A photoelectron energy controllable ionization source

Abstract

The present invention belongs to the technical field of mass spectrometry ionization sources, and specifically relates to an ionization source with controllable photoelectron energy, comprising a vacuum ultraviolet light source and an ion repeller electrode, a lamp holder electrode, an ion transport electrode and an ion extraction electrode arranged in sequence from left to right along the axis direction of the injection port. The vacuum ultraviolet light emitted by the vacuum ultraviolet light source is perpendicular to the axis direction of the injection port. The metal grid is an integrated cylindrical or square cylindrical shape, and is vertically connected to the ion transport electrode through an insulating fixing column in the central through hole of the lamp holder electrode. The device provided by the present invention can both suppress photoelectrons and enhance photoelectrons, and the photoelectron energy can be flexibly and quickly adjusted by adjusting the voltage difference between the lamp holder electrode and the metal grid.

Description

Technical Field

[0001] This invention belongs to the field of mass spectrometry ionization source technology, specifically relating to an ionization source with controllable photoelectron energy. Background Technology

[0002] Under the photoelectric effect, when light shines on a metal surface, photoelectrons are emitted. These electrons gain energy in an electric field and can undergo photoionization.

[0003] Li Haiyang, Cao Yixue, et al. (application number CN202110992538.5) invented a photoelectron suppression ionization source device, which suppresses photoelectron generation and ensures a single single-photon ionization path by setting up a light-blocking tube and adding insulating materials. It can also achieve ion focusing, improve ion transmission efficiency, and effectively improve the dynamic range of sample measurement.

[0004] Currently, the control of photoelectrons within ionization sources is mainly achieved by suppressing their generation through insulating materials and light-blocking tubes. However, in some scenarios, it is also necessary to utilize photoelectrons, and existing devices still struggle to flexibly control the energy of photoelectrons over a wide range. Summary of the Invention

[0005] This invention proposes an ionization source with controllable photoelectron energy to solve the problem of narrow controllability range of existing photoelectron energy.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An ionization source with controllable photoelectron energy includes a vacuum ultraviolet light source and an ion repulsion electrode, a lamp head electrode, an ion transport electrode, and an ion extraction electrode arranged sequentially from left to right along the axis of the sample inlet.

[0008] The ion repulsion electrode, lamp head electrode, ion transport electrode, and ion extraction electrode are all plate structures with a central through hole, and are placed in parallel, spaced apart, and with the central through hole coaxial, on the same axis as the center of the sample inlet, perpendicular to the direction of the vacuum ultraviolet light emitted from the vacuum ultraviolet light source.

[0009] A metal grid is provided in the central through hole of the lamp head electrode. The metal grid is an integral cylindrical structure. The center of the lamp head electrode and the center of the metal grid are on the same axis. In the central through hole of the lamp head electrode, it is perpendicularly connected to the ion transport electrode through an insulating fixing post.

[0010] The ion repulsion electrode, metal grid, ion transport electrode, and ion extraction electrode are sequentially loaded with different voltages in descending order of absolute voltage value, forming an ion extraction electric field of 0-500V / cm in the axial direction.

[0011] Under the photoelectric effect, vacuum ultraviolet light emitted from a vacuum ultraviolet light source irradiates the sidewall of the lamp holder electrode, causing photoelectrons to escape. By adjusting the voltage difference between the lamp holder electrode and the metal grid, photoelectrons can be either suppressed or enhanced, thus achieving regulation of photoelectron energy.

[0012] A voltage different from that applied to the metal grid is applied to the lamp holder electrode, and the absolute value of the voltage difference does not exceed 500V.

[0013] When the voltage of the lamp holder electrode is higher than the voltage of the metal grid, photoelectrons move toward the side wall of the lamp holder electrode, collide with the lamp holder electrode and are annihilated, and the energy of the photoelectrons is 0.

[0014] When the voltage of the lamp holder electrode is lower than the voltage of the metal grid, photoelectrons move toward the central axis of the metal grid and gain a certain amount of energy. The smaller the absolute value of the voltage difference between the lamp holder electrode and the metal grid, the lower the energy of the photoelectrons. The larger the absolute value of the voltage difference between the lamp holder electrode and the metal grid, the higher the energy of the photoelectrons.

[0015] The ion transport electrode is a plate structure that is spaced apart from each other, coaxial, and parallel. When there is more than one ion transport electrode, different voltages are applied to the multiple ion transport electrodes from left to right in order of decreasing absolute voltage value.

[0016] The metal grid is an integral cylindrical or square structure.

[0017] The ionization region pressure between the ion repulsion electrode and the ion extraction electrode is maintained at 10. -3 Pa~10 3 Pa.

[0018] The diameter of the central through hole of the ion transport electrode is 1-20 mm; the diameter of the central through hole of the ion extraction electrode is 0.1-5 mm; the distance between the ion repulsion electrode and the ion extraction electrode is 10-250 mm; and the distance between the metal grid and the lamp holder electrode is 0.5-10 mm.

[0019] The vacuum ultraviolet light source is a gas discharge lamp, an ultraviolet light-emitting diode, a synchrotron radiation source, or a laser source.

[0020] Beneficial effects

[0021] The ionization source with controllable photoelectron energy provided by this invention can both suppress and enhance photoelectrons. By adjusting the voltage difference between the lamp head electrode and the metal grid, the photoelectron energy can be flexibly and quickly adjusted. Attached Figure Description

[0022] The accompanying drawings further illustrate the present invention, but the content of the drawings does not constitute any limitation on the present invention.

[0023] Figure 1 This invention relates to an ionization source with controllable photoelectron energy.

[0024] In the figure, 1. Vacuum ultraviolet light source; 2. Sample inlet; 3. Ion repulsion electrode; 4. Lamp head electrode; 5. Vacuum ultraviolet light; 6. Metal grid; 7. Insulating fixing column; 8. Ion transport electrode; 9. Ion extraction electrode. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] Example 1

[0032] like Figure 1 As shown, this invention provides a photoelectron energy controllable ionization source, comprising a vacuum ultraviolet light source 1 and ion repulsion electrode 3, lamp head electrode 4, ion transport electrode 8, and ion extraction electrode 9 arranged sequentially from left to right along the axis of the sample inlet 2.

[0033] The ion repulsion electrode 3, lamp head electrode 4, ion transport electrode 8 and ion extraction electrode 9 are all plate structures with a central through hole, and are placed in parallel, spaced apart, and with the central through hole coaxial. They are on the same axis as the center of the sample inlet 2 and perpendicular to the direction of the vacuum ultraviolet light 5 emitted from the vacuum ultraviolet light source 1.

[0034] A metal grid 6 is provided in the central through hole of the lamp holder electrode 4. The metal grid 6 is an integral cylindrical or square tube. The center of the lamp holder electrode 4 and the metal grid 6 are on the same axis. In the central through hole of the lamp holder electrode 4, it is perpendicularly connected to the ion transport electrode 8 through an insulating fixing post 7. Preferably, as one embodiment, the metal grid 6 is an integral cylindrical shape.

[0035] Ion repulsion electrode 3, metal grid 6, ion transport electrode 8 and ion extraction electrode 9 are sequentially loaded with different voltages in descending order of absolute voltage value, forming an ion extraction electric field of 0-500V / cm in the axial direction.

[0036] Under the influence of the photoelectric effect, the vacuum ultraviolet light 5 emitted from the vacuum ultraviolet light source 1 irradiates the sidewall of the lamp head electrode 4, causing photoelectrons to be emitted. By adjusting the voltage difference between the lamp head electrode 4 and the metal grid 6, photoelectrons can be either suppressed or enhanced, thus achieving the regulation of photoelectron energy.

[0037] A voltage different from that applied to the metal grid 6 is applied to the lamp holder electrode 4, and the absolute value of the voltage difference does not exceed 500V.

[0038] In one embodiment, the voltage of the ion repulsion electrode 3 is 22V; the voltage of the metal grid 6 is 18V; the ion transport electrode 8 is a plate structure consisting of three spaced, coaxial, and parallel plates with voltages of 12V, 10V, and 8V respectively; and the voltage of the ion extraction electrode 9 is 5V.

[0039] When the voltage of the lamp head electrode 4 is higher than the voltage of the metal grid 6, in one embodiment, the absolute value of the voltage difference is 70V, that is, the voltage of the lamp head electrode 4 is 88V. The photoelectrons move toward the side wall of the lamp head electrode 4, collide with the lamp head electrode 4 and are annihilated, and the photoelectron energy is 0.

[0040] When the voltage of the lamp holder electrode 4 is lower than the voltage of the metal grid 6, in one embodiment, the absolute value of the voltage difference is 70V, that is, the voltage of the lamp holder electrode 4 is -52V, and photoelectrons move towards the central axis of the metal grid 6 and obtain 70eV of energy; when the absolute value of the voltage difference between the lamp holder electrode 4 and the metal grid 6 decreases to 40V, that is, the voltage of the lamp holder electrode 4 is -22V, the photoelectron energy decreases to 40eV; when the absolute value of the voltage difference between the lamp holder electrode 4 and the metal grid 6 increases to 100V, that is, the voltage of the lamp holder electrode 4 is -82V, the photoelectron energy increases to 100eV.

[0041] Preferably, the ionization region pressure between the ion repulsion electrode 3 and the ion extraction electrode 9 is 1 Pa.

[0042] Preferably, the diameter of the central through hole of the ion transport electrode 8 is 10 mm; the diameter of the central through hole of the ion extraction electrode 9 is 1 mm; the distance between the ion repulsion electrode 3 and the ion extraction electrode 9 is 50 mm; and the distance between the metal grid 6 and the lamp holder electrode 4 is 2 mm.

[0043] Vacuum ultraviolet light source 1 can be a gas discharge lamp, an ultraviolet light-emitting diode, a synchrotron radiation source, or a laser source.

[0044] 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.

[0045] 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. A photoelectron energy controllable ionization source, characterized in that: It comprises a vacuum ultraviolet light source (1) and an ion repeller electrode (3), a lamp holder electrode (4), an ion transport electrode (8) and an ion extraction electrode (9) which are arranged in sequence from left to right along the axis direction of the injection port (2); The ion repeller electrode (3), the lamp holder electrode (4), the ion transport electrode (8) and the ion extraction electrode (9) are all plate-type structures with a central through hole, and are arranged in parallel, spaced apart, and coaxially with the central through hole, on the same axis as the center of the injection port (2), and perpendicular to the direction of the vacuum ultraviolet light (5) emitted by the vacuum ultraviolet light source (1); A metal grid (6) is provided in the central through hole of the lamp cap electrode (4), the metal grid (6) is an integrated cylindrical structure, the centers of the lamp cap electrode (4) and the metal grid (6) are on the same axis, and the metal grid (6) is vertically connected to the ion transport electrode (8) through an insulating fixing column (7) in the central through hole of the lamp cap electrode (4); The ion repelling electrode (3), the metal grid (6), the ion transport electrode (8) and the ion extraction electrode (9) are sequentially loaded with different voltages in the order of the absolute value of the voltage from high to low, so as to form an ion extraction electric field in the axial direction; The photoelectron energy is regulated by adjusting the voltage difference between the lamp cap electrode (4) and the metal grid (6).

2. The photoelectron energy controllable ionization source according to claim 1, characterized in that: A voltage different from that of the metal grid (6) is applied to the lamp cap electrode (4), and the absolute value of the voltage difference does not exceed 500 V; When the voltage of the lamp cap electrode (4) is higher than the voltage of the metal grid (6), the photoelectrons move toward the side wall of the lamp cap electrode (4), collide with the lamp cap electrode (4) and are annihilated, and the energy of the photoelectrons is 0; When the voltage of the lamp cap electrode (4) is lower than the voltage of the metal grid (6), the photoelectrons move toward the central axis of the metal grid (6) and acquire a certain amount of energy; the smaller the absolute value of the voltage difference between the lamp cap electrode (4) and the metal grid (6), the lower the energy of the photoelectrons; and the larger the absolute value of the voltage difference between the lamp cap electrode (4) and the metal grid (6), the higher the energy of the photoelectrons.

3. The photoelectron energy controllable ionization source according to claim 1, characterized in that: The ion transport electrode (8) is a plate-type structure that is spaced apart from each other, coaxially and parallelly arranged in one piece or more pieces; when there is more than one ion transport electrode (8), different voltages are sequentially loaded on the multiple ion transport electrodes from left to right in the order of the absolute value of the voltage from high to low.

4. The photoelectron energy controllable ionization source according to claim 1, characterized in that: The metal grid (6) is an integrated cylindrical or square cylindrical structure.

5. The photoelectron energy controllable ionization source according to claim 1, characterized in that: The gas pressure in the ionization zone between the ion repeller electrode (3) and the ion extraction electrode (9) is maintained at 10- 3 Pa~10 3 Pa.

6. The photoelectron energy controllable ionization source according to claim 1, characterized in that: The diameter of the central through hole of the ion transmission electrode (8) is 1 to 20 mm; the diameter of the central through hole of the ion extraction electrode (9) is 0.1 to 5 mm; the distance between the ion repeller electrode (3) and the ion extraction electrode (9) is 10 to 250 mm; and the distance between the metal grid (6) and the lamp holder electrode (4) is 0.5 to 10 mm.

7. The photoelectron energy controllable ionization source according to claim 1, characterized in that: The vacuum ultraviolet light source (1) is a gas discharge lamp, an ultraviolet light emitting diode, a synchrotron radiation light source or a laser light source.

Images