Patent ID: 8987661
Filing Date: 2015-03-24
Classification: H01J

Abstract:
1. An ion trap comprising: a first electrode set comprising a first plurality of electrodes, wherein said first plurality of electrodes comprises a first quadrupole rod set; a second electrode set comprising a second plurality of electrodes, wherein said second plurality of electrodes comprises a second quadrupole rod set, wherein said second electrode set is arranged downstream of said first electrode set; a first device arranged and adapted to apply one or more DC voltages to said second quadrupole rod set; a second device arranged and adapted to vary, increase, decrease or alter a radial displacement of at least some ions within said ion trap; wherein: said second device is arranged and adapted to apply one or more excitation, AC or tickle voltages to at least some of said first plurality of electrodes in order to excite in a mass or mass to charge ratio selective manner at least some ions radially within said first electrode set so as to increase in a mass or mass to charge ratio selective manner a radial motion of at least some ions within said first electrode set in at least one radial direction; and said first device is arranged and adapted to apply said one or more DC voltages to said second quadrupole rod set so as to create a radially dependent axial DC potential barrier so that: (a) ions having a radial displacement within a first range experience a DC trapping field, a DC potential barrier or a barrier field which acts to confine at least some of said ions in at least one axial direction within said ion trap; and (b) ions having a radial displacement within a second different range experience a DC extraction field, an accelerating DC potential difference or an extraction field which acts to extract or accelerate at least some of said ions in said at least one axial direction or out of said ion trap; wherein ions are ejected axially from said ion trap in an axial direction within axial kinetic energy and wherein a standard deviation of the kinetic energy is in a range selected from the group consisting of: (i) <1 eV; (ii) 1-2 eV; and (iii) 2-3 eV.