Multipole expansion in quadrupolar devices comprised of planar electrode arrays

Abstract Ion trap mass analyzers made using arrays of independent electrodes allow unprecedented control and variability of electric field shapes. We present a method to select and implement specific values for higher-order multipoles, which are known to affect ion trapping and mass analysis in quadrupole ion traps. Electrode arrays are amenable to microfabrication techniques, hence this method can be used to improve performance in miniaturized ion trap mass spectrometers. With ion traps made using two opposing electrode array plates, both even- and odd-order multipoles can be independently adjusted.