| 摘要 |
Mass selective ion traps are disclosed having increased space charge capacities. In one embodiment, the ion trap comprises a toroidal ion trapping region, ions being trapped in a first (y) direction by a pseudopotential well and in a radial direction (r) by a quadratic DC potential well. Ions are excited in said radial direction (r) so as to mass selectively eject ions in said same direction. In other embodiments (see Figures 3A-4C), an expanded three dimensional array of electrodes is arranged in two horizontal layers. A RF voltage acts to confine ions in a first (y) direction within a non-quadrupolar pseudopotential well, while a DC voltage and/or an RF voltage acts to confine ions in a second (x) direction within the ion trap. Ions are excited in a third z-direction within a quadratic potential well so as to be mass-selectively ejected in said third (z) direction. |
