High resolution multi-reflection time-of-flight mass analyser

Patent metadata

Field	Value
Publication number	US-12469691-B2
Application number	US-202318118461-A
Country	US
Kind code	B2
Filing date	Mar 7, 2023
Priority date	Mar 8, 2022
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

Systems, methods, and computer-readable media described provide multi-reflection time-of-flight analyser (e.g. of a type in which the ion beam is allowed to spread out relatively broadly) and methods for use in a zoom mode, in which time-of-flight perturbations induced by reflections at the deflector are cancelled out or removed, such that they do not give rise to a significant increase in the arrival time spread of ions at the detector. This accordingly facilitates high resolution operation of the analyser in the zoom mode. Furthermore, this is done in a way which allows the analyser to remain drift focused, which in turn means that the analyser can be straightforwardly and seamlessly switched between its normal mode of operation and the zoom mode of operation.

First claim

The invention claimed is:

1 . A method of operating a multi-reflection time-of-flight mass analyser that comprises:
two ion mirrors spaced apart and opposing each other in a first direction X, each mirror elongated generally along a drift direction Y between a first end and a second end, the drift direction Y being orthogonal to the first direction X; an ion injector for injecting ions into a space between the ion mirrors, the ion injector located in proximity with the first end of the ion mirrors; a detector for detecting ions after they have completed a plurality of reflections between the ion mirrors, the detector located in proximity with the first end of the ion mirrors; and a deflector located in proximity with the first end of the ion mirrors; the method comprising:
(i) injecting ions from the ion injector into the space between the ion mirrors, wherein the ions complete a first cycle in which the ions follow a zigzag ion path having plural reflections between the ion mirrors in the direction X whilst: (a) drifting along the drift direction Y from the deflector towards the second end of the ion mirrors, (b) reversing drift direction velocity in proximity with the second end of the ion mirrors, and (c) drifting back along the drift direction Y to the deflector;
(ii) using the deflector to reverse the drift direction velocity of the ions such that the ions are caused to complete a further cycle in which the ions follow a zigzag ion path having plural reflections between the ion mirrors in the direction X whilst: (a) drifting along the drift direction Y from the deflector towards the second end of the ion mirrors, (b) reversing drift direction velocity in proximity with the second end of the ion mirrors, and (c) drifting back along the drift direction Y to the deflector;
(iii) repeating step (ii) one or more times; and then
(iv) causing the ions to travel from the deflector to the detector for detection;
wherein the method comprises causing the ions to travel from the deflector to the detector for detection only after the ions have completed in total an odd number of cycles.

2 . The method of claim 1 , wherein the deflector comprises one or more trapezoid shaped or prism-like electrodes arranged adjacent to the ion beam.

3 . The method of claim 1 , wherein the method comprises causing the ions to travel from the deflector to the detector for detection only after the drift direction velocity of the ions has been reversed by the deflector in total an even number of times.

4 . The method of claim 1 , wherein the method comprises preventing ions that have completed in total an even number of cycles from travelling from the deflector to the detector.

5 . The method of claim 1 , wherein the analyser comprises a drift focusing lens arranged within the deflector, and wherein the method comprises:
applying a first voltage to the drift focusing lens when the ions are injected into the space between the ion mirrors; and applying a second different voltage to the drift focusing lens when the deflector is used to reverse the drift direction velocity of the ions.

6 . A method of operating a multi-reflection time-of-flight mass analyser that comprises:
two ion mirrors spaced apart and opposing each other in a first direction X, each mirror elongated generally along a drift direction Y between a first end and a second end, the drift direction Y being orthogonal to the first direction X; an ion injector for injecting ions into a space between the ion mirrors, the ion injector located in proximity with the first end of the ion mirrors; a detector for detecting ions after they have completed a plurality of reflections between the ion mirrors, the detector located in proximity with the first end of the ion mirrors; a deflector located in proximity with the first end of the ion mirrors; and a drift focusing lens arranged within the deflector; the method comprising:
(i) injecting ions from the ion injector into the space between the ion mirrors, wherein the ions complete a first cycle in which the ions follow a zigzag ion path having plural reflections between the ion mirrors in the direction X whilst: (a) drifting along the drift direction Y from the deflector towards the second end of the ion mirrors, (b) reversing drift direction velocity in proximity with the second end of the ion mirrors, and (c) drifting back along the drift direction Y to the deflector;
(ii) using the deflector to reverse the drift direction velocity of the ions such that the ions are caused to complete a further cycle in which the ions follow a zigzag ion path having plural reflections between the ion mirrors in the direction X whilst: (a) drifting along the drift direction Y from the deflector towards the second end of the ion mirrors, (b) reversing drift direction velocity in proximity with the second end of the ion mirrors, and (c) drifting back along the drift direction Y to the deflector;
(iii) causing the ions to travel from the deflector to the detector for detection;
wherein the method further comprises:
applying a first voltage to the drift focusing lens when the ions are injected into the space between the ion mirrors; and
applying a second different voltage to the drift focusing lens when the deflector is used to reverse the drift direction velocity of the ions.

7 . The method of claim 6 , further comprising applying the second voltage or a third different voltage to the drift focusing lens when the ions are caused to travel from the deflector to the detector for detection.

8 . The method of claim 1 , wherein (ii) using the deflector to reverse the drift direction velocity of the ions comprises applying a voltage to the deflector that causes ions to exit the deflector with a drift direction velocity opposite to the drift direction velocity with which the ions entered the deflector.

9 . The method of claim 1 , wherein (ii) using the deflector to reverse the drift direction velocity of the ions comprises applying a voltage to the deflector that causes the drift direction velocity of the ions to be reduced to approximately zero, such that ions exit the deflector in the first X direction and are reflected from an ion mirror back into the deflector, whereupon the deflector acts to change the drift direction velocity of the ions from zero to a drift direction velocity opposite to the drift direction velocity with which the ions originally entered the deflector.

10 . A method of operating a multi-reflection time-of-flight mass analyser that comprises:
two ion mirrors spaced apart and opposing each other in a first direction X, each mirror elongated generally along a drift direction Y between a first end and a second end, the drift direction Y being orthogonal to the first direction X; an ion injector for injecting ions into a space between the ion mirrors, the ion injector located in proximity with the first end of the ion mirrors; a detector for detecting ions after they have completed a plurality of reflections between the ion mirrors, the detector located in proximity with the first end of the ion mirrors; and a deflector located in proximity with the first end of the ion mirrors; the method comprising:
(i) injecting ions from the ion injector into the space between the ion mirrors, wherein the ions complete a first cycle in which the ions follow a zigzag ion path having plural reflections between the ion mirrors in the direction X whilst: (a) drifting along the drift direction Y from the deflector towards the second end of the ion mirrors, (b) reversing drift direction velocity in proximity with the second end of the ion mirrors, and (c) drifting back along the drift direction Y to the deflector;
(ii)

Assignees

• Thermo Fisher Scient Bremen Gmbh

Inventors

• Stewart Hamish
• Grinfeld Dmitry
• Hagedorn Bernd
• Ostermann Robert

Classifications

• H01J49/061

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

• H01J49/0031

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

• H01J49/406 Primary

  with multiple reflections · CPC title