A linear ion trap configured for mass selective axial ejection comprising: a pair of parallel continuous conductive rods ; a pair of parallel segmented conductive rods each having a long segment and a shorter segment disposed at an exit end of the linear ion trap, wherein the two pairs of conductive rods are axially aligned to be parallel with one another and coextensive in the axial direction, wherein in said two pairs of rods are interleaved with one another such that each conductive rod in a pair is diagonal to the other conductive rod in that pair; an RF signal generating source configured to supply an RF signal having a first RF voltage and a first frequency to each rod in the pair of parallel continuous conductive rods and a second RF voltage of the same frequency and the same voltage and at opposite phase to the first RF voltage to the long segment of each rod in the pair of parallel segmented conductive rods; a pair of capacitors that electrically couples the RF signal from the long segments to the shorter segments of the segmented conductive rods, such that a voltage of the RF signal applied to the shorter segment is reduced by at least 1% relative to the first RF voltage of the RF signal; a DC voltage source configured to provide a first DC voltage to the long segment of each rod in the pair of parallel segmented conductive rods and a second higher DC voltage to the shorter segment of each rod in the pair of parallel segmented conductive rods; and an exit lens , located between the linear ion trap and an ion detector ; wherein the RF signal generating source is configured to apply an auxiliary AC signal, at a lower voltage and frequency than the RF signal, to the pair of parallel continuous conductive rods during an axial ejection procedure. a pair of parallel continuous conductive rods ; a pair of parallel segmented conductive rods each having a long segment and a shorter segment disposed at an exit end of the linear ion trap, wherein the two pairs of conductive rods are axially aligned to be parallel with one another and coextensive in the axial direction, wherein in said two pairs of rods are interleaved with one another such that each conductive rod in a pair is diagonal to the other conductive rod in that pair; an RF signal generating source configured to supply an RF signal having a first RF voltage and a first frequency to each rod in the pair of parallel continuous conductive rods and a second RF voltage of the same frequency and the same voltage and at opposite phase to the first RF voltage to the long segment of each rod in the pair of parallel segmented conductive rods; a pair of capacitors that electrically couples the RF signal from the long segments to the shorter segments of the segmented conductive rods, such that a voltage of the RF signal applied to the shorter segment is reduced by at least 1% relative to the first RF voltage of the RF signal; a DC voltage source configured to provide a first DC voltage to the long segment of each rod in the pair of parallel segmented conductive rods and a second higher DC voltage to the shorter segment of each rod in the pair of parallel segmented conductive rods; and an exit lens , located between the linear ion trap and an ion detector ; wherein the RF signal generating source is configured to apply an auxiliary AC signal, at a lower voltage and frequency than the RF signal, to the pair of parallel continuous conductive rods during an axial ejection procedure. <EOS>