the ion detector (7) from an exit gate electrode (6) after the target ion circulated a plurality of times along the circulation orbit (3). Consequently, the mass information of the target ion can be obtained surely.</p> |
