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US 2012/0267526 A1Published application
Mass Spectrometer
AssigneeMicromass UK Limited
InventorMartin Green
Life of this patent
Estimating the term…
Abstract
An ion trap mass analyser is disclosed comprising a segmented rod set. Ions are trapped radially within the mass analyser by a radial pseudo-potential well. The ions are also confined axially within a quadratic axial potential well. An AC voltage or potential is applied to the electrodes comprising the ion trap mass analyser in order to excite parametrically ions within the ion trap.
Claims24
An ion guide or ion trap comprising:
- a plurality of electrodes;
- a DC voltage supply arranged and adapted to maintain a DC potential trapping profile along at least a portion of an axial length of said ion guide or ion trap in a first mode of operation;
- and
- an AC or RF voltage supply arranged and adapted to apply an AC voltage or potential to said electrodes in order to excite parametrically at least some ions, in use, within said DC potential trapping profile, and to cause certain ions to be parametrically excited and axially ejected from said ion guide or ion trap, wherein said AC voltage or potential has a frequency σ which excludes the fundamental frequency ω of the at least some ions which are excited parametrically.
1 more element
A mass spectrometer comprising:
- a linear ion guide or an ion trap including;
- a plurality of electrodes;
- a DC voltage supply arranged and adapted to maintain a DC potential trapping profile along at least a portion of an axial length of said ion guide or ion trap in a first mode of operation;
- and
- an AC or RF voltage supply arranged and adapted to apply an AC voltage or potential to said electrodes in order to excite parametrically at least some ions, in use, within said DC potential trapping profile and to cause certain ions to be parametrically excited and axially ejected from said ion guide or ion trap, wherein said AC voltage or potential has a frequency σ which excludes the fundamental frequency ω of the at least some ions which are excited parametrically.
2 more elements
A method of guiding or trapping ions comprising:
- providing an ion guide or ion trap comprising a plurality of electrodes;
- maintaining a DC potential trapping profile along at least a portion of an axial length of said ion guide or ion trap in a first mode of operation;
- and
- applying an AC voltage or potential to said electrodes in order to excite parametrically ions within said DC potential trapping profile, wherein said AC voltage or potential has a frequency σ which excludes the fundamental frequency ω of ions within said ion guide or ion trap which are excited parametrically;
- and wherein applying said AC voltage or potential causes certain ions to be parametrically excited and axially ejected from said ion guide or ion trap.
2 more elements
Dependencies are inferred from the claim text.