MASS SPECTROMETER WITH PRECISELY ALIGNED ION OPTIC ASSEMBLIES

• US 20130015347A1
• Filed: 02/06/2012
• Published: 01/17/2013
• Est. Priority Date: 07/14/2011
• Status: Active Grant

• Current Assignee: Bruker Daltonics GmbH and Co KG (Bruker Corporation)
• Original Assignee: Bruker Daltonics, Inc. (Bruker Corporation)
• Inventors: STEINER, Urs
• Granted Patent: US 8,618,473 B2
• Time in Patent Office: Days
• US Class Current: 250/288
• CPC Class Codes: H01J 49/063 Multipole ion guides, e.g. quadrupoles, hexapoles
• CPC Class Codes: H01J 49/068 Mounting, supporting, spacing, or insulating electrodes

Abstract

A mass spectrometer has a manifold and at least one ion optical assembly that is composed of a support and electrodes attached to the support. The support is aligned to at least one reference surface machined integrally with the manifold such that the number of interfaces between the reference surface of the manifold and the electrodes is minimized. With such a design the positional and/or alignment precision of ion optical assemblies in a mass spectrometer can be improved.

Claims

1. A mass spectrometer comprising a manifold and at least one multipole ion optical assembly, comprising:

the multipole ion optical assembly having a support with two sides and a plurality of electrodes, all electrodes being attached to one side of said support;

at least one reference surface that is integrally machined with the manifold; and

a mechanism that aligns the support to the at least one reference surface such that a number of interfaces between the reference surface of the manifold and the electrodes is minimized.

2. The mass spectrometer according to claim 1, wherein the manifold is a single machined work piece.

3. The mass spectrometer according to claim 1, wherein the reference surface is a surface of a recess machined integrally with the manifold.

4. The mass spectrometer according to claim 1, wherein the reference surface is a substantially planar surface at one of a post, step and plateau machined integrally with the manifold.

5. The mass spectrometer according to claim 1, wherein the manifold comprises walls and a ground plate forming part of a housing of the mass spectrometer.

6. The mass spectrometer according to claim 5, wherein the walls of the housing have a height of less than 8 centimeters.

7. The mass spectrometer according to claim 6, wherein the manifold has a volume of less than 8,000 cubic centimeters.

8. The mass spectrometer according to claim 5, wherein the reference surface is a substantially planar surface at one of a step and plateau machined integrally with the walls.

9. The mass spectrometer according to claim 1, wherein the reference surface is substantially planar and comprises at least one pin protruding therefrom, and wherein the support comprises corresponding recesses or openings for aligning the support in directions essentially parallel to the reference surface such that the ion optical assembly is aligned in more than one dimension.

10. The mass spectrometer according to claim 1, wherein the ion optical assembly is an RF multipole electrode assembly, wherein the support is a substantially planar printed circuit board having two surfaces, and wherein all the electrodes are mounted on one surface of the printed circuit board and that one surface is aligned to the reference surface.

11. The mass spectrometer according to claim 1, wherein the reference surface is substantially planar, wherein the ion optical assembly is a quadrupole mass filter having four rods and the support comprises insulating rings attached to and holding the rods, and wherein the rings have at least one common straight edge at an outer periphery for aligning the quadrupole mass filter to the reference surface.

12. The mass spectrometer according to claim 11, wherein the insulating rings are ceramic rings.

13. The mass spectrometer according to claim 1, wherein the reference surface is substantially planar, wherein the ion optical assembly is a RF multipole rod assembly and the support comprises insulating rings attached to and holding the rods, and wherein the rings have at least one common straight edge at an outer periphery being aligned to the reference surface.

14. The mass spectrometer according to claim 1, wherein the support is rigidly attached to the at least one reference surface by one of:

adhesion, screwing and clamping.

15. The mass spectrometer according to claim 1, wherein the shape accuracy and the position accuracy of the reference surface is better than ten micrometers each.

16. The mass spectrometer according to claim 1, wherein a position accuracy of the ion optical assembly is better than hundred micrometers.

17. A mass spectrometer comprising a manifold and at least one multipole ion optical assembly, comprising:

the multipole ion optical assembly having a support with an adjustment surface, a plurality of electrodes, all of which are aligned to said adjustment surface;

a reference surface machined integrally with the manifold; and

a mechanism that aligns the adjustment surface to the reference surface such that a number of interfaces between the reference surface and the adjustment surface is minimized.

18. The mass spectrometer according to claim 17, wherein the adjustment surface is machined at the support.

19. The mass spectrometer according to claim 17, wherein the support is one of an insulating ring and a circuit board.

20. The mass spectrometer according to claim 17, wherein the reference surface and the adjustment surface contact each other over a surface area.