| 摘要 |
In eight electrodes (31 to 38) arranged at an interval of a rotational angle of 45° around an ion optical axis (C), two neigboring electrodes are electrically connected together as one group, and electrodes in alternate groups are also electrically connected together. A voltage V DC +vcosÉt is applied to electrodes (31, 32, 35, and 36) in alternate groups around the optical axis C, and a voltage V DC -vcosÉt is applied to the other electrodes (33, 34, 37, and 38). Then, while an ion guide has the same electrode structure as that of an octupole-type ion guide, a radio-frequency electric field mainly having a quadrupole field component is formed, and the ion guide can be used as a quadrupole-type ion guide. Accordingly, only by changing the wiring for applying a voltage by using the electrodes having the same structure, ion guides of, for example, a quadrupole type and an octupole type, having different properties such as ion receiving properties and ion passing properties can be achieved. |
