Mass spectrometry apparatus and method based on an ecr ion source

Abstract

The application provides an ECR ion source-based mass spectrum detection device and method, which comprises an ECR ion source, a multipole rod mass analyzer, a detector and a power supply; further comprises a first ion focusing lens and an ion deceleration lens, the first ion focusing lens is arranged on an ion transmission path between the ECR ion source and the multipole rod mass analyzer; the ion deceleration lens is arranged on the ion transmission path and between the first ion focusing lens and the multipole rod mass analyzer; the power supply applies voltage to the first ion focusing lens and the ion deceleration lens. The application has the advantages of high sensitivity.

Description

TECHNICAL FIELD

[0001] The present application relates to mass spectrometry, in particular to a mass spectrometry detection device and method based on an ECR ion source. BACKGROUND

[0002] With the development and application of nuclear technology, the increasing demand for instrument isotope accuracy and sensitivity of nuclear stations, the original mass spectrometer instrument and equipment are challenged. For example, ICP-MS, the intensity of the ion beam after ICP ionization of the sample is about uA, after the attenuation in the ion transmission process, the ion flow intensity is about pA when reaching the quadrupole, and the background interference is introduced, so the sensitivity is generally not high, and the trace elements in the sample cannot be accurately quantified; for example, AMS cannot measure gas samples, especially inert gases, and the instrument is too large, the structure is complex, and the operation is difficult; for example, magnetic mass spectrometry, although the resolution is high, but the manufacturing difficulty is large, and the cost is high. Therefore, the ion source ECR source in the magnetic mass spectrometer can be connected in series with the analyzer part of the ordinary quadrupole mass spectrometer to form a system, which can not only take advantage of the strong ion beam (mA level) introduced by the ECR ion source and the advantage of no molecular background interference of multi-charge state, but also take advantage of the high resolution measurement and high isotope precision ratio of the quadrupole mass spectrometer, so that the sensitivity can be improved by 2-3 orders of magnitude, and the test accuracy can be further improved.

[0003] The ECR ion source is different from the working principle of ICP, and can produce an ion beam with high beam intensity. The high-energy ion beam is obtained through the high-voltage extraction of the rear-end extraction electrode. The flow intensity of the ion beam is often in the order of mA, and the kinetic energy is up to thousands of eV or even tens of hundreds of eV. For the quadrupole mass spectrometer, in order to successfully analyze the target ions and realize unit resolution, the kinetic energy of the ion beam entering the quadrupole is about 10 eV, and the beam spot size should be circular, so that the ions can continue to have this energy to reach the subsequent second-stage quadrupole and detector. Therefore, how to decelerate the high-energy ion beam and couple it into the quadrupole to realize screening is very important. SUMMARY

[0004] In order to solve the problems in the prior art, the present application provides a mass spectrometry detection device based on an ECR ion source.

[0005] The purpose of the present application is achieved by the following technical solutions:

[0006] The mass spectrometry detection device based on the ECR ion source comprises an ECR ion source, a multipole rod mass analyzer, a detector and a power supply; the mass spectrometry detection device based on the ECR ion source further comprises:

[0007] a first ion focusing lens, which is arranged on an ion transmission path between the ECR ion source and a multipole rod mass analyzer;

[0008] an ion deceleration lens, which is arranged on the ion transmission path and between the first ion focusing lens and the multipole rod mass analyzer; and the power supply applies voltage to the first ion focusing lens and the ion deceleration lens.

[0009] The application also provides an ECR ion source-based mass spectrum detection method.

[0010] The ECR ion source-based mass spectrum detection method is characterized in that:

[0011] The application provides an ECR ion source-based mass spectrum detection device.

[0012] The ions emitted from the ECR ion source pass through the first ion focusing lens, the deceleration lens and the multipole rod mass analyzer in sequence and enter the detector.

[0013] Compared with the prior art, the application has the beneficial effects that:

[0014] 1. High sensitivity;

[0015] By arranging the deceleration lens, the ion beam can be rapidly reduced from several thousand electron volts to about 10eV, the cross-sectional shape of the ion beam is still circular, and the ion beam can be focused once or twice inside to reduce the spot radius;

[0016] By arranging the focusing lens, the divergent ion beam is further focused, the divergence of the ion beam is reduced, the influence of the space charge effect is reduced, the ion transmission efficiency is improved, and thus the sensitivity is improved;

[0017] 2. Good safety;

[0018] The negative high-voltage extraction mode is adopted to adjust the potential of the extraction electrode, so that when the ions are decelerated and reach the quadrupole rod, the overall potential of the quadrupole rod is near the ground potential, and the safety of the rear-end instrument is ensured, and the overall circuit design is simpler. BRIEF DESCRIPTION OF DRAWINGS

[0019] The disclosure of the application will become more apparent with reference to the accompanying drawings. It is easy for those skilled in the art to understand that the drawings are only used to illustrate the technical solutions of the application, and are not intended to limit the protection scope of the application. In the drawings:

[0020] Figure 1is a structural schematic diagram of an ECR ion source-based mass spectrometry detection device according to an embodiment of the present application. DETAILED DESCRIPTION

[0021] Figure 1 The alternative embodiments of the present application described below are presented to teach those skilled in the art how to make and use the present application. Some conventional aspects have been simplified or omitted for the sake of clarity. Those skilled in the art should appreciate that variations in the embodiments described herein that depart from the present application will still fall within the scope of the present application. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the present application. As a result, the present application is not limited to the alternative embodiments described below, but only by the claims and their equivalents.

[0022] Embodiment 1

[0023] Figure 1 A structural schematic diagram of an ECR ion source-based mass spectrometry detection device according to an embodiment of the present application is given as shown in Figure 1 The ECR ion source-based mass spectrometry detection device includes:

[0024] an ECR ion source, a multipole rod mass analyzer 30, a detector, and a power supply; these devices are all prior art in the field;

[0025] a first ion focusing lens 10, which is disposed on an ion transmission path between the ECR ion source and the multipole rod mass analyzer 30;

[0026] an ion deceleration lens 20, which is disposed on the ion transmission path and between the first ion focusing lens 10 and the multipole rod mass analyzer 30; the power supply applies voltage to the first ion focusing lens 10 and the ion deceleration lens 20.

[0027] To better focus the ions, further, the first ion focusing lens 10 includes a plurality of sequentially disposed cylindrical electrodes 11.

[0028] To reduce the kinetic energy of the ions, further, the deceleration lens includes a flat plate electrode and a cylindrical electrode 23, which is disposed between two flat plate electrodes, the flat plate electrodes having through holes that allow the ions to pass through.

[0029] To reduce the kinetic energy of the ions, further, the flat plate electrodes are a first flat plate electrode 21, a second flat plate electrode 22, and a third flat plate electrode 24, which are sequentially disposed, and the cylindrical electrode 23 is disposed on the ion transmission path between the second flat plate electrode 22 and the third flat plate electrode 24.

[0030] To reduce the kinetic energy of the ions, further, the second flat electrode 22 has a larger diameter of the through hole than the first flat electrode 21.

[0031] To further focus the ions, further, the ECR ion source based mass spectrometry detection device further comprises:

[0032] A second ion focusing lens is arranged on the ion transmission path between the multipole rod mass analyzer 30 and the detector, and the power supply applies a focusing voltage to the second ion focusing lens.

[0033] The ECR ion source based mass spectrometry detection method of the embodiment of the present application is:

[0034] The ECR ion source based mass spectrometry detection device of the embodiment of the present application is provided;

[0035] The ions emitted from the ECR ion source pass through the first ion focusing lens 10, the deceleration lens 20 and the multipole rod mass analyzer 30 in sequence, and enter the detector.

[0036] To further focus the ions, further, the ions pass through the multipole rod mass analyzer 30 and the second ion focusing lens in sequence, and enter the detector.

[0037] Embodiment 2:

[0038] Application example of the ECR ion source based mass spectrometry detection device and method according to the embodiment 1 of the present application.

[0039] In this application example, as shown in Figure 1 The first focusing lens 10, the deceleration lens 20 and the quadrupole rod mass analyzer 30 are arranged in sequence; the distance between the deceleration lens 20 and the first focusing lens 10 is 100 mm;

[0040] The first ion focusing lens comprises three (first-third) cylindrical electrodes 11 arranged in sequence, each cylindrical electrode 11 is 12 mm long, 35 mm in inner diameter, 2 mm in thickness, and 5 mm in electrode spacing;

[0041] The deceleration lens 20 comprises three flat electrodes and a cylindrical electrode 23, including flat electrodes arranged in sequence, the first flat electrode 21 is 2 mm thick, 40 mm in outer diameter, and 6 mm in inner diameter of the through hole; the second flat electrode 22 is 2 mm thick, 40 mm in outer diameter, and 10 mm in inner diameter of the through hole; the third flat electrode 24 is 2 mm thick, 40 mm in outer diameter, and 10 mm in inner diameter; the spacing between each lens is 15 mm; the cylindrical electrode 23 is 20 mm long, 2 mm thick, and 10 mm in inner diameter, and is arranged on the ion transmission path between the second flat electrode 22 and the third flat electrode 24.

[0042] The central axis of each of the cylindrical electrodes is coaxial with the central axis of the through hole of each of the flat plate electrodes.

[0043] The voltage applied to each electrode by the power supply is as follows:

[0044]

[0045] The simulation results (without the extraction electrode) are as follows:

[0046] The mass range of the incident ions is from 5-250amu, the ion beam half divergence angle is 2.0°, the ion incident kinetic energy is 500eV, the outgoing kinetic energy is 7.52ev, at this time the outgoing ion beam is close to parallel, the cross-sectional shape is circular, and the ion beam diameter at 480mm is 4.8mm.

[0047] Embodiment 3:

[0048] According to the application example of the ECR ion source-based mass spectrum detection device and method according to Embodiment 1 of the present application, different from Embodiment 2 is that:

[0049] The initial kinetic energy of the ions is 10eV, the spot diameter of the ion beam before extraction is 1mm, after extraction by the extraction electrode, the kinetic energy is about 1000eV, and the voltage of each electrode sheet is as follows:

[0050]

[0051]

[0052] The simulation results (with the extraction electrode) are as follows:

[0053] The ion beam can be focused after passing through the deceleration lens, and the kinetic energy of the ion beam is attenuated to 16.52eV after passing through the deceleration lens, and effective focusing can be performed at the rear end. At this time, the focusing position and the outgoing spot size of the ion beam can be changed by changing the voltage of the deceleration electrode, and the ion transmission rate is 100%.

[0054] Embodiment 4:

[0055] According to the application example of the ECR ion source-based mass spectrum detection device and method according to Embodiment 1 of the present application, different from Embodiment 2 is that:

[0056] A second focusing lens is arranged on the ion transmission path between the deceleration lens and the quadrupole mass analyzer, which is the same as the first focusing lens.

[0057] Embodiment 5:

[0058] According to the application example of the ECR ion source-based mass spectrum detection device and method according to Embodiment 1 of the present application, different from Embodiment 2 is that:

[0059] An ion deflection lens is provided on the ion transmission path between the deceleration lens and the quadrupole rod mass analyzer.

Claims

1. A mass spectrometry detection device based on an ECR ion source, comprising an ECR ion source, a multipole rod mass analyzer, a detector, and a power supply; characterized in that, The ECR ion source-based mass spectrometry detection device further comprises: a first ion focusing lens arranged on an ion transmission path between the ECR ion source and the multipole rod mass analyzer; an ion deceleration lens arranged on the ion transmission path and between the first ion focusing lens and the multipole rod mass analyzer; the power supply applies voltage to the first ion focusing lens and the ion deceleration lens; The deceleration lens comprises a flat plate electrode and a cylindrical electrode arranged between two flat plate electrodes, the flat plate electrode has a through hole allowing ions to pass through; the flat plate electrode is sequentially arranged as a first flat plate electrode, a second flat plate electrode and a third flat plate electrode, and the cylindrical electrode is arranged on the ion transmission path between the second flat plate electrode and the third flat plate electrode; the through hole diameter of the second flat plate electrode is greater than the through hole diameter of the first flat plate electrode, and equal to the inner diameter of the cylindrical electrode and the through hole diameter of the third flat plate electrode.

2. The ECR ion source-based mass spectrometric detection device according to claim 1, characterized in that, The first ion focusing lens comprises a plurality of cylindrical electrodes arranged in sequence.

3. The ECR ion source based mass spectrometer detection device of claim 1, wherein, The ECR ion source-based mass spectrometry detection device further comprises: a second ion focusing lens arranged on an ion transmission path between the multipole rod mass analyzer and the detector, and the power supply applies a focusing voltage to the second ion focusing lens.

4. The ECR ion source-based mass spectrometer detection device according to claim 1, characterized by, The ECR ion source-based mass spectrometry detection device further comprises: an extraction electrode arranged on an ion transmission path between the ECR ion source and the first focusing lens.

5. The ECR ion source based mass spectrometer detection device of claim 1, wherein, The ECR ion source-based mass spectrometry detection device further comprises: a deflection electrode arranged between the multipole rod mass analyzer and the detector.

6. An ECR ion source-based mass spectrometry detection method, the ECR ion source-based mass spectrometry detection method comprising: providing the ECR ion source-based mass spectrometry detection device according to any one of claims 1-2; ions emitted from the ECR ion source sequentially pass through the first ion focusing lens, the deceleration lens and the multipole rod mass analyzer, and enter the detector.

7. The method of mass spectrometry detection based on an ECR ion source according to claim 6, characterized in that, ions sequentially pass through the multipole rod mass analyzer and the second ion focusing lens, and enter the detector.

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