CONVERGING DUALFIELD MULTIPOLE ION GUIDES, HYPERBOLIC ION GUIDES AND RELATED METHODS

摘要

An ion guide generates a first r.f. field of order, where N is an integer equal to or greater than 2, and a second r.f. field of order 2.N order superimposed on the first r.f. field. The first and second RF fields may be generated by a respective first and second set of electrodes. Another ion guide may include a converging inlet section followed by an exit section. The converging portion may have a hyperbolic profile. A hyperbolic profile may be represented by electrodes having a twisted configuration relative to an ion guide axis.