摘要 |
A mass or mass to charge ratio selective ion trap is disclosed having an increased charge storage capacity. A RF voltage acts to confine ions in a first (y) direction within the ion trap. A DC voltage and/or an RF voltage acts to confine ions in a second (x) direction within the ion trap. A quadratic DC potential well acts to confine ions in a third (z) direction within the ion trap. Ions are excited in the third (z) direction and are caused to be mass or mass to charge ratio selectively ejected in the third (z) direction. |