Abstract: A compact ionization source includes first and second electrodes, each having a plurality of fingers that are interdigitated with each other. The spacing between the first and second electrode, preferably less than 1 mm, creates a large electric field when a potential is applied across the first and second electrodes. The large electric field creates an ionization volume between the fingers of the first and second electrode and ionizes a portion of the molecules occupying the ionization volume. The interdigitated fingers of the first and second electrodes allow for a narrow gap separating the electrodes while presenting a large flow area for ionizing molecules for downstream analysis.

Abstract: An ion gate is disposed between a first volume occupied by a first carrier gas and ions of the first carrier gas and a second volume occupied by a second carrier gas. The ion gate includes at least one channel connecting the first volume to the second volume, a first electrode disposed on an inlet surface of the ion gate facing the first volume, and a second electrode disposed on an outlet surface of the ion gate facing the second volume. Ions are transported from the first volume to the second volume through the channel under an electric field produced by the first and second electrode.