Ion kinetic energy measuring device

Abstract

The application discloses an ion kinetic energy measuring device, which comprises a grid ground electrode, a grid deceleration electrode, a deflection electrode, an ion detection electrode, a direct current high-voltage power supply and a current measuring meter. In some specific scenarios such as ion soft landing preparation and ion optical modulation, an accurate ion kinetic energy detection means is needed. The application designs a novel ion kinetic energy detection device, which combines the electric field deceleration and the deflection plate in a skillful way, and can realize the on-line ion kinetic energy detection without blocking the ion path. The application is an innovative ion kinetic energy measuring technology, and has a wide application prospect in the fields of mass spectrum soft landing preparation and ion optical modulation.

Description

Technical Field

[0001] This invention relates to the field of instrumental analysis technology, and in particular to an ion kinetic energy measurement device for preparing mass spectrometers. Background Technology

[0002] Preparative mass spectrometry (pMS) is a technique that uses mass spectrometry as a separation method to precisely screen and prepare ions with specific mass-to-charge ratios (m / z) with high purity. In particular, the ion soft-landing technique (deposition energy <100 eV), developed in recent decades, can maintain the integrity of molecular structure and function during deposition, achieving highly selective, high-purity, and high-fidelity preparation of target molecules under high vacuum conditions. Since the ion deposition energy is related to the structure and function of the prepared molecules, developing an online, accurate ion kinetic energy measurement technique that does not affect the ion optical pathway is crucial.

[0003] A search of patents and papers revealed the following relevant patent for ion kinetic energy measurement: ShanghaiTech University applied for and published a high-energy, high-resolution composite electron-ion velocity imaging device on December 2, 2020. This device includes a gas sample introduction system, an analysis chamber, and a molecular beam trapping chamber. The gas sample introduction system injects a target gas sample into a high-vacuum environment in the form of an ultrasonic molecular beam and transmits it to the analysis chamber. The analysis chamber provides the high-vacuum environment required for the target gas sample to react with light, generating electrons and ions. An electric field distribution is set to control the trajectory of electrons and / or ions, ultimately obtaining the initial three-dimensional momentum distribution of electrons or ions. However, this patent primarily focuses on ion kinetic energy measurement in molecular reaction dynamics and is not a general online energy measurement technology. Summary of the Invention

[0004] This invention presents a novel ion kinetic energy detection device that can detect ion kinetic energy online by cleverly combining electric field deceleration with a deflection plate.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] An ion kinetic energy measuring device includes a grid ground electrode, a grid deceleration electrode, a deflection electrode, an ion detection electrode, a first DC high voltage power supply, a second DC high voltage power supply, and a current meter.

[0007] The X direction is to the right, and the Y direction is upward.

[0008] The ion kinetic energy measuring device is provided from left to right with a grid ground electrode, a grid deceleration electrode, a deflection electrode, and an ion detection electrode. Both the grid ground electrode and the grid deceleration electrode are flat plate structures with a circular through-hole in the center, and a metal grid parallel to the surface of the plate is installed on the through-hole. The grid ground electrode is connected to ground potential or grounded via a wire. The grid deceleration electrode is connected to a first DC high-voltage power supply via a wire. The through-holes of the grid ground electrode and the grid deceleration electrode are placed coaxially, spaced apart, and parallel. The deflection electrode and the ion detection electrode are both rectangular flat plate structures, symmetrically placed on both sides of the central axis of the through-holes of the grid ground electrode and the grid deceleration electrode, and are parallel and spaced apart. The deflection electrode is connected to a second DC high-voltage power supply via a wire. The ion detection electrode is connected to a current meter via a wire.

[0009] Furthermore, during operation, a scanning voltage Vr is applied to the grid deceleration electrode through the first DC high-voltage power supply, thereby tuning the electric field between the grid ground electrode and the grid deceleration electrode, and thus controlling the advance of ions of different energies. A voltage is applied to the deflection electrode through the second DC high-voltage power supply, deflecting the incoming ions to the detection electrode and recording the ion flow I through a current meter. The ion flow I obtained by recording the change of the scanning voltage Vr, i.e., dI and dVr, is recorded by the detection electrode. With Vr as the x-axis and the absolute value of dI / dVr as the y-axis, a curve of Vr - |dI / dVr| can be plotted. The value of the x-axis corresponding to the maximum value of the curve on the y-axis is the average kinetic energy of the ions. The value corresponding to the half-peak width obtained after Gaussian fitting of the curve is the ion energy width.

[0010] Furthermore, the ground electrode and the deceleration electrode are made of stainless steel or a material with a conductive coating on the surface; the shape of the ground electrode and the deceleration electrode can be annular, rectangular or other polygonal plate structure.

[0011] Furthermore, the first and second DC high-voltage power supplies are precision DC power supplies; the current measuring instrument is a picoampere galvanometer.

[0012] Furthermore, the ion kinetic energy measuring device can be used as a unit module for measuring ion beam current inside instruments such as mass spectrometers, or for the precise measurement of ion energy in ion soft deposition devices.

[0013] This invention is an innovative ion kinetic energy measurement technology. By cleverly combining electric field deceleration with a deflection plate, it enables online ion kinetic energy detection without obstructing the ion pathway. It has broad application prospects in fields such as mass spectrometry soft-landing preparation and ion optical modulation. Attached Figure Description

[0014] The accompanying drawings further illustrate the present invention, but the content of the drawings does not constitute any limitation on the present invention.

[0015] Figure 1 This is a schematic diagram of the overall structure of an ion kinetic energy measuring device according to one embodiment of the present invention;

[0016] Figure 2 This is a graph showing the change of current with scanning voltage in one embodiment of the present invention. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0021] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0022] Example

[0023] An ion kinetic energy measuring device according to this embodiment includes a grid ground electrode 2, a grid deceleration electrode 9, a deflection electrode 5, an ion detection electrode 7, a first DC high voltage power supply 3, a second DC high voltage power supply 4, and a current meter 8.

[0024] The X direction is to the right, and the Y direction is upward.

[0025] The ion kinetic energy measuring device is provided from left to right with a grid ground electrode 2, a grid deceleration electrode 9, a deflection electrode 5, and an ion detection electrode 7. The grid ground electrode 2 and the grid deceleration electrode 9 are both flat plate structures with a circular through hole in the middle, and a metal grid parallel to the surface of the flat plate is provided on the through hole in the middle. The grid ground electrode 2 is connected to the ground potential 10 or grounded through a wire. The grid deceleration electrode 9 is connected to the first DC high voltage power supply 3 through a wire. The through holes in the grid ground electrode 2 and the grid deceleration electrode 9 are placed coaxially, spaced apart, and parallel. The deflection electrode 5 and the ion detection electrode 7 are both rectangular flat plate structures, symmetrically placed on both sides of the central axis of the through holes of the grid ground electrode 2 and the grid deceleration electrode 9, and placed parallel to each other and spaced apart. The deflection electrode 5 is connected to the second DC high voltage power supply 4 through a wire. The ion detection electrode 7 is connected to the current meter 8 through a wire.

[0026] Furthermore, during operation, a scanning voltage Vr is applied to the grid deceleration electrode 9 through the first DC high-voltage power supply 3, thereby tuning the electric field between the grid ground electrode 2 and the grid deceleration electrode 9, and thus controlling the advance of the test ions 1 with different energies; a voltage is applied to the deflection electrode 5 through the second DC high-voltage power supply 4, deflecting the incoming test ions to the detection electrode 7 and recording the ion flow I through the current meter 8; the ion flow I obtained by recording the change of the scanning voltage Vr by the detection electrode, i.e., dI and dVr; with Vr as the x-axis and the absolute value of dI / dVr as the y-axis, the curve Vr-|dI / dVr| can be plotted, the maximum value of the curve on the y-axis corresponds to the value on the x-axis which is the average kinetic energy of the ion, and the value corresponding to the half-peak width of the Gaussian fit of the curve is the ion energy width.

[0027] Furthermore, the ground electrode 2 and the deceleration electrode 9 are made of stainless steel or a material with a conductive coating on the surface; the shape of the ground electrode 2 and the deceleration electrode 9 can be annular, rectangular or other polygonal flat plate structure.

[0028] Preferably, the ground electrode 2 and the deceleration electrode 9 are made of 316L stainless steel; the ground electrode 2 and the deceleration electrode 9 are circular in shape.

[0029] Furthermore, the first DC high-voltage power supply 3 and the second DC high-voltage power supply 4 are high-precision DC power supplies; the current measuring meter 8 is a high-precision picoampere galvanometer.

[0030] Preferably, the first DC high-voltage power supply 3 and the second DC high-voltage power supply 4 are selected from Spellman MPS series power modules, and the ammeter is a Keithley Piman ammeter.

[0031] Furthermore, the ion kinetic energy measurement device can be used as a unit module for measuring ion beam currents within instruments such as mass spectrometers, or for the precise measurement of ion energy in ion soft deposition devices.

[0032] In practical operation, for ions with a kinetic energy of approximately 20 eV, the voltage scanning range of the first DC high-voltage power supply 3 is 0–30 V; a bias voltage of 500 V is applied to the second DC high-voltage power supply 4 to deflect the ions to be tested onto the detection electrode 7, and the ion current I is recorded by the current meter 8; Figure 2 As shown, by recording the change of ion current I obtained by the detection electrode with scanning voltage Vr, and with Vr as the x-axis and the absolute value of dI / dVr as the y-axis, the curve Vr - |dI / dVr| can be plotted. The maximum value of the curve on the y-axis corresponds to the value on the x-axis, which is the average kinetic energy of the ions, 20.4 eV. The half-width of the curve obtained after Gaussian fitting is 2 V, that is, the ion energy width is 2 eV.

[0033] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these equivalent variations or substitutions are all included within the scope defined by the claims of this application.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ion kinetic energy measuring device, comprising a grid ground electrode (2), a grid deceleration electrode (9), a deflection electrode (5), an ion detection electrode (7), a first DC high-voltage power supply (3), a second DC high-voltage power supply (4), and a current meter (8); characterized in that: The X direction is to the right, and the Y direction is upward. The ion kinetic energy measuring device is provided from left to right with a grid ground electrode (2), a grid deceleration electrode (9), a deflection electrode (5), and an ion detection electrode (7). The grid ground electrode (2) and the grid deceleration electrode (9) are both flat plate structures with a circular through hole in the middle, and a metal grid parallel to the surface of the flat plate is provided on the through hole in the middle. The grid ground electrode (2) is connected to the ground potential (10) or grounded through a wire. The grid deceleration electrode (9) is connected to the first DC high voltage power supply (3) through a wire. The through holes in the middle of the grid ground electrode (2) and the grid deceleration electrode (9) are placed coaxially, spaced apart, and parallel. The deflection electrode (5) and the ion detection electrode (7) are both rectangular flat plate structures, which are symmetrically placed on both sides of the central axis of the through hole of the grid ground electrode (2) and the grid deceleration electrode (9) and are parallel to each other and spaced apart. The deflection electrode (5) is connected to the second DC high voltage power supply (4) through a wire. The ion detection electrode (7) is connected to the current meter (8) through a wire.

2. The ion kinetic energy measuring device according to claim 1, characterized in that: During operation, a scanning voltage Vr is applied to the grid deceleration electrode (9) through the first DC high voltage power supply (3), thereby tuning the electric field between the grid ground electrode (2) and the grid deceleration electrode (9), and thus controlling the advance of the test ions (1) with different energies; a voltage is applied to the deflection electrode (5) through the second DC high voltage power supply (4), deflecting the incoming test ions to the ion detection electrode (7) and recording the ion flow I through the current meter (8); the ion flow I obtained by recording the detection electrode changes with the scanning voltage Vr, i.e. dI and dVr; with Vr as the x-axis and the absolute value of dI / dVr as the y-axis, the curve of Vr-|dI / dVr| can be plotted, the maximum value of the curve on the y-axis corresponds to the value on the x-axis, which is the average kinetic energy of the ion, and the value corresponding to the half-peak width obtained after Gaussian fitting of the curve is the ion energy width.

3. The ion kinetic energy measuring device according to claim 1, characterized in that: The grid ground electrode (2) and the grid deceleration electrode (9) are made of stainless steel or a material with a conductive coating on the surface; the grid ground electrode (2) and the grid deceleration electrode (9) are in the shape of a circular ring or a polygonal plate structure.

4. The ion kinetic energy measuring device according to claim 1, characterized in that: The first DC high voltage power supply (3) and the second DC high voltage power supply (4) are precision DC power supplies; the current measuring meter (8) is a picoampere galvanometer.

5. The ion kinetic energy measuring device according to claim 1, characterized in that: The ion kinetic energy measurement device can be used as a unit module for measuring the ion beam current inside a mass spectrometer, or for the precise measurement of ion energy in an ion soft deposition device.

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