| 摘要 |
An ion transport apparatus includes an ion entrance end, an ion exit end, and electrodes arranged along a longitudinal axis from the ion entrance end toward the ion exit end. The electrodes are configured for applying an RF electrical field that varies along the longitudinal axis such that at the ion entrance end, the RF electrical field comprises a major first multipole component of 2n1 poles where n1≧3/2, and at the ion exit end the RF electrical field comprises predominantly a second multipole component of 2n2 poles where n2≧3/2 and n2<n1. |
