Multi-reflection mass spectrometer

Patent metadata

Field	Value
Publication number	US-2016005580-A1
Application number	US-201514853892-A
Country	US
Kind code	A1
Filing date	Sep 14, 2015
Priority date	Jan 27, 2012
Publication date	Jan 7, 2016
Grant date	—

Abstract

A multi-reflection mass spectrometer comprising two ion-optical mirrors, each mirror elongated generally along a drift direction (Y), each mirror opposing the other in an X direction and having a space therebetween, the X direction being orthogonal to Y; the mass spectrometer further comprising one or more compensation electrodes each electrode being located in or adjacent the space extending between the opposing mirrors; the compensation electrodes being configured and electrically biased in use so as to produce, in at least a portion of the space extending between the mirrors, an electrical potential offset which: (i) varies as a function of the distance along the drift length, and/or; (ii) has a different extent in the X direction as a function of the distance along the drift length. In a preferred embodiment the period of ion oscillation between the mirrors is not substantially constant along the whole of the drift length.

First claim

1 . (canceled)

2 . A multi-reflection mass spectrometer comprising two ion-optical mirrors, each mirror elongated generally along a drift direction (Y), each mirror opposing the other in an X direction and having a space therebetween, the X direction being orthogonal to the Y direction;
the spectrometer further comprising an ion injector located at one end of the ion-optical mirrors in the drift direction, arranged so that in use it injects ions such that they oscillate between the ion-optical mirrors, reflecting from one mirror to the other generally orthogonally to the drift direction a plurality of times, turning the ions within each mirror whilst the ions proceed along the drift direction Y; wherein a distance between subsequent points at which the ions turn in the Y-direction changes monotonously with Y during at least a part of the motion of the ions along the drift direction.

3 . The multi-reflection mass spectrometer of claim 1 in which the mass spectrometer further comprises one or more compensation electrodes each electrode being located in or adjacent the space extending between the opposing mirrors; wherein the compensation electrodes are, in use, electrically biased such that the distance between subsequent points at which the ions turn in the Y-direction changes monotonously with Y during at least a part of the motion of the ions along the drift direction.

4 . The multi-reflection mass spectrometer of claim 1 in which both mirrors are elongated linearly along the drift direction and are arranged an equal distance apart in the X direction.

5 . The multi-reflection mass spectrometer of claim 1 in which both mirrors are elongated non-linearly along the drift direction and are arranged to have an equal gap between them.

6 . The multi-reflection mass spectrometer of claim 1 in which a period of ion oscillation decreases along at least a portion of the drift length as ions proceed away from the ion injector.

7 . The multi-reflection mass spectrometer of claim 1 in which the ions are turned around after passing along the drift length and proceed back along the drift length towards the ion injector.

8 . The multi-reflection mass spectrometer of claim 2 in which the one or more compensation electrodes comprises a pair of compensation electrodes, each of which is disposed either side of a space between the mirrors and has a surface having a polynomial profile in the X-Y plane such that the surfaces extend towards each mirror a greater distance in regions near one or both the ends of the mirrors than in a central region between the ends.

9 . The multi-reflection mass spectrometer of claim 2 in which the one or more compensation electrodes comprises a pair of compensation electrodes, each of which is disposed either side of a space between the mirrors and has a surface having a polynomial profile in an X-Y plane such that the surfaces extend towards each mirror a lesser distance in regions near one or both ends of the mirrors than in a central region between the ends.

10 . The multi-reflection mass spectrometer of claim 2 in which the compensation electrodes comprise a plurality of tubes or compartments located at least partially in the space extending between the opposing mirrors.

11 . The multi-reflection mass spectrometer of claim 2 in which the one or more compensation electrodes are, in use, electrically biased so as to produce, in at least a portion of the space between the mirrors, an electrical potential offset which varies as a function of the distance along the drift length.

12 . The multi-reflection mass spectrometer of claim 1 further comprising a detector located in a region adjacent the ion injector.

13 . The multi-reflection mass spectrometer of claim 1 in further comprising one or more lenses or diaphragms located in a space between the mirrors so as to affect a phase-space volume of ions within the mass spectrometer.

14 . The multi-reflection mass spectrometer of claim 1 in which, in use, the ion injector injects ions from one end of the mirrors into a space between the mirrors at an inclination angle in an X-Y plane such that ions are reflected from one opposing mirror to the other a plurality of times whilst drifting along a drift direction away from the ion injector so as to follow a generally zigzag path within the mass spectrometer.

15 . The multi-reflection mass spectrometer of claim 13 in which a motion of ions along the drift direction is opposed by electric field components resulting from one or more electrically biased compensation electrodes.

16 . The multi-reflection mass spectrometer of claim 14 in which the said electric field components cause the ions to reverse their direction and travel back towards the ion injector.

17 . The multi-reflection mass spectrometer of claim 15 in which at least some of the ions impinge upon a detector located in a region adjacent the ion injector.

18 . The multi-reflection mass spectrometer of claim 16 wherein the detector has a detection surface which is arranged parallel to the drift direction Y.

19 . The multi-reflection mass spectrometer of claim 1 wherein both mirrors are implemented as a pair of printed-circuit boards arranged with their printed surfaces parallel to and facing each other.

20 . The multi-reflection mass spectrometer of claim 2 wherein both compensation electrodes are implemented as a pair of printed-circuit boards arranged with their printed surfaces parallel to and facing each other.

21 . The multi-reflection mass spectrometer of claim 1 , wherein the multi-reflection mass spectrometer is a time-of-flight multi-reflection mass spectrometer.

22 . An electrostatic trap mass spectrometer comprising two or more multi-reflection mass spectrometers, wherein each multi-reflection mass spectrometer comprises two ion-optical mirrors, each mirror elongated generally along a drift direction (Y), each mirror opposing the other in an X direction and having a space therebetween, the X direction being orthogonal to Y;
the mass spectrometer further comprising an ion injector located at one end of the ion-optical mirrors in the drift direction, arranged so that in use it injects ions such that they oscillate between the ion-optical mirrors, reflecting from one mirror to the other generally orthogonally to the drift direction a plurality of times, turning the ions within each mirror whilst the ions proceed along the drift direction Y; wherein the distance between subsequent points at which the ions turn in the Y-direction changes monotonously with Y during at least a part of the motion of the ions along the drift direction.

23 . The electrostatic trap mass spectrometer of claim 21 comprising two multi-reflection mass spectrometers arranged end to end symmetrically about an X axis such that their respective drift directions are collinear, the multi-reflection mass spectrometers thereby defining a volume within which, in use, ions follow a closed path with isochronous properties in both the drift directions and in an ion flight direction.

24 . A composite mass spectrometer comprising two or more multi-reflection mass spectrometers wherein each multi-reflection mass spectrometer comprises two ion-optical mirrors, each mirror elongated generally along a drift direction (Y), each mirror opposing the other in an X direction and having a space therebetween, the X direction being orthogonal to Y;
the mass spectrometer further comprising an ion

Assignees

• Thermo Fisher Scient Bremen

Inventors

• Grinfeld Dmitry
• Makarov Alexander

Classifications

• H01J49/4245

  Electrostatic ion traps (H01J49/422 takes precedence) · CPC title

• H01J49/0031

  Step by step routines describing the use of the apparatus (H01J49/0081 takes precedence) · CPC title

• H01J49/004

  Combinations of spectrometers, tandem spectrometers, e.g. MS/MS, MSn · CPC title

• H01J49/06 Primary

  Electron- or ion-optical arrangements · CPC title

• H01J49/406 Primary

  with multiple reflections · CPC title