A neutron measuring device for a helium-4 proportional counter

Abstract

This invention discloses a neutron measurement device using a helium-4 proportional counter tube, comprising: a helium-4 proportional counter tube, a proportional counter tube with helium-4 as the main gas and an internal gas pressure greater than or equal to 1 MPa, serving as a neutron detector and used to generate ionized particles; a neutron moderation collimator, enclosing the helium-4 proportional counter tube, used to scatter and moderate neutrons generated by its line-of-sight nuclear fusion device to achieve a collimation effect; an amplifier, used to amplify the output signal of the helium-4 proportional counter tube; a pulse height analyzer, used to receive the amplified output signal and output a pulse height spectrum; and a calculation module, used to receive the pulse height spectrum and fit the pulse height spectrum based on predetermined deuterium-deuterium neutron response energy spectra and deuterium-tritium neutron response energy spectra to obtain the ratio of the proportion of deuterium-deuterium neutrons to the proportion of deuterium-tritium neutrons in the output of the pulse height analyzer, and to calculate the ratio of deuterium-deuterium neutrons to deuterium-tritium neutrons. This invention does not rely on a photomultiplier tube, and the device is not easily affected by interference.

Description

Technical Field

[0001] This invention relates to the field of nuclear fusion research, specifically to a neutron measuring device using a helium-4 proportional counter tube. Background Technology

[0002] In the field of nuclear fusion research, the deuterium-tritium fusion reaction has a large cross-section, and is therefore considered the most promising for realizing the application of fusion energy. However, due to the scarcity of tritium, existing fusion research devices mostly use deuterium for experiments. Although the deuterium-deuterium reaction has a smaller cross-section, one branch of the deuterium-deuterium reaction produces tritium. When tritium accumulates to a certain level in the device, deuterium-tritium fusion will also occur. One branch of the deuterium-deuterium reaction produces neutrons with an average energy of about 2.4 MeV, while the average energy of neutrons produced by the deuterium-tritium reaction is about 14 MeV. To confirm the occurrence of the deuterium-tritium reaction, existing methods include measuring deuterium-tritium neutrons using neutron activation methods. Activation reactions include... 27 Al(n,α) 24 Na, its reaction threshold is 3.25 MeV, or 63 Cu(n,2n) 62 Cu has a reaction threshold of 11 MeV. However, the activation method cannot provide timing information for the production of deuterium-tritium neutrons. Another approach is to use a scintillator to measure deuterium-tritium neutrons. When a neutron enters the scintillator, it undergoes elastic scattering with the nuclei within, producing recoil nuclei. By measuring the energy of these recoil nuclei, the neutron energy can be obtained, thus distinguishing between deuterium-tritium neutrons and deuterium-deuterium neutrons. However, scintillator luminescence measurements require photomultiplier tubes, which are susceptible to interference in the high magnetic fields of nuclear fusion devices.

[0003] In view of the above, this application is hereby submitted. Summary of the Invention

[0004] In order to measure neutrons and distinguish between deuterium-deuterium and deuterium-tritium neutrons in nuclear fusion devices, this invention provides a neutron measuring device with a helium-4 proportional counter tube. It can measure the time evolution of deuterium-tritium neutrons in a deuterium-deuterium fusion environment. At the same time, since it does not rely on a photomultiplier tube, the device is not easily affected by interference.

[0005] This invention is achieved through the following technical solution:

[0006] A neutron measuring device using a helium-4 proportional counter tube, the neutron measuring device comprising:

[0007] Helium-4 proportional counter tube: A proportional counter tube with helium-4 as the main gas and an internal pressure greater than or equal to 1 MPa. It is used as a neutron detector and to generate ionized particles.

[0008] A neutron moderation collimator, which encloses the helium-4 proportional counter tube, is used to scatter and moderate neutrons produced by its out-of-line-of-sight nuclear fusion device to achieve a collimation effect.

[0009] An amplifier is used to amplify the output signal of the helium-4 proportional counter tube;

[0010] A pulse height analyzer is used to receive the amplified output signal and output a pulse height spectrum.

[0011] The calculation module is used to receive the pulse height spectrum, fit the pulse height spectrum based on the predetermined deuterium-deuterium neutron response energy spectrum and deuterium-tritium neutron response energy spectrum, obtain the ratio of the proportion of deuterium-deuterium neutrons and the proportion of deuterium-tritium neutrons in the output of the pulse height analyzer, and calculate the ratio of deuterium-deuterium neutrons to deuterium-tritium neutrons produced by the nuclear fusion device.

[0012] As a further preferred embodiment, the main gas also includes a heavy inert gas.

[0013] As a further preferred option, the heavy inert gas is one or more of argon, krypton, and xenon.

[0014] As a further preferred embodiment, the neutron moderating material of the neutron moderating collimator is polyethylene with a thickness of 5 cm or more.

[0015] As a further preferred embodiment, the ratio of deuterium-deuterium neutrons to deuterium-tritium neutrons is k / f, where f is a predetermined detection efficiency ratio and k is the ratio of the proportion of deuterium-deuterium neutrons to the proportion of deuterium-tritium neutrons in the pulse height analyzer output.

[0016] As a further preferred embodiment, the process for determining the predetermined detection efficiency ratio is as follows:

[0017] The deuterium-deuterium neutrons with energies of 2 MeV to 3 MeV in the neutron distribution region of the nuclear fusion device were measured in advance to determine the deuterium-deuterium neutron response energy spectrum and the first detection efficiency f1;

[0018] The deuterium-tritium neutrons with energies of 13 MeV to 15 MeV in the neutron distribution region of the nuclear fusion device were measured in advance to determine the deuterium-tritium neutron response energy spectrum and the second detection efficiency f2;

[0019] Based on the first detection efficiency f1 and the second detection efficiency f2, the ratio of detection efficiencies f = f1 / f2 is determined.

[0020] As a further preferred embodiment, the neutron measuring device also includes a DC high-voltage power supply and a DC low-voltage power supply;

[0021] The high-voltage DC power supply is used to provide bias voltage to the helium-4 proportional counter tube to collect ionized particles generated inside the helium-4 proportional counter tube;

[0022] The DC low-voltage power supply is used to power the amplifier.

[0023] As a further preferred option, the least squares method is used to fit the pulse height spectrum based on the predetermined deuterium-deuterium neutron response energy spectrum and deuterium-tritium neutron response energy spectrum.

[0024] As a further preferred embodiment, the neutron measuring device is adapted to measure the time evolution of deuterium-deuterium neutrons and the time evolution of deuterium-tritium neutrons.

[0025] As a further preferred embodiment, multiple of these neutron measuring devices are arranged in an array, adapted to measure the spatial distribution of deuterium-deuterium fusion neutrons in a nuclear fusion device, as well as the spatial distribution of deuterium-tritium fusion neutrons.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] The present invention discloses a neutron measurement device based on a helium-4 proportional counter tube, comprising a helium-4 proportional counter tube, a neutron moderation collimator, an amplifier, a pulse height analyzer, and a calculation module. It can measure the time evolution of deuterium-tritium neutrons in a deuterium-deuterium fusion environment. Furthermore, since it does not rely on a photomultiplier tube, the device is not easily affected by interference. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0029] Figure 1 This is a schematic diagram of the structure of a neutron measuring device using a helium-4 proportional counter tube according to the present invention.

[0030] Figure reference numerals and corresponding component names:

[0031] 01-Nuclear fusion device, 02-Neutron distribution region, 03-Neutron moderation collimator, 04-Helium-4 proportional counter tube, 05-Amplifier, 06-Pulse height analyzer, 07-Calculation module, 08-DC low-voltage power supply, 09-DC high-voltage power supply. Detailed Implementation

[0032] In the following, the terms “comprising” or “may include” as used in various embodiments of the invention indicate the presence of an inventive function, operation, or element, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in various embodiments of the invention, the terms “comprising,” “having,” and their cognates are intended only to indicate a specific feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or adding one or more combinations of the foregoing.

[0033] In various embodiments of the invention, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0034] The expressions used in the various embodiments of the present invention (such as "first," "second," etc.) may modify various constituent elements in the various embodiments, but do not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used for the purpose of distinguishing one element from other elements. For example, a first user device and a second user device refer to different user devices, although both are user devices. For example, a first element may be referred to as a second element without departing from the scope of the various embodiments of the present invention, and similarly, a second element may also be referred to as a first element.

[0035] It should be noted that if a description is made of "connecting" one component to another, then the first component can be directly connected to the second component, and a third component can be "connected" between the first and second components. Conversely, when a component is "directly connected" to another component, it can be understood that there is no third component between the first and second components.

[0036] The terminology used in the various embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the invention pertain. The terms (such as those defined in a generally used dictionary) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of the invention.

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0038] Example 1

[0039] like Figure 1 As shown in the figure, this embodiment is a neutron measuring device using a helium-4 proportional counter tube. The present invention utilizes a helium-4 proportional counter tube to measure neutrons and distinguish between deuterium-deuterium and deuterium-tritium neutrons.

[0040] The neutron measuring device includes a helium-4 proportional counter tube 04, a neutron moderation collimator 03, an amplifier 05, a pulse height analyzer 06, and a calculation module 07, wherein:

[0041] The Helium-4 proportional counter tube 04 is a proportional counter tube with helium-4 and heavy inert gas as the main gases. Its internal gas pressure is greater than or equal to 1 MPa (i.e., its internal gas pressure is 1 MPa or higher). The Helium-4 proportional counter tube 04 is used as a neutron detector and to generate ionized particles.

[0042] A neutron moderator collimator 03 encloses the helium-4 proportional counter tube 04. The neutron moderator collimator 03 is composed of common neutron moderator materials such as polyethylene, with a thickness of 5 cm or more. The neutron moderator collimator 03 is used to scatter and moderate the neutrons produced by the nuclear fusion device 01 outside its line of sight, thereby achieving a collimation effect. The nuclear fusion device 01 produces a neutron distribution region 02.

[0043] Amplifier 05 is used to amplify the output signal of the helium-4 proportional counter tube 04;

[0044] Pulse height analyzer 06 is used to receive the amplified output signal and output the pulse height spectrum;

[0045] The calculation module 07 is used to receive the pulse height spectrum output by the pulse height analyzer 06, and fit the pulse height spectrum output by the pulse height analyzer 06 based on the predetermined deuterium-deuterium neutron response energy spectrum and deuterium-tritium neutron response energy spectrum to obtain the ratio of the proportion of deuterium-deuterium neutrons and the proportion of deuterium-tritium neutrons in the output of the pulse height analyzer 06, and calculate the ratio of deuterium-deuterium neutrons to deuterium-tritium neutrons generated by the nuclear fusion device 01.

[0046] As a further implementation, the heavy inert gas is one or more of argon, krypton, and xenon.

[0047] As a further implementation, the helium-4 proportional counter contains a trace amount of helium-3, and the system energy is calibrated using the reaction energy of helium-3 with thermal neutrons. The thermal neutron source can be easily obtained through a neutron source and a moderator.

[0048] As a further implementation, the ratio of deuterium-deuterium neutrons to deuterium-tritium neutrons calculated by the calculation module 07 is k / f, where f is a predetermined detection efficiency ratio and k is the ratio of the proportion of deuterium-deuterium neutrons to the proportion of deuterium-tritium neutrons in the output of the pulse height analyzer 06.

[0049] As a further implementation, the least squares method is used to fit the pulse height spectrum based on the predetermined deuterium-deuterium neutron response energy spectrum and deuterium-tritium neutron response energy spectrum.

[0050] As a further implementation, the neutron measuring device also includes a DC high-voltage power supply 09 and a DC low-voltage power supply 08;

[0051] The high-voltage DC power supply 09 is used to provide bias voltage to the helium-4 proportional counter tube 04 to collect ionized particles generated inside the helium-4 proportional counter tube 04;

[0052] The DC low-voltage power supply 08 is used to power amplifier 05.

[0053] In practice, the neutron moderator collimator 03 is a horizontally placed cylinder with a through hole drilled in its axis. One end face of the helium-4 proportional counter tube 04 is aligned with the right end face of the neutron moderator collimator 03. The measurement process is as follows: First, neutrons generated by the nuclear fusion device 01 are distributed in the neutron distribution region 02, and are scattered and slowed down by the neutron moderation collimator 03. Second, the above neutrons are detected by the helium-4 proportional counter tube 04 as a neutron detector, and ionized particles are generated. Then, the output signal of the helium-4 proportional counter tube 04 is amplified by the amplifier 05. The amplified output signal is received by the pulse height analyzer 06, and a pulse height spectrum is output. Finally, the pulse height spectrum output by the pulse height analyzer 06 is received by the calculation module 07, and the pulse height spectrum output by the pulse height analyzer 06 is fitted based on the predetermined deuterium-deuterium neutron response energy spectrum and deuterium-tritium neutron response energy spectrum to obtain the ratio of the proportion of deuterium-deuterium neutrons and the proportion of deuterium-tritium neutrons in the output of the pulse height analyzer 06, and the ratio of deuterium-deuterium neutrons to deuterium-tritium neutrons generated by the nuclear fusion device 01 is calculated.

[0054] This invention enables the measurement of the time evolution of deuterium-tritium neutrons in a deuterium-deuterium fusion environment, and because it does not rely on photomultiplier tubes, the device is less susceptible to interference.

[0055] The neutron measuring device of this invention is suitable for measuring the proportion of deuterium-deuterium fusion neutrons or deuterium-tritium fusion neutrons in fusion devices, and is particularly suitable for detecting the generation of deuterium-tritium fusion neutrons in fusion devices. This invention is also suitable for measuring the temporal evolution of deuterium-deuterium neutrons, as well as the temporal evolution of deuterium-tritium neutrons. In particular, an array of multiple such neutron measuring devices is suitable for measuring the spatial distribution of deuterium-deuterium fusion neutrons, as well as the spatial distribution of deuterium-tritium fusion neutrons, in nuclear fusion devices.

[0056] Example 2

[0057] The difference between this embodiment and Embodiment 1 is that this embodiment also provides a process for determining a predetermined detection efficiency ratio. The process for determining the predetermined detection efficiency ratio is as follows:

[0058] The deuterium-deuterium neutrons with energies of 2 MeV to 3 MeV in the neutron distribution region 02 of the nuclear fusion device 01 were measured in advance to determine the deuterium-deuterium neutron response energy spectrum and the first detection efficiency f1;

[0059] The deuterium-tritium neutrons with energies of 13 MeV to 15 MeV in the neutron distribution region 02 of the nuclear fusion device 01 were measured in advance to determine the deuterium-tritium neutron response energy spectrum and the second detection efficiency f2.

[0060] Based on the first detection efficiency f1 and the second detection efficiency f2, the ratio of detection efficiencies f = f1 / f2 is determined.

[0061] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0062] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0063] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0064] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0065] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A neutron measuring device using a helium-4 proportional counter tube, characterized in that, The neutron measuring device includes: Helium-4 proportional counter (04), a proportional counter tube with helium-4 as the main gas, with an internal gas pressure greater than or equal to 1 MPa, is used as a neutron detector and to generate ionized particles. The neutron moderator collimator (03) encloses the helium-4 proportional counter tube (04) to scatter and moderate the neutrons produced by its out-of-line-of-sight nuclear fusion device (01) to achieve collimation; Amplifier (05) is used to amplify the output signal of the helium-4 proportional counter tube (04); The pulse height analyzer (06) is used to receive the amplified output signal and output the pulse height spectrum; The calculation module (07) is used to receive the pulse height spectrum and fit the pulse height spectrum based on the predetermined deuterium-deuterium neutron response energy spectrum and deuterium-tritium neutron response energy spectrum to obtain the ratio of the proportion of deuterium-deuterium neutrons and the proportion of deuterium-tritium neutrons in the output of the pulse height analyzer (06), and calculate the ratio of deuterium-deuterium neutrons to deuterium-tritium neutrons generated by the nuclear fusion device (01).

2. The neutron measuring device with a helium-4 proportional counter tube according to claim 1, characterized in that, The main gas also includes heavy inert gases.

3. The neutron measuring device with a helium-4 proportional counter tube according to claim 2, characterized in that, The heavy inert gas is one or more of argon, krypton, and xenon.

4. The neutron measuring device with a helium-4 proportional counter tube according to claim 1, characterized in that, The neutron moderating material of the neutron moderating collimator (03) is polyethylene, and the thickness of the neutron moderating collimator (03) is greater than or equal to 5 cm.

5. The neutron measuring device with a helium-4 proportional counter tube according to claim 1, characterized in that, The ratio of deuterium-deuterium neutrons to deuterium-tritium neutrons is k / f, where f is a predetermined detection efficiency ratio and k is the ratio of the proportion of deuterium-deuterium neutrons to the proportion of deuterium-tritium neutrons in the output of the pulse height analyzer (06).

6. The neutron measuring device for a helium-4 proportional counter tube according to claim 5, characterized in that, The process for determining the predetermined detection efficiency ratio is as follows: The deuterium-deuterium neutrons with energies of 2 MeV to 3 MeV in the neutron distribution region (02) of the nuclear fusion device (01) are measured in advance to determine the deuterium-deuterium neutron response energy spectrum and the first detection efficiency f1; The deuterium-tritium neutrons with energies of 13 MeV to 15 MeV in the neutron distribution region (02) of the nuclear fusion device (01) are measured in advance to determine the deuterium-tritium neutron response energy spectrum and the second detection efficiency f2; Based on the first detection efficiency f1 and the second detection efficiency f2, the ratio of detection efficiencies f = f1 / f2 is determined.

7. The neutron measuring device for a helium-4 proportional counter tube according to claim 1, characterized in that, The neutron measuring device also includes a DC high-voltage power supply (09) and a DC low-voltage power supply (08); The DC high voltage power supply (09) is used to provide bias voltage to the helium-4 proportional counter tube (04) to collect ionized particles generated inside the helium-4 proportional counter tube (04); The DC low-voltage power supply (08) is used to power the amplifier (05).

8. The neutron measuring device for a helium-4 proportional counter tube according to claim 1, characterized in that, The pulse height spectrum is fitted using the least squares method based on the predetermined deuterium-deuterium neutron response energy spectrum and deuterium-tritium neutron response energy spectrum.

9. A neutron measuring device using a helium-4 proportional counter tube according to claim 1, characterized in that, This neutron measuring device is adapted to measure the time evolution of deuterium-deuterium neutrons, as well as the time evolution of deuterium-tritium neutrons.

10. A neutron measuring device using a helium-4 proportional counter tube according to claim 1, characterized in that, An array of multiple neutron measuring devices is adapted to measure the spatial distribution of deuterium-deuterium fusion neutrons in nuclear fusion devices, as well as the spatial distribution of deuterium-tritium fusion neutrons.

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