Dynamic multipole Kingdon ion trap

1. A linear ion trap, comprising:

a. a plurality of elongate electrodes (“outer electrodes”), each having a longitudinal axis that is aligned with a central longitudinal axis, the plurality of elongate electrodes being spaced apart from one another and disposed about that central longitudinal axis to form a quadrupole;

b. an elongate electrode (“central electrode”) that is aligned with and disposed along the central longitudinal axis and positioned between the plurality of elongate electrodes that form a quadrupole; and

c. circuitry coupled to the outer electrodes suitable for driving the central electrode and the plurality of outer electrodes so as to selectively trap ions within a region defined between the central electrode and the outer electrodes, the ions around the central electrode, by applying

(i) to the outer electrodes an RF-varying potential such that each pair of outer electrodes disposed opposite one another vis-a-vis the central longitudinal axis is at an RF-varying potential to each other pair of outer electrodes disposed opposite one another vis-a-vis that axis, and

(ii) to the central electrode at least one of a DC voltage and an RF-varying voltage.

2. The ion trap of claim 1 , comprising at least one of an ion inlet and an ion outlet.

3. The ion trap of claim 2 , wherein at least one of the ion inlet and the ion outlet are grid lenses.

4. The ion trap of claim 3 , wherein the circuitry is coupled to at least one of said grid lenses and applies thereto any of a DC potential and an RF-varying potential.

5. The ion trap of claim 1 , wherein each outer electrode of each pair of outer electrodes disposed opposite one another vis-a-vis the central longitudinal axis are at the same potential as one another.

6. The ion trap of claim 1 , in which the one or more of the outer electrodes are rod-shaped.

7. The ion trap of claim 1 , in which the inner electrode comprises a wire.

8. A mass spectrometer comprising one or more linear ion traps, each comprising:

a. a plurality of elongate electrodes (“outer electrodes”), each having a longitudinal axis that is aligned with a central longitudinal axis, the plurality of elongate electrodes being spaced apart from one another and disposed about that central longitudinal axis to form a quadrupole;

b. an elongate electrode (“central electrode”) that is aligned with and disposed along the central longitudinal axis and positioned between the plurality of elongate electrodes that form a quadrupole;

c. circuitry coupled to the outer electrodes suitable for driving the central electrode and the plurality of outer electrodes so as to selectively trap of ions within a region defined between the central electrode and the outer electrodes, the ions around the central electrode; and

d. wherein the circuitry can selectively trap such ions by applying

(i) to the outer electrodes an RF-varying potential such that each pair of outer electrodes disposed opposite one another vis-a-vis the central longitudinal axis is at an RF-varying potential to each other pair of outer electrodes disposed opposite one another vis-a-vis that axis, and

(ii) to the central electrode at least one of a DC voltage and an RF-varying voltage.

9. A method of trapping ions in a linear ion trap, comprising:

a. providing a plurality of elongate electrodes (“outer electrodes”), each having a longitudinal axis that is aligned with a central longitudinal axis, the plurality of elongate electrodes being spaced apart from one another and disposed about that central longitudinal axis to form a quadrupole;

b. providing an elongate electrode (“central electrode”) that is aligned with and disposed along the central longitudinal axis and positioned between the plurality of elongate electrodes that form a quadrupole;

c. driving the central electrode and the plurality of outer electrodes so as to selectively trap of ions within a region defined between the central electrode and the outer electrodes, the ions around the central electrode; and

d. wherein the driving step is effected by applying

(i) to the outer electrodes an RF-varying potential such that each pair of outer electrodes disposed opposite one another vis-a-vis the central longitudinal axis is at an RF-varying potential to each other pair of outer electrodes disposed opposite one another vis-a-vis that axis, and

(ii) to the central electrode at least one of a DC voltage and an RF-varying voltage.