Patent ID: 11501962

Abstract:
A mass spectrometer collision cell system, comprising: a gas containment vessel comprising an internal chamber having ion inlet and ion outlet ends and a cross-sectional area, Achamber; a gas inlet aperture; first and second gas outlet apertures that are disposed at or proximal to the ion inlet and outlet ends, respectively, and that have respective outlet aperture cross-sectional areas, Aaperture1 and Aaperture2, and an average outlet aperture cross-sectional area, Aapertureave; a longitudinal axis of the chamber extending from the ion inlet end to the ion outlet end and having a length, Lchamber; and a set of multipole rod electrodes, at least a portion of each multipole rod electrode being within the chamber, wherein the values of Achamber, Lchamber and Aapertureave are such that the combined gas conductance of the chamber and the gas outlet apertures is not greater than 95 percent of the gas conductance of the gas outlet apertures alone.