Ion manipulation cell with tailored potential profiles

An ion cell having an axis, comprising a sheath of individual electrodes that extends along the axis and defines an internal volume, where adjacent individual electrodes are electrically insulated from each other, where the individual electrodes each receive a DC potential and RF voltage, and where at least some of the individual electrodes have a width that varies in the axial direction such that an electrical effect on an axis potential varies along the axis of the ion cell, where the individual electrodes form longitudinal groups, and where each longitudinal group extends between two ends of the ion cell and has an equal width over a length of the ion cell.

A method for using an ion cell having an axis, where the ion cell includes a sheath of individual electrodes that extends along the axis defining an internal volume, where adjacent individual electrodes are insulated from each other, and where at least some of the individual electrodes have a width that varies in the axial direction such that an electrical effect on an axis potential varies along the axis of the ion cell, where the individual electrodes form longitudinal groups, and where each longitudinal group extends between two ends of the ion cell and has an equal width over a length of the ion cell, the method comprises providing a DC potential and a RF voltage to each of the electrodes.

A method for using an ion cell having an axis, where the ion cell includes a sheath of individual electrodes that extends along the axis defining an internal volume, where adjacent individual electrodes are insulated from each other, and where at least some of the individual electrodes have a width that varies in the axial direction such that an electrical effect on an axis potential varies along the axis of the ion cell, the method comprises providing a DC potential and a RF voltage to each of the electrodes, further comprising using the ion cell in a mass spectrometer, and measuring harmonic oscillations of ions within the mass spectrometer, where the individual electrodes form longitudinal groups, where each longitudinal group extends between two ends of the ion cell and has an equal width over a length of the ion cell, and where each longitudinal group forms cylindrical sheath segments that are divided by parabolic separating gaps.