Hydrogen isotope mass spectrometer gas inlet system and use method thereof

Abstract

The invention provides a hydrogen isotope mass spectrometer gas inlet system and a using method thereof. The hydrogen isotope mass spectrometer gas inlet system comprises a gas mixing chamber, and a sample bottle is connected with the gas mixing chamber through a gas pipe; the supporting gas cylinder is connected with the gas mixing chamber through a gas pipe; the recycling bottle is connected with the gas mixing chamber through a gas pipe; the ion source is connected with the gas mixing chamber through a gas pipe; the dry pump and the molecular pump are respectively connected with the gas mixing chamber through gas pipes, and the ionization gauge and the resistance gauge are respectively connected with the gas mixing chamber. A hydrogen isotope gas sample can continuously and quantitatively enter the mass spectrometer, the system can mix the hydrogen isotope gas and the supporting gas according to a specific proportion, the supporting gas can inhibit generation of molecular ions in the ionization process in an ion source, and the proportion of hydrogen isotope monatomic ions is increased. The sample introduction system can realize negative pressure sample introduction and ensure that sample gas in the ion source is fully ionized. A sample recovery bottle is arranged, so that redundant samples in the gas mixing chamber can be recovered.

Description

Technical Field

[0001] The present invention relates to the technical field of isotope analyzers, and in particular to an air intake system for a hydrogen isotope mass spectrometer and a use method thereof. Background Art

[0002] In order to achieve accurate simultaneous measurement of the isotope abundance of H, D, and T in hydrogen isotope samples and the impurity content of C, N, O, etc. in the samples, a hydrogen isotope mass spectrometer is required, and hydrogen isotope gas is used as the sample to be measured. The existing hydrogen isotope mass spectrometer gas injection methods include closed circulation system injection method, pulse injection method, continuous flow injection method, gas diffusion injection method, and valve control system injection method. Most traditional gas injection systems are based on positive pressure injection, which cannot guarantee accurate micro-injection of samples, resulting in unnecessary waste of samples; and most of the gas injection systems cannot achieve injection after mixing different gases in a specific ratio. Summary of the invention

[0003] The object of the present invention is to provide a hydrogen isotope mass spectrometer gas inlet system and a use method thereof, so as to achieve continuous and quantitative entry of hydrogen isotope gas samples into the mass spectrometer.

[0004] According to one object of the present invention, the present invention provides a hydrogen isotope mass spectrometer gas intake system, including a gas mixing chamber, a sample gas intake channel, a support gas intake channel, a sample gas recovery channel, a mixed gas injection channel and a vacuum system, wherein the sample gas intake channel includes a sample bottle, and the sample bottle is connected to the gas mixing chamber through an air pipe; the support gas intake channel includes a support gas cylinder, and the support gas cylinder is connected to the gas mixing chamber through an air pipe; the sample gas recovery channel includes a recovery bottle, and the recovery bottle is connected to the gas mixing chamber through an air pipe; the mixed gas injection channel includes an ion source, and the ion source is connected to the gas mixing chamber through an air pipe; the vacuum system includes a dry pump, a molecular pump, an ionization gauge and a resistance gauge, the dry pump and the molecular pump are respectively connected to the gas mixing chamber through an air pipe, and the ionization gauge and the resistance gauge are respectively connected to the gas mixing chamber.

[0005] Furthermore, a pressure gauge is provided on the gas mixing chamber.

[0006] Furthermore, a manual valve II and a solenoid valve II are provided on the pipeline between the sample bottle and the gas mixing chamber; a pressure reducing valve I, a solenoid valve I and a manual valve I are provided on the pipeline between the support gas bottle and the gas mixing chamber; and a manual valve III and a solenoid valve III are provided on the pipeline between the recovery bottle and the gas mixing chamber.

[0007] Furthermore, a solenoid valve IV and a mass flow controller are provided between the ion source and the gas mixing chamber; a plug valve and a manual valve IV are provided on the connecting pipelines between the dry pump, the molecular pump and the gas mixing chamber.

[0008] According to another object of the present invention, the present invention provides a method for using the above-mentioned hydrogen isotope mass spectrometer intake system, comprising the following steps:

[0009] S1. First, evacuate the gas mixing chamber;

[0010] S2, then inject a certain amount of sample gas through the sample gas inlet channel;

[0011] S3, injecting a set proportion of supporting gas through the supporting gas inlet channel;

[0012] S4, finally injecting the sample into the ion source through the mixed gas injection channel;

[0013] S5. Recover excess sample through the sample gas recovery channel.

[0014] Further, the process of vacuuming the mixing chamber:

[0015] First, open the dry pump, plug valve, manual valve IV and resistance gauge in sequence, evacuate the gas mixing chamber, and observe the resistance gauge indication. When the vacuum in the gas mixing chamber is lower than 5Pa, turn on the molecular pump to continue evacuating the chamber and turn on the ionization gauge; observe the ionization gauge indication. When the vacuum in the gas mixing chamber is lower than 10-4Pa, close the manual valve IV, plug valve and molecular pump in sequence. When the molecular pump speed is 0, turn off the dry pump and the ionization gauge.

[0016] Furthermore, the sample gas pipeline intake process:

[0017] Open manual valve II and solenoid valve II in sequence, and inject the gas in the sample bottle into the gas mixing chamber through the air pipe. Observe the pressure change in the gas mixing chamber through the pressure gauge. When the pressure reaches the target value, close solenoid valve II and manual valve II in sequence.

[0018] Further, the support gas intake process:

[0019] Open the pressure reducing valve, solenoid valve I and manual valve I in sequence, and the supporting gas enters the mixing chamber through the air pipe. Observe the pressure change in the mixing chamber through the pressure gauge. When the pressure value reaches the predetermined target value, close the manual valve I, solenoid valve I and pressure reducing valve in sequence.

[0020] Further, the mixed gas injection process:

[0021] Open the solenoid valve IV, set the mass flow controller flow rate, and inject the mixed gas through the gas pipe at a specific flow rate; when the injection is finished, first set the mass flow controller flow rate to zero, and then close the solenoid valve IV.

[0022] Further, the sample recovery process:

[0023] Open the solenoid valve III and the manual valve III to recover the excess sample in the gas mixing chamber.

[0024] The technical solution of the present invention can realize the continuous quantitative entry of hydrogen isotope gas samples into the mass spectrometer. The system is provided with a sample gas injection pipeline, a support gas injection pipeline, a gas mixing chamber, a sample recovery pipeline and a vacuum system. The hydrogen isotope gas and the support gas can be mixed in a specific proportion. The support gas can suppress the generation of molecular ions in the ionization process inside the ion source and increase the proportion of hydrogen isotope monatomic ions. The injection system can realize negative pressure injection to ensure that the sample gas inside the ion source is fully ionized. A sample recovery bottle is provided to recover the excess sample in the gas mixing chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of a hydrogen isotope mass spectrometer according to Example 3 of the present invention;

[0028] In the figure: 1, gas mixing chamber; 2, pressure gauge; 3, sample bottle; 4, manual valve II; 5, solenoid valve II; 6, support gas bottle; 7, pressure reducing valve; 8, solenoid valve I; 9, manual valve I; 10, recovery bottle; 11, manual valve III; 12, solenoid valve III; 13, ion source; 14, solenoid valve IV; 15, mass flow controller; 16, dry pump; 17, molecular pump; 18, ionization gauge; 19, resistance gauge; 20, gate valve; 21, manual valve IV;

[0029] 22. Air intake system; 23. ECR ion source; 24. Accelerator tube; 25. Magnetic analyzer; 26. Faraday cup; 27. Ion detector. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Example 1

[0034] like Figure 1 As shown:

[0035] A gas inlet system for a hydrogen isotope mass spectrometer comprises a gas mixing chamber 1, a sample gas inlet channel, a support gas inlet channel, a sample gas recovery channel, a mixed gas inlet channel and a vacuum system, wherein:

[0036] A pressure gauge 2 is provided on the gas mixing chamber 1;

[0037] The sample gas inlet channel includes a sample bottle 3, a manual valve II 4, a solenoid valve II 5 and an air pipe. The sample bottle 3 is connected to the gas mixing chamber 1 through the air pipe. A manual valve II 4 and a solenoid valve II 5 are provided on the pipeline between the sample bottle 3 and the gas mixing chamber 1.

[0038] The supporting gas inlet passage includes a supporting gas cylinder 6, a pressure reducing valve 7, a solenoid valve 1 8, a manual valve 1 9 and an air pipe. The supporting gas cylinder 6 is connected to the gas mixing chamber 1 through the air pipe. The pipeline between the supporting gas cylinder 6 and the gas mixing chamber 1 is provided with a pressure reducing valve 7, a solenoid valve 1 8 and a manual valve 1 9;

[0039] The sample gas recovery channel includes a recovery bottle 10, a manual valve III 11, a solenoid valve III 12 and an air pipe. The recovery bottle 10 is connected to the gas mixing chamber 1 through the air pipe. The manual valve III 11 and the solenoid valve III 12 are arranged on the pipeline between the recovery bottle 10 and the gas mixing chamber 1.

[0040] The mixed gas injection channel includes an ion source 13, a solenoid valve IV 14, a mass flow controller 15 and an air pipe. The ion source 13 is connected to the gas mixing chamber 1 through the air pipe. The solenoid valve IV 14 and the mass flow controller 15 are provided between the ion source 13 and the gas mixing chamber 1.

[0041] The vacuum system includes a dry pump 16, a molecular pump 17, an ionization gauge 18 and a resistance gauge 19. The dry pump 16 and the molecular pump 17 are connected to the gas mixing chamber 1 through air pipes, respectively. A plug valve 20 and a manual valve IV 21 are provided on the connecting pipelines between the dry pump 16, the molecular pump 17 and the gas mixing chamber 1. The ionization gauge 18 and the resistance gauge 19 are connected to the gas mixing chamber 1, respectively.

[0042] In the embodiment of the present invention:

[0043] The process of mixing gas and injecting mixed gas in the mixing chamber 1 is as follows:

[0044] First, the gas mixing chamber 1 is evacuated, and then a certain amount of sample gas is injected through the sample gas inlet channel, and then a specific proportion of support gas is injected through the support gas inlet channel, and finally the sample is injected into the ion source 13 through the mixed gas injection channel.

[0045] The process of vacuuming the mixing chamber 1 is as follows:

[0046] First, open the dry pump 16, the plug valve, the manual valve IV21 and the resistance gauge 19 in sequence, evacuate the gas mixing chamber 1, and observe the resistance gauge 19 reading. When the vacuum degree in the gas mixing chamber 1 is lower than 5Pa, open the molecular pump 17 to continue evacuating the gas mixing chamber 1, and open the ionization gauge 18. Observe the reading of the ionization gauge 18. When the vacuum degree in the gas mixing chamber 1 is lower than 10Pa, -4 When Pa, the manual valve IV21, the gate valve and the molecular pump 17 are closed in sequence. When the speed of the molecular pump 17 is 0, the dry pump 16 is closed and the ionization gauge 18 is closed.

[0047] The sample gas pipeline intake process is as follows:

[0048] Open the manual valve II 4 and the solenoid valve II 5 in sequence, and inject the gas in the sample bottle 3 into the mixing chamber 1 through the air pipe. Observe the pressure change in the mixing chamber 1 through the pressure gauge 2. When the pressure reaches the target value, close the solenoid valve II 5 and the manual valve II 4 in sequence.

[0049] The support gas intake process is:

[0050] Open the pressure reducing valve 7, solenoid valve I 8 and manual valve I 9 in sequence, and the supporting gas enters the mixing chamber 1 through the air pipe. The air pressure change in the mixing chamber 1 is observed by the pressure gauge 2. When the pressure value reaches the predetermined target value, close the manual valve I 9, solenoid valve I8 and pressure reducing valve 7 in sequence.

[0051] The mixed gas injection process is:

[0052] The electromagnetic valve IV 14 is opened, the flow rate of the mass flow controller 15 is set, and the mixed gas is injected through the gas pipe at a specific flow rate; when the injection is finished, the flow rate of the mass flow controller 15 is first set to zero, and then the electromagnetic valve IV 14 is closed.

[0053] The gas injection system of the present invention adopts a valve control system injection method to realize continuous quantitative entry of hydrogen isotope gas samples into a mass spectrometer. The system is provided with a sample gas injection pipeline, a support gas injection pipeline, a gas mixing chamber 1, a sample recovery pipeline and a vacuum system. Compared with the traditional mass spectrometer gas injection system, the present invention can mix hydrogen isotope gas and support gas in a specific ratio. The support gas can suppress the generation of molecular ions in the ionization process inside the ion source 13, and increase the proportion of hydrogen isotope monatomic ions.

[0054] The present invention can accurately realize continuous micro-injection of hydrogen isotope samples by controlling the valve, the injection volume is small and the injection is continuous and stable, thereby avoiding sample waste; the present invention can realize negative pressure injection, ensure that the sample inside the ion source 13 is fully ionized, and avoid affecting the hydrogen isotope monatomic ion yield due to excessive injection volume; the present invention can recycle the hydrogen isotope gas after analysis, which is convenient for subsequent reuse.

[0055] Example 2

[0056] The structures of this embodiment and the above embodiment are basically the same. In this embodiment, Ar is selected as the supporting gas and H2 is selected as the sample gas to achieve 1:2 injection of H2 and Ar mixed gas.

[0057] When this embodiment is in operation:

[0058] First, evacuate the mixing chamber 1, open the dry pump 16, the plug valve, the manual valve IV21 and the resistance gauge 19 in sequence, evacuate the mixing chamber 1, and observe the resistance gauge 19 reading. When the vacuum degree in the mixing chamber 1 is lower than 5Pa, open the molecular pump 17 to continue evacuating the chamber, and open the ionization gauge 18. Observe the reading of the ionization gauge 18. When the vacuum degree in the mixing chamber 1 is lower than 10Pa, -4 When Pa, the manual valve IV21, the gate valve and the molecular pump 17 are closed in sequence. When the speed of the molecular pump 17 is 0, the dry pump 16 is closed and the ionization gauge 18 is closed.

[0059] Then introduce H2 into the mixing chamber 1, open the manual valve II 4 and the solenoid valve II 5 in turn, and inject the H2 in the sample bottle 3 into the mixing chamber 1 through the air pipe. Observe the air pressure in the mixing chamber 1 through the pressure gauge 2. When the air pressure reaches 12 kPa, close the solenoid valve II5 and the manual valve II 4 in turn.

[0060] Secondly, Ar is introduced into the mixing chamber 1, and the pressure reducing valve 7, solenoid valve I 8 and manual valve I 9 are opened in sequence. The supporting gas enters the mixing chamber 1 through the air pipe, and the air pressure change in the mixing chamber 1 is observed by the pressure gauge 2. When the pressure value reaches 36 kPa, the manual valve I 9, solenoid valve I 8 and pressure reducing valve 7 are closed in sequence, thereby achieving the mixing of the sample gas H2 and the supporting gas Ar in the mixing chamber 1 in a ratio of 1:2.

[0061] The mixed gas injection process is:

[0062] The electromagnetic valve IV 14 is opened, the flow meter flow rate is set to 0.01 sccm, and the mixed gas is injected into the ion source 13 through the gas pipe; when the injection is finished, the flow rate of the mass flow controller 15 is first set to zero, and then the electromagnetic valve IV 14 is closed.

[0063] Example 3

[0064] like Figure 2 As shown, this embodiment provides a hydrogen isotope mass spectrometer using the above-mentioned gas injection system, including an intake system 22, an ECR ion source 23, an accelerating tube 24, a magnetic analyzer 25, an ion detector 27, a data acquisition and processing system, a vacuum system and a control system.

[0065] The mass spectrometer is equipped with 9 Faraday cups 26 to realize 9 beam current measurements of H, D, T, TH, TD, TT, C, N, and O. Two (D and T) Faraday cups 26 are followed by ion detectors 25 to realize simultaneous measurement of elements such as H2 and 3He. The beam current measurement range is 0.01-10μA.

[0066] The mass spectrometer of the present invention, with the cooperation of supporting gas, can greatly reduce and eliminate the interference of molecular particles, with the proportion of monatomic ions reaching up to 90%. Due to the higher energy, it has the ability to identify and exclude molecular ions and isobaric ions, making the measurement more accurate.

[0067] The present invention solves the problem of continuous and stable micro-injection of sample gas in a hydrogen mass spectrometer. By adjusting the valve, 0.01sccm sample gas injection can be achieved, and a small amount of sample is required. The support gas and the sample gas can be mixed and injected in a specific ratio, which inhibits the generation of molecular ions in the ionization process inside the ion source and increases the proportion of hydrogen isotope monoatomic ions. The injection system can realize negative pressure injection to ensure that the sample gas inside the ion source is fully ionized.

[0068] The present invention is provided with a sample recovery bottle, which can recover the excess sample in the gas mixing chamber; the gas intake system can also be used as a sampling device for other gas mass spectrometers, and can realize the mixed sampling of two different gases in proportion. The sampling system has a high level of automation and can cooperate with the client to realize remote control of quantitative continuous sampling of sample gas.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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 hydrogen isotope mass spectrometer intake system, characterized in that: It includes a gas mixing chamber, a sample gas inlet channel, a support gas inlet channel, a sample gas recovery channel, a mixed gas injection channel and a vacuum system, wherein the sample gas inlet channel includes a sample bottle, which is connected to the gas mixing chamber through an air pipe; the support gas inlet channel includes a support gas cylinder, which is connected to the gas mixing chamber through an air pipe; the sample gas recovery channel includes a recovery bottle, which is connected to the gas mixing chamber through an air pipe; the mixed gas injection channel includes an ion source, which is connected to the gas mixing chamber through an air pipe; the vacuum system includes a dry pump, a molecular pump, an ionization gauge and a resistance gauge, the dry pump and the molecular pump are respectively connected to the gas mixing chamber through an air pipe, and the ionization gauge and the resistance gauge are respectively connected to the gas mixing chamber.

2. The hydrogen isotope mass spectrometer gas inlet system according to claim 1, characterized in that: A pressure gauge is provided on the gas mixing chamber.

3. The hydrogen isotope mass spectrometer gas inlet system according to claim 2, characterized in that: A manual valve II and a solenoid valve II are provided on the pipeline between the sample bottle and the gas mixing chamber; a pressure reducing valve I, a solenoid valve I and a manual valve I are provided on the pipeline between the support gas bottle and the gas mixing chamber; a manual valve III and a solenoid valve III are provided on the pipeline between the recovery bottle and the gas mixing chamber.

4. The hydrogen isotope mass spectrometer gas inlet system according to claim 3, characterized in that: A solenoid valve IV and a mass flow controller are provided between the ion source and the gas mixing chamber; a plug valve and a manual valve IV are provided on the connecting pipelines between the dry pump, the molecular pump and the gas mixing chamber.

5. The method for using the hydrogen isotope mass spectrometer intake system according to claim 4, characterized in that: The steps include: S1. First, evacuate the gas mixing chamber; S2, then inject a certain amount of sample gas through the sample gas inlet channel; S3, injecting a set proportion of supporting gas through the supporting gas inlet channel; S4, finally injecting the sample into the ion source through the mixed gas injection channel; S5. Recover excess sample through the sample gas recovery channel.

6. The method for using the hydrogen isotope mass spectrometer intake system according to claim 5, characterized in that: The process of vacuuming the mixing chamber: First, open the dry pump, plug valve, manual valve IV and resistance gauge in sequence, evacuate the gas mixing chamber, and observe the resistance gauge indication. When the vacuum in the gas mixing chamber is lower than 5Pa, turn on the molecular pump to continue evacuating the chamber and turn on the ionization gauge; observe the ionization gauge indication. When the vacuum in the gas mixing chamber is lower than 10-4Pa, close the manual valve IV, plug valve and molecular pump in sequence. When the molecular pump speed is 0, turn off the dry pump and the ionization gauge.

7. The method for using the hydrogen isotope mass spectrometer inlet system according to claim 5, characterized in that: Sample gas pipeline intake process: Open manual valve II and solenoid valve II in sequence, and inject the gas in the sample bottle into the gas mixing chamber through the air pipe. Observe the pressure change in the gas mixing chamber through the pressure gauge. When the pressure reaches the target value, close solenoid valve II and manual valve II in sequence.

8. The method for using the hydrogen isotope mass spectrometer intake system according to claim 5, characterized in that: Support gas intake process: Open the pressure reducing valve, solenoid valve I and manual valve I in sequence, and the supporting gas enters the mixing chamber through the air pipe. Observe the pressure change in the mixing chamber through the pressure gauge. When the pressure value reaches the predetermined target value, close the manual valve I, solenoid valve I and pressure reducing valve in sequence.

9. The method for using the hydrogen isotope mass spectrometer intake system according to claim 5, characterized in that: Mixed gas injection process: Open the solenoid valve IV, set the mass flow controller flow rate, and inject the mixed gas through the gas pipe at a specific flow rate; when the injection is finished, first set the mass flow controller flow rate to zero, and then close the solenoid valve IV.

10. The method for using the hydrogen isotope mass spectrometer intake system according to claim 5, characterized in that: Sample recovery process: Open the solenoid valve III and the manual valve III to recover the excess sample in the gas mixing chamber.

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