Hydrogen isotope gas analysis sample chamber and hydrogen isotope gas measuring device

Abstract

The embodiment of the present application provides a hydrogen isotope gas analysis sample chamber and a hydrogen isotope gas measurement device. The sample chamber includes: a shell, one side of which forms an opening; an exit window, which is sealed at the opening to form a sealed cavity together with the shell, wherein the exit window is made of a material that allows X-rays to penetrate; an air inlet pipeline, which is connected to the sealed cavity and is used to introduce hydrogen isotope gas into the sealed cavity; and a bremsstrahlung target, which is made of a material that can form X-rays with β-rays in the hydrogen isotope gas, and the bremsstrahlung target faces the exit window in the sealed cavity and is spaced apart from the exit window. The embodiment of the present application can improve the conversion efficiency of β-rays to X-rays by separating the bremsstrahlung target from the exit window, and is also beneficial for X-rays to be emitted through the exit window to increase the X-ray count rate detected by the probe, thereby improving the detection capability.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen isotope gas measurement, and in particular to a hydrogen isotope gas analysis sample chamber and a hydrogen isotope gas measurement device. Background Art

[0002] The principle of the beta-induced X-ray (BIX) tritium partial pressure measurement method is that the beta rays released during the spontaneous decay of tritium interact with the metal material (i.e., the bremsstrahlung target) to produce X-rays. By measuring the X-rays and fitting them with the tritium partial pressure to obtain a calibration curve, the tritium partial pressure in the tritium-containing gas can be measured.

[0003] Typically, a tritium partial pressure measurement device consists of a partial pressure sample chamber and a probe. Existing tritium partial pressure measurement devices are generally suitable for measuring the tritium content of high-concentration pure tritium gas, but have insufficient detection capabilities when measuring the tritium content in trace tritium gas. Summary of the Invention

[0004] In response to the above technical problems, the embodiments of the present application provide a hydrogen isotope gas analysis sample chamber and a hydrogen isotope gas measuring device to improve the detection capability of the measuring device.

[0005] In a first aspect, an embodiment of the present application provides a hydrogen isotope gas analysis sample chamber, comprising:

[0006] a housing, wherein an opening is formed on one side of the housing;

[0007] an exit window, sealingly disposed at the opening to form a sealed cavity together with the housing, wherein the exit window is made of a material that allows X-rays to penetrate;

[0008] an air inlet pipeline, communicating with the sealed cavity and used for introducing hydrogen isotope gas into the sealed cavity; and

[0009] The bremsstrahlung target is made of a material capable of forming X-rays with beta rays in hydrogen isotope gas. The bremsstrahlung target faces the exit window in the sealed cavity and is spaced apart from the exit window.

[0010] In a second aspect, an embodiment of the present application provides a hydrogen isotope gas measurement device, comprising the sample chamber described in the first aspect of the present application; and

[0011] A detection cavity is provided with a probe for detecting X-rays, wherein

[0012] The detection cavity is separated from the sealed cavity of the sample chamber by the exit window of the sample chamber.

[0013] The embodiment of the present application can improve the conversion efficiency of β rays into X-rays by separating the bremsstrahlung target from the exit window, and is also beneficial for the X-rays to be emitted through the exit window to increase the X-ray count rate detected by the probe, thereby improving the detection capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other objects and advantages of the present invention will become apparent from the following description of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention.

[0015] Figure 1 is a schematic structural diagram of a hydrogen isotope gas analysis sample chamber according to one embodiment of the present invention;

[0016] Figure 2 is a schematic structural diagram of a housing 10 according to an embodiment of the present invention;

[0017] Figure 3 is a schematic structural diagram of a hydrogen isotope gas measuring device according to an embodiment of the present invention; and

[0018] Figure 4 This is a curve of the change of the inlet end T abundance with the number of reflux cycles obtained by analyzing using the measuring device of an embodiment of the present application.

[0019] It should be noted that the drawings are not necessarily drawn to scale, but are merely shown in a schematic manner that does not affect the reader's understanding. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiment is only one embodiment of the present invention, not all embodiments. Based on the described embodiment 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.

[0021] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application should have the common meanings understood by persons having ordinary skills in the field to which the invention belongs.

[0022] In the description of the embodiments of the present invention, “a plurality of” means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0023] See also Figure 1 The hydrogen isotope gas analysis sample chamber (hereinafter referred to as the sample chamber) according to an embodiment of the present invention includes: a housing 10 , an exit window 20 , an air inlet pipe 30 , and a bremsstrahlung target 40 .

[0024] An opening 11 is formed at one side of the housing 10. An exit window 20 is sealingly disposed at the opening 11 to form a sealed cavity 101 together with the housing 10. The exit window 20 is made of a material that allows X-rays to penetrate.

[0025] The air inlet pipe 30 is in communication with the sealed cavity 101 and is used to introduce hydrogen isotope gas into the sealed cavity 101 .

[0026] The Bremsstrahlung target 40 is made of a material that can generate X-rays with β-rays in the hydrogen isotope gas. The Bremsstrahlung target 40 may also be referred to as a Bremsstrahlung X-ray generator.

[0027] In the related art, the bremsstrahlung target is typically coated on the exit window 20 in the form of a thin film. The inventors of the present application have discovered that separating the bremsstrahlung target from the exit window 20 can improve the conversion efficiency of beta rays into X-rays, and also facilitates the emission of X-rays through the exit window 20, thereby increasing the X-ray count rate detected by the probe and thus improving detection capabilities.

[0028] Therefore, in the embodiment of the present application, the bremsstrahlung target 40 is particularly disposed in the sealed cavity 101, facing the exit window 20 and spaced apart from the exit window 20. In other words, in the embodiment of the present application, the bremsstrahlung target 40 is parallel to the exit window 20 and spaced apart from the exit window 20.

[0029] Since the embodiment of the present application can improve the conversion efficiency of β rays into X-rays and increase the X-ray counting rate detected by the probe, the measuring device of the embodiment of the present application can measure the tritium content in trace tritium gas.

[0030] The inventors of this application have further discovered that the spacing between the bremsstrahlung target 40 and the exit window 20 significantly affects the conversion efficiency of beta rays into bremsstrahlung X-rays. Therefore, in a further embodiment, the spacing between the bremsstrahlung target 40 and the exit window 20 is 1.5 mm to 5 mm. When the spacing between the bremsstrahlung target 40 and the exit window 20 is within this range, the conversion efficiency of beta rays into bremsstrahlung X-rays is high.

[0031] In a further embodiment, the spacing between the bremsstrahlung target 40 and the exit window 20 is 2.5 mm to 3.5 mm. When the spacing between the bremsstrahlung target 40 and the exit window 20 is within this range, the conversion efficiency of beta rays to bremsstrahlung X-rays can be further improved, and the tritium partial pressure detection limit can be reduced to 1 Pa. In some embodiments, the spacing between the bremsstrahlung target 40 and the exit window 20 can be 3 mm.

[0032] In some embodiments, the material of the bremsstrahlung target 40 may be one or more of gold, tungsten, and nickel. In some embodiments, the bremsstrahlung target 40 is made of gold.

[0033] The exit window 20 can be made of beryllium. It will be readily understood that the exit window 20 is not provided with any other material capable of reacting with the beta rays in the hydrogen isotope gas to form X-rays. The thickness of the exit window 20 (i.e., the beryllium window) can be 0.25 mm to 0.35 mm. In some embodiments, the beryllium window can be 0.3 mm thick.

[0034] In some embodiments, a gold film is formed on the inner wall of the housing 10. The thickness of the gold film is no less than 60 nm. For example, the thickness of the gold film ranges from 60 nm to 200 nm. The gold film reduces the adsorption of gaseous tritium on the inner wall of the sealed chamber 101, thereby reducing the memory effect. Experimental testing has shown that when the gold film is applied to the sealed chamber 101, the background value increase does not exceed 5% over 100 hours of continuous measurement.

[0035] In some embodiments, the thickness of the Bremsstrahlung target 40 is greater than the thickness of the gold film. The thickness of the Bremsstrahlung target 40 can be in the micrometer range, for example, 5 μm to 50 μm. In some embodiments, the thickness of the Bremsstrahlung target 40 is 20 μm.

[0036] In some embodiments, the bremsstrahlung target 40 may be supported by the inner wall of the sealed cavity 101 .

[0037] In some embodiments, the sample chamber further includes a support frame 41 for providing support for the bremsstrahlung target 40 .

[0038] The support frame 41 faces the side of the bremsstrahlung target 40 that faces away from the exit window 20. In some embodiments, the exit window 20 can serve as the top wall of the sealed cavity 101, and the bremsstrahlung target 40 is only placed above the support frame 41 and supported by the support frame 41.

[0039] In some embodiments, the housing 10 includes a cylindrical section 12 forming an opening 11, a conical section 14 extending away from the opening 11 and having a gradually decreasing inner diameter, and an annular section 15 connected between the cylindrical section 12 and the conical section 14, wherein a side port of the conical section 14 away from the conical section 14 is connected to the air intake line 30.

[0040] In related art, the sample chamber is large and contains a large dead volume, resulting in poor real-time tracking performance when measuring hydrogen isotope gases. The present embodiment, by configuring the housing 10 to include a cylindrical section 12, an annular section 15, and a conical section 14, can reduce the volume of the sealed chamber 101 while also reducing the dead volume. This allows the probe 70 to respond quickly, thus providing gas flow dynamic analysis capabilities. This allows the sample chamber of the present embodiment to function as a gas flow analysis sample chamber, thereby improving the real-time tracking and real-time online measurement capabilities of the hydrogen isotope gas measurement device.

[0041] In addition, it is easy to understand that for the housing 10 with the above structure, the axis of its air inlet duct 30 is the same as that of the exit window 20, and it is a straight-through design. For the housing 10 with the above structure, the inner diameter of its sealed cavity 101 gradually decreases from the exit window 20 to the air inlet duct 30. Such a design, on the one hand, maximizes the area of ​​the exit window 20 to maximize the X-rays to be emitted through the exit window 20 and detected by the probe; on the other hand, it minimizes the volume of the sealed cavity 101 and minimizes the dead volume. In some embodiments, the sum of the heights of the cylindrical segment 12, the annular segment 15, and the conical segment 14 is less than the inner diameter of the cylindrical segment 12, thereby maximizing the area of ​​the exit window 20 and minimizing the volume of the sealed cavity 101.

[0042] In some embodiments, the inner diameter of cylindrical section 12 is 10-15 mm. This allows the volume of sealed cavity 101 formed between housing 10 and the measurement window to be reduced to 3 ml. In such embodiments, due to the very small volume of sealed cavity 101, the sample chamber can be used as a sample chamber for gas flow analysis.

[0043] In some embodiments, the cylindrical segment 12 , the annular segment 15 , the conical segment 14 and the air intake pipe 30 are welded to each other.

[0044] In some embodiments, the cylindrical segment 12, the annular segment 15, the conical segment 14 and the air intake pipe 30 are formed as an integral part. The integral part can be formed by a straight flange.

[0045] The support frame 41 may be disposed on the annular segment 15 . In some embodiments, the inner surface of the annular segment 15 is recessed downward to form an annular platform 151 , and the support frame 41 is supported by the annular platform 151 .

[0046] In some embodiments, the housing 10 is provided with a mounting hole 16, and another flange 60 can be used to seal the exit window 20 to the housing 10. Specifically, the housing 10 and the flange 60 are tightened by fasteners 50, and the polytetrafluoroethylene seal 80 is used to make the sealed cavity 101 vacuum-tight.

[0047] Based on the above, it can be seen that the sample chamber in the embodiment of the present application, in combination with the probe, can realize real-time online accurate quantitative analysis of the X content in hydrogen isotope gas.

[0048] The present application also provides a hydrogen isotope gas measuring device (hereinafter referred to as the measuring device). Figure 3 The measuring device of the embodiment of the present application includes: the sample chamber and detection cavity of any embodiment of the present application.

[0049] A probe 70 for detecting X-rays is provided in the detection chamber, wherein the detection chamber is separated from the sealed chamber 101 of the sample chamber by the sample chamber exit window 20. The probe 70 may be a NaI probe.

[0050] In some embodiments, the measuring device further includes: a flange 60, an exit window 20 installed between the flange 60 and the housing 10, the flange 60 defines at least part of the peripheral wall of the detection cavity, and the exit window 20 defines one side end wall of the detection cavity.

[0051] See also Figure 4 The probe 70 is located radially inward of the flange 60 and is clearance-matched with the inner wall of the flange 60. The measuring device may further include other sealing members that cooperate with the flange 60 to seal the probe 70 in the detection cavity.

[0052] During the hydrogen isotope enrichment process, the heating and desorption at the fore-column inlet and the cooling and re-absorption of gases are performed in a flow-type manner. Abundance data is a key criterion for the enrichment process. The measurement device that analyzes changes in hydrogen isotope abundance at the separation column inlet requires rapid response and strong dynamic tracking capabilities.

[0053] During the hydrogen isotope enrichment process, after a certain feed, the curve of the change of the inlet T abundance with the number of reflux cycles obtained by analyzing the measuring device of the embodiment of the present application is shown in FIG. Figure 4 In the test, the test pressure does not exceed 10kPa, and the abundance of the initial feed raw gas is about 1.35%. Figure 4 It can be seen that after the feed, the inlet abundance gradually decreased after seven reflux cycles, reaching a detectable abundance of 0.01%, corresponding to a partial pressure of 1 Pa. In the lean material extraction process, where the abundance data provides process criteria, the lean material abundance met the project's expected standards.

[0054] This demonstrates that the measurement device of the present embodiment can analyze changes in hydrogen isotope abundance at the separation column inlet during the hydrogen isotope enrichment process. This also confirms that the sample chamber of the present embodiment is capable of real-time online measurement and can serve as a flow analysis sample chamber.

[0055] Regarding the embodiments of the present invention, it should also be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0056] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A hydrogen isotope gas analysis sample chamber, characterized in that: include: A housing, wherein one side of the housing forms an opening; an exit window, sealingly disposed at the opening to form a sealed cavity together with the housing, wherein the exit window is made of a material that allows X-rays to penetrate; an air inlet pipeline, connected to the sealed cavity, and used for introducing hydrogen isotope gas into the sealed cavity; a bremsstrahlung target piece, made of a material capable of forming X-rays with beta rays in hydrogen isotope gas, the bremsstrahlung target piece facing the exit window in the sealed cavity and spaced apart from the exit window; A support frame, used for providing support for the bremsstrahlung target; The housing comprises a cylindrical section forming the opening, a conical section extending in a direction away from the opening and having a gradually decreasing inner diameter, and an annular section connected between the cylindrical section and the conical section, wherein a port on one side of the conical section away from the conical section is in communication with the air intake pipeline; The support frame is arranged on the annular segment.

2. The sample chamber according to claim 1, characterized in that: The bremsstrahlung target is made of gold.

3. The sample chamber according to claim 1, characterized in that: The distance between the bremsstrahlung target and the exit window is 1.5 mm to 5 mm.

4. The sample chamber according to claim 1, characterized in that: The exit window is made of beryllium.

5. The sample chamber according to claim 1, characterized in that: The inner wall of the housing is formed with a gold film.

6. The sample chamber according to claim 5, characterized in that: The thickness of the bremsstrahlung target is greater than the thickness of the gold film.

7. The sample chamber according to claim 1, characterized in that: The support frame faces a side surface of the bremsstrahlung target piece which is opposite to the exit window.

8. The sample chamber according to claim 1, characterized in that: The cylindrical segment, the annular segment, the conical segment and the air intake pipeline are integrally formed.

9. The sample chamber according to claim 1, characterized in that: The sum of the heights of the cylindrical segment, the annular segment and the conical segment is smaller than the inner diameter of the cylindrical segment.

10. The sample chamber according to claim 1, characterized in that: The inner diameter of the cylindrical section is 10-15 mm.

11. A hydrogen isotope gas measuring device, characterized in that: include: The sample chamber according to any one of claims 1 to 10; and A detection cavity is provided with a probe for detecting X-rays, wherein The detection cavity is separated from the sealed cavity of the sample chamber by the exit window of the sample chamber.

12. The measuring device according to claim 11, characterized in that Also includes: The flange, the exit window is installed between the flange and the shell, the flange defines at least a portion of the peripheral wall of the detection cavity, and the exit window defines a side end wall of the detection cavity.

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