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US 8,946,623 B2Granted
Introduction of ions into kingdon ion traps
AssigneeBruker Daltonik GmbH
InventorsClaus Köster, Jochen Franzen
Life of this patent
Estimating the term…
Abstract
The geometry of a Kingdon ion trap, in which harmonic ion oscillation in a potential well in a longitudinal direction is completely decoupled from ion oscillation in a direction transverse to the longitudinal direction, is arranged so that the oscillating ions introduced through the entrance tube cannot return to the entrance tube until they have performed several longitudinal oscillations during which time heavier ions can be introduced into the trap. In one embodiment, ions enter the trap via an entrance tube extending through, but electrically insulated from, one of the Kingdon trap housing electrodes and located outside the minimum of the potential well in the longitudinal direction.
Claims17
A Kingdon ion trap comprising:
- housing electrodes extending in a longitudinal direction;
- at least one inner electrode spaced from the housing electrodes in a direction transverse to the longitudinal direction, the housing electrodes and the at least one inner electrode being shaped so that ions introduced into the trap can oscillate harmonically in a potential well in the longitudinal direction and independently oscillate in the transverse direction when a DC electric field is established between the housing electrodes and the at least one inner electrode;
- and
- a hole that extends through one of the housing electrodes and allows ions to enter the ion trap wherein the housing electrodes have an inside diameter and a length and wherein a ratio of the length to the inside diameter is selected so that ions introduced into the trap through the hole oscillate in the longitudinal direction in a manner that the ions only return to the location of the hole after at least five longitudinal oscillations, thereby enabling heavier ions to enter the ion trap through the hole before lighter ions exit the ion trap through the hole.
1 more element
A method for storing ions, comprising:
- (a) providing a Kingdon ion trap having housing electrodes extending in a longitudinal direction, at least one inner electrode spaced from the housing electrodes in a direction transverse to the longitudinal direction, the housing electrodes and the at least one inner electrode being shaped so that ions introduced into the trap can oscillate harmonically in a potential well in the longitudinal direction and independently oscillate in the transverse direction when a DC electric field is established between the housing electrodes and the at least one inner electrode and a hole that extends through one of the housing electrodes and allows ions to enter the ion trap,
- wherein the housing electrodes have an inside diameter and a length and wherein a ratio of the length to the inside diameter is selected so that ions introduced into the trap through the hole oscillate in the longitudinal direction in a manner that the ions only return to the location of the hole after at least five longitudinal oscillations, thereby enabling heavier ions to enter the ion trap through the hole before lighter ions exit the ion trap through the hole;
- (b) generating an ion cloud;
- and
- (c) transferring ions from the ion cloud through the hole into the Kingdon trap.
2 more elements
A mass spectrometer comprising:
- an ion source for producing ions;
- a Paul ion trap for receiving the ions;
- and
- a Kingdon ion trap for receiving ions from the Paul ion trap, the Kingdon ion trap having, housing electrodes extending in a longitudinal direction,
- at least one inner electrode spaced from the housing electrodes in a direction transverse to the longitudinal direction, the housing electrodes and the at least one inner electrode being shaped so that ions introduced into the trap can oscillate harmonically in a potential well in the longitudinal direction and independently oscillate in the transverse direction when a DC electric field is established between the housing electrodes and the at least one inner electrode and a hole that extends through one of the housing electrodes and allows ions to enter the ion trap,
- wherein the housing electrodes have an inside diameter and a length and wherein a ratio of the length to the inside diameter is selected so that ions introduced into the trap through the hole oscillate in the longitudinal direction in a manner that the ions only return to the location of the hole after at least five longitudinal oscillations, thereby enabling heavier ions to enter the ion trap through the hole before lighter ions exit the ion trap through the hole.
3 more elements
Dependencies are inferred from the claim text.