Systems and methods for coupling a laser beam to a mass spectrometer

Patent metadata

Field	Value
Publication number	US-9892903-B1
Application number	US-201615389377-A
Country	US
Kind code	B1
Filing date	Dec 22, 2016
Priority date	Dec 22, 2016
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

A mass spectrometry system includes a laser source, a trapping volume, first and second beam deflectors, and a deflector controller. The first and second beam deflectors are arranged on a path from the laser source to the trapping volume. The first beam deflector is configured to oscillate in a first direction at a first frequency and the second beam deflector configured to oscillate in a second direction orthogonal to the first direction at a second frequency. The deflector controller is configured to scan a scanned area within the trapping volume with the laser by controlling the oscillation of the first and second beam deflectors to cause ions trapped within the trapping volume to fragment into fragment ions. The scanned area has a first dimension defined by the oscillation in first direction and a second dimension defined by the oscillation in the second direction.

First claim

What is claimed is:

1. A mass spectrometry system comprising:
a laser source;
a trapping volume;
first and second beam deflectors arranged on a path from the laser source to the trapping volume, the first beam deflector configured to oscillate in a first direction at a first frequency and the second beam deflector configured to oscillate in a second direction orthogonal to the first direction at a second frequency;
a deflector controller configured to:
scan a scanned area within the trapping volume with the laser by controlling the oscillation of the first and second beam deflectors to cause ions trapped within the trapping volume to become excited, the scanned area having a first dimension defined by the oscillation in first direction and a second dimension defined by the oscillation in the second direction.

2. The mass spectrometry system of claim 1 wherein the first and second beam deflectors are mirror galvanometers.

3. The mass spectrometry system of claim 1 wherein the first and second beam deflectors are acousto-optic modulators.

4. The mass spectrometry system of claim 1 wherein the second frequency is a multiple of the first frequency.

5. The mass spectrometry system of claim 4 wherein the multiple is an integer multiple.

6. The mass spectrometry system of claim 4 wherein the second frequency is not less than the first frequency times the ratio of the first dimension to a beam width.

7. The mass spectrometry system of claim 1 wherein the laser source is a pulsed laser source with a pulse frequency higher than the second frequency.

8. The mass spectrometry system of claim 7 wherein, the pulse frequency is not less than the second frequency times the ratio of the second dimension to a beam width.

9. The mass spectrometry system of claim 1 further comprising an ion source for producing the ions, and ion optics for moving the ions from the ion source to the trapping volume.

10. The mass spectrometry system of claim 1 further comprising a mass analyzer configured to determine the mass to charge ratio of the ions.

11. A method of analyzing ion fragments, comprising: trapping ions within a trapping volume; sweeping an area of the trapping volume with a laser by oscillating first and second beam deflectors to excite the ions, the first beam deflector configured to oscillate in a first direction at a first frequency and the second beam deflector configured to oscillate in a second direction orthogonal to the first direction at a second frequency; fragmenting the excited ions within the trapping volume to produce ion fragments; determining a mass-to-charge ratio for the ion fragments.

12. The method of claim 11 wherein the first and second beam deflectors are mirror galvanometers.

13. The method of claim 11 wherein the first and second beam deflectors are acousto-optic modulators.

14. The method of claim 11 wherein the second frequency is a multiple of the first frequency.

15. The method of claim 14 wherein the multiple is an integer multiple.

16. The method of claim 14 wherein the second frequency is not less than the first frequency times the ratio of the first dimension to a beam width.

17. The method of claim 11 wherein the laser is a pulsed laser with a pulse frequency higher than the second frequency.

18. The method of claim 17 wherein the pulse frequency is not less than the second frequency times the ratio of the second dimension to a beam width.

19. The method of claim 11 further comprising producing ions from a sample in an ion source, and guiding the ions from the ion source to the trapping volume using ion optics.

Assignees

• Thermo Finnigan Llc

Inventors

• Canterbury Jesse D

Classifications

• H01J49/427 Primary

  Ejection and selection methods · CPC title

• H01J49/061

  Ion deflecting means, e.g. ion gates · CPC title

• H01J49/26 Primary

  Mass spectrometers or separator tubes · CPC title

• H01J49/0059 Primary

  by a photon beam, photo-dissociation · CPC title