Annular ion guide

摘要

An annular ion guide is disclosed comprising inner and outer electrodes. Ions are confined within an annular ion guiding region by RF or pseudo-potential barriers in both an outward and inward radial direction.

主权项

1. An ion guide or ion trap comprising:
a first group of inner electrodes; a second group of outer electrodes; an annular ion guiding region arranged between said first and second groups of electrodes; and a RF voltage device arranged and adapted to apply a RF voltage to said first and second groups of electrodes so that ions are confined within said annular ion guiding region by a first radial RF or pseudo-potential barrier and by a second different radial RF or pseudo-potential barrier; wherein ions are substantially unconfined or unrestrained in a tangential direction which is orthogonal both to a radial direction and to a longitudinal axis of said ion guide or ion trap; and wherein in use one or more transient DC voltages or one or more transient DC voltage waveforms are applied to said first group of inner electrodes or to said second group of outer electrodes or to one or more additional electrodes so that ions are caused to move along the longitudinal axis from one end of said ion guide or ion trap to another end of said ion guide or ion trap.