Multipole ion guide operating at elevated pressures

摘要

A device and method for transporting ions along a longitudinal direction in an elevated gas pressure region. The device includes a multipole ion guide having a set of rods positioned along the longitudinal direction on an inscribed diameter equal to or less than 3.5 mm, a voltage source which provides alternating voltages to at least a subset of the rods to create a trapping field in a transverse direction, and a conductance limit having an opening d and placed at the exit of the multipole ion guide. At the end of this configuration near the opening of the conductance limit, a converging continuum gas flow through the conductance limit is provided that transfers the ions collimating near a center of the ion guide into a low gas pressure region. The method injects ions into the elevated gas pressure region of the ion guide, and transports the ions in the converging continuum gas flow into the low gas pressure region.