Imaging mass spectrometer

Patent metadata

Field	Value
Publication number	US-10593533-B2
Application number	US-201615776704-A
Country	US
Kind code	B2
Filing date	Nov 16, 2016
Priority date	Nov 16, 2015
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

A time-of-flight mass spectrometer is disclosed comprising: an ion deflector ( 305 ) configured to deflect ions to different positions in a first array of positions at different times; a position sensitive ion detector ( 187 ); and ion optics ( 180 ) arranged and configured to guide ions from the first array of positions to the position sensitive detector ( 187 ) so as to map ions from the first array of positions to a second array of positions on the position sensitive detector ( 187 ); wherein the ion optics includes at least one ion mirror for reflecting the ions.

First claim

The invention claimed is:

1. A time-of-flight mass spectrometer comprising:
an ion deflector arranged to receive ions at different times and configured to deflect the ions received at different times to different respective positions in a first array of positions at said different times, wherein the ion deflector is configured to deflect the ions so that the ions exit the ion deflector along different axes in an array of parallel axes at different times;
a position sensitive ion detector comprising an array of separate detection regions arranged at different positions on the position sensitive detector; and
ion optics arranged and configured to guide ions from the first array of positions to the position sensitive detector so as to map ions from the first array of positions to a second array of positions on the position sensitive detector;
wherein the ion optics includes at least one ion mirror for reflecting the ions; and
wherein the time-of-flight mass spectrometer is configured to determine that ions received at different ones of said detection regions have originated from different positions in the first array of positions.

2. The spectrometer of claim 1 , wherein ions at any given position in the first array of positions are mapped to the same relative position in the second array of positions on the detector.

3. The spectrometer of claim 1 , wherein the ion deflector comprises at least one electrode and at least one voltage supply for applying voltages to said at least one electrode, and wherein the voltage supply is configured to vary the voltage applied to the at least one electrode with time so as to deflect the ions to different positions in said first array of positions at different times such that the ions are mapped to corresponding different positions in the second array of positions on the detector at different times.

4. The spectrometer of claim 3 , wherein the voltage supply is configured to vary the voltage applied to the at least one electrode with time so as to deflect all of the ions to a first position in said first array of positions at a first time and so as to deflect all of the ions to a second, different position in said first array of positions at a second, different time.

5. The spectrometer of claim 1 , wherein the ion deflector is configured to receive ions along a first axis, and to deflect ions with a velocity component orthogonal to the first axis so that the ions exit the ion deflector along a second axis that is substantially parallel to the first axis, wherein the second axis is displaced from the first axis by a distance that varies with time.

6. The spectrometer of claim 1 , wherein the ion deflector comprises at least one entrance electrode and at least one voltage source for deflecting the ions in a first direction, at any given time, and at least one downstream exit electrode and at least one voltage source for deflecting the same ions in a second, opposite direction at said given time.

7. The spectrometer of claim 6 , comprising one or more ion focusing member arranged between the at least one entrance electrode and the at least one exit electrode;
wherein the ion deflector is configured to deflect ions in a first dimension and the one or more ion focusing member is configured to focus ions in a second dimension orthogonal to the first dimension.

8. The spectrometer of claim 1 , further comprising an ion accelerator for pulsing the ions from said first array of positions into the ion optics and towards the detector, wherein an ion guide or ion trap is arranged upstream of the ion accelerator and is configured to release packets of ions to the ion accelerator, wherein the ion guide or ion trap and the ion accelerator are configured such that the releasing of packets of ions from the ion guide or ion trap is synchronized with the pulsing of ions from the ion accelerator towards the detector;
wherein the spectrometer is configured to provide a delay time between the release of each packet of ions from the ion guide or ion trap and the time at which these ions are pulsed from the ion accelerator towards the detector, and wherein the delay time is varied as a function of the mass to charge ratio or ion mobility of the ions released from the ion guide or ion trap.

9. The spectrometer of claim 8 , wherein an ion separation device, source of ions or ion filter is arranged upstream of said ion guide or ion trap for supplying ions of different mass to charge ratio or ion mobility to said ion guide or ion trap at different times; and/or
wherein the ion guide or ion trap comprises an ion filter or ion separator and is configured such that the mass to charge ratio or range of mass to charge ratios stored by the ion guide or ion trap, or the ion mobility or range of ion mobilities stored by the ion guide or ion trap, vary with time.

10. The spectrometer of claim 1 , comprising an ion separator arranged upstream of the ion deflector and configured to separate ions according to a physicochemical property, such as mass to charge ratio or ion mobility; and wherein the spectrometer is configured to control the ion deflector so as to deflect ions having different values of said physicochemical property to respective different positions in said first array of positions such that ions having said different values of said physicochemical property are guided to respective different positions in second array of positions at different times.

11. The spectrometer of claim 10 , comprising a controller configured to control the separator device to perform a plurality of ion separation cycles, during each of which ions are separated according to said physicochemical property, and to control the ion deflector to perform a corresponding plurality of ion deflection cycles, during each of which ions are deflected to said different positions within said first array of positions at different times; and wherein the ion deflection cycles are synchronized with the ion separation cycles.

12. The spectrometer of claim 1 , comprising an ion accelerator for pulsing the ions from said first array of positions into the ion optics and towards the detector, and wherein the spectrometer is configured to determine the flight times of the ions from the ion accelerator to the detector;
wherein the ion accelerator is configured to pulse ions towards the detector in a series of ion accelerator pulses, wherein the timings of the pulses are determined by an encoding sequence that varies the duration of the time interval between adjacent pulses as the series of pulses progresses; and wherein the spectrometer comprises a processor configured to use the timings of the pulses in the encoding sequence to determine which ion data detected at the detector relate to which ion accelerator pulse so as to resolve spectral data obtained from the different ion accelerator pulses.

13. The spectrometer of claim 1 , wherein the ion optics includes at least two ion mirrors for reflecting ions;
wherein said ion optics, including the at least two ion mirrors, are arranged and configured such that the ions are reflected by each of the mirrors and between the mirrors a plurality of times before reaching the detector; or
wherein the ion optics include at least one ion mirror for reflecting ions and at least one electrostatic or magnetic sector for receiving ions and guiding the ions into the at least one ion mirror; wherein the at least one ion mirror and at least one sector are configured such that the ions are transmitted from the at least one sector into each mirror a plurality of times such that the ions are reflected by said each ion mirror a plurality of times.

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Assignees

• Micromass Ltd
• Leco Corp

Inventors

• Hoyes John Brian
• Verenchikov Anatoly
• Yavor Mikhail
• Richardson Keith
• Wildgoose Jason

Classifications

• H01J49/061

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

• H01J49/406 Primary

  with multiple reflections · CPC title

• H01J49/062

  Ion guides (linear ion traps performing mass selection H01J49/4225, mass filters H01J49/421) · CPC title

• H01J49/0004

  Imaging particle spectrometry · CPC title

• H01J49/401

  characterised by orthogonal acceleration, e.g. focusing or selecting the ions, pusher electrode · CPC title