IMPROVED AXIAL EJECTION RESOLUTION IN MULTIPOLE MASS SPECTROMETERS

摘要

An improved method of operating a mass spectrometer having a linear ion trapwherein ions are axially ejected from the trap to a detector or subsequentmass analysis stage. The DC barrier field produced at the exit lens of thetrap is scanned in conjunction with the scanning of other fields used toenergize ions of select mass-to-charge ratios past the barrier field/exitlens. The technique can maximize the resolution obtainable from axial ejectionover a wide mass range.