Neutron measuring device of helium-4 proportional counter tube

Abstract

The invention discloses a neutron measurement device of a helium-4 proportional counter tube, which comprises a helium-4 proportional counter tube and a proportional counter tube taking helium-4 as a main gas, the internal air pressure of which is greater than or equal to 1Mpa, and the neutron measurement device is used as a neutron detector and is used for generating ionized particles; the neutron moderation collimation body wraps the helium-4 proportional counter tube and is used for scattering and moderating neutrons generated by the nuclear fusion device outside the sight of the neutron moderation collimation body so as to realize a collimation effect; the amplifier is used for amplifying an output signal of the helium-4 proportional counter tube; the pulse height analyzer is used for receiving the amplified output signal and outputting a pulse height spectrum; and the calculation module is used for receiving the pulse height spectrum, fitting the pulse height spectrum based on a predetermined deuterium-deuterium neutron response energy spectrum and a predetermined deuterium-tritium neutron response energy spectrum, obtaining the ratio of the share of deuterium-deuterium neutrons to the share of deuterium-tritium neutrons in the output of the pulse height analyzer, and calculating the ratio of the deuterium-deuterium neutrons to the deuterium-tritium neutrons. The device does not depend on a photomultiplier, and is not liable to be interfered.

Description

Technical Field

[0001] The invention relates to the field of nuclear fusion research, and in particular to a neutron measuring device for a helium-4 proportional counter tube. Background Art

[0002] In the field of nuclear fusion research, the deuterium-tritium fusion reaction has a larger cross section, so it is considered to be the most promising for the application of fusion energy. However, due to the scarcity of tritium, existing fusion research devices mostly use deuterium for experiments. Although the cross section of the deuterium-deuterium reaction is small, a branch of the deuterium-deuterium reaction will produce tritium. When tritium accumulates to a certain level in the device, deuterium-tritium fusion will also occur. One branch of the deuterium-deuterium reaction will produce neutrons with an average energy of about 2.4MeV, while the average energy of neutrons produced by the deuterium-tritium reaction is about 14MeV. In order to confirm the production of the deuterium-tritium reaction, existing methods include measuring deuterium-tritium neutrons using the neutron activation method. Activation reactions include 27 Al(n,α) 24 Na, which has a reaction threshold of 3.25 MeV, or 63 Cu(n,2n) 62 Cu, whose reaction threshold is 11MeV. However, the activation method cannot provide time information of the production of deuterium-tritium neutrons. Another method is to use a scintillator to measure deuterium-tritium neutrons. When a neutron enters a scintillator, it will elastically scatter with the atomic nuclei therein to produce a recoil nucleus. By measuring the energy of the recoil nucleus, the neutron energy can be obtained, thereby distinguishing deuterium-tritium neutrons from deuterium-deuterium neutrons. However, scintillator luminescence measurement requires the use of a photomultiplier tube, which is easily disturbed in the high magnetic field of a nuclear fusion device.

[0003] In view of this, this application is hereby filed. Summary of the invention

[0004] In order to measure neutrons and distinguish deuterium-deuterium and deuterium-tritium neutrons in a nuclear fusion device, the present invention provides a neutron measurement device of a helium-4 proportional counter tube, which 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 disturbed.

[0005] The present invention is achieved through the following technical solutions:

[0006] A neutron measuring device for 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, with an internal gas pressure greater than or equal to 1Mpa, used as a neutron detector and to generate ionized particles;

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

[0009] An amplifier, used for amplifying the output signal of the helium-4 proportional counter tube;

[0010] A pulse height analyzer, for receiving the amplified output signal and outputting a pulse height spectrum;

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

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

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

[0014] As a further preference, the neutron moderating material of the neutron moderating collimator is polyethylene, and the thickness is greater than or equal to 5 cm.

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

[0016] As a further preference, the process of determining the predetermined detection efficiency ratio is:

[0017] Preliminarily measuring deuterium-deuterium neutrons with energies of 2MeV to 3MeV in the neutron distribution area of ​​the nuclear fusion device to determine the deuterium-deuterium neutron response energy spectrum and the first detection efficiency f1;

[0018] Preliminarily measuring deuterium-tritium neutrons with energies of 13 MeV to 15 MeV in the neutron distribution area of ​​the nuclear fusion device to determine the deuterium-tritium neutron response energy spectrum and the second detection efficiency f2;

[0019] According to the first detection efficiency f1 and the second detection efficiency f2, a detection efficiency ratio f=f1 / f2 is determined.

[0020] As a further preference, the neutron measurement device further 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 a bias voltage to the helium-4 proportional counter tube to collect ionized particles generated in the helium-4 proportional counter tube;

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

[0023] As a further preference, the pulse height spectrum is fitted based on a predetermined deuterium-deuterium neutron response energy spectrum and a deuterium-tritium neutron response energy spectrum by using a least square method.

[0024] As a further preference, 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 preference, a plurality of the neutron measuring devices form an array, which is suitable for measuring the spatial distribution of deuterium-deuterium fusion neutrons and the spatial distribution of deuterium-tritium fusion neutrons in a nuclear fusion device.

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

[0027] The invention discloses a neutron measuring device of 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. The device can measure the time evolution of deuterium-tritium neutrons in a deuterium-deuterium fusion environment, and is not easily disturbed because it does not rely on a photomultiplier tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0029] Figure 1 The present invention is a schematic structural diagram of a neutron measuring device for a helium-4 proportional counter tube.

[0030] Reference numerals and corresponding component names:

[0031] 01-nuclear fusion device, 02-neutron distribution area, 03-neutron moderation collimator, 04-helium-4 proportional counter tube, 05-amplifier, 06-pulse height analyzer, 07-computing module, 08-DC low-voltage power supply, 09-DC high-voltage power supply. DETAILED DESCRIPTION

[0032] Hereinafter, the term "include" or "may include" used in various embodiments of the present invention indicates the presence of the invented function, operation or element, and does not limit the addition of one or more functions, operations or elements. In addition, as used in various embodiments of the present invention, the terms "include", "have" and their cognates are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the presence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

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

[0034] The expressions (such as "first", "second", etc.) used in various embodiments of the present invention may modify the various constituent elements in various embodiments, but may 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 an element from other elements. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, without departing from the scope of various embodiments of the present invention, the first element may be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0035] It should be noted that if it is described that one component element is “connected” to another component element, the first component element may be directly connected to the second component element, and a third component element may be “connected” between the first component element and the second component element. Conversely, when one component element is “directly connected” to another component element, it can be understood that there is no third component element between the first component element and the second component element.

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

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description 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, this embodiment is a neutron measurement device of a helium-4 proportional counter tube. The present invention uses a helium-4 proportional counter tube to measure neutrons and distinguish deuterium-deuterium and deuterium-tritium neutrons.

[0040] The neutron measuring device comprises 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] Helium 4 proportional counter tube 04, a proportional counter tube using helium 4 and heavy noble gas as main gases, whose internal gas pressure is greater than or equal to 1Mpa (i.e., its internal gas pressure is 1Mpa or higher), and the helium 4 proportional counter tube 04 is used as a neutron detector and is used to generate ionized particles;

[0042] A neutron moderation collimator 03 encapsulates the helium-4 proportional counter tube 04. The neutron moderation collimator 03 is made of a common neutron moderation material such as polyethylene, and has a thickness greater than or equal to 5 cm. The neutron moderation collimator 03 is used to scatter and moderate the neutrons generated by the nuclear fusion device 01 outside its line of sight to achieve a collimation effect. The nuclear fusion device 01 generates a neutron distribution area 02;

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

[0044] A pulse height analyzer 06, for receiving the amplified output signal and outputting a 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 the deuterium-tritium neutron response energy spectrum, 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 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 tube contains a trace amount of helium-3, and the reaction energy of helium-3 and thermal neutrons is used to calibrate the system energy. 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, wherein f is a predetermined detection efficiency ratio and k is a ratio of the fraction of deuterium-deuterium neutrons to the fraction of deuterium-tritium neutrons in the output of the pulse height analyzer 06 .

[0049] As a further implementation, the pulse height spectrum is fitted based on a predetermined deuterium-deuterium neutron response energy spectrum and a deuterium-tritium neutron response energy spectrum using a least square method.

[0050] As a further implementation, the neutron measurement device further 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 a bias voltage to the helium 4 proportional counter tube 04 to collect ionized particles generated in the helium 4 proportional counter tube 04;

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

[0053] In specific implementation, the neutron moderator collimator 03 is a horizontally placed cylinder with a through hole dug on the axis of the cylinder, and 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, the neutrons generated by the nuclear fusion device 01 are distributed in the neutron distribution area 02, and the neutron moderation collimator 03 is used to scatter and moderate the neutrons generated by the nuclear fusion device 01 outside its line of sight; secondly, the helium-4 proportional counter tube 04 is used as a neutron detector to detect the above neutrons and generate ionized particles; then, the output signal of the helium-4 proportional counter tube 04 is amplified by the amplifier 05; and 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, so as to obtain the ratio of the deuterium-deuterium neutron fraction to the deuterium-tritium neutron fraction in the output of the pulse height analyzer 06, and calculate the ratio of the deuterium-deuterium neutrons to the deuterium-tritium neutrons generated by the nuclear fusion device 01.

[0054] The invention can measure the time evolution of deuterium-tritium neutrons in a deuterium-deuterium fusion environment, and because the device is not dependent on a photomultiplier tube, it is not susceptible to interference.

[0055] The neutron measuring device of the present invention is suitable for measuring the ratio of deuterium-deuterium fusion neutrons or deuterium-tritium fusion neutrons in a fusion device, and is particularly suitable for detecting the generation of deuterium-tritium fusion neutrons in a fusion device; the present invention is suitable for measuring the time evolution of deuterium-deuterium neutrons and the time evolution of deuterium-tritium neutrons. In particular, a plurality of the neutron measuring devices form an array, which is suitable for measuring the spatial distribution of deuterium-deuterium fusion neutrons in a nuclear fusion device and the spatial distribution of deuterium-tritium fusion neutrons.

[0056] Example 2

[0057] The difference between this embodiment and embodiment 1 is that this embodiment further provides a process for determining a predetermined detection efficiency ratio, and the process for determining the predetermined detection efficiency ratio is:

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

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

[0060] According to the first detection efficiency f1 and the second detection efficiency f2, a detection efficiency ratio f=f1 / f2 is determined.

[0061] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0062] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0063] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0064] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0065] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method 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 in the scope of protection of the present invention.

Claims

1. A neutron measuring device for a helium-4 proportional counter tube, characterized in that: The neutron measurement device comprises: Helium 4 proportional counter tube (04), a proportional counter tube with helium 4 as main gas, with internal gas pressure greater than or equal to 1 MPa, used as a neutron detector and for generating ionized particles; The neutron moderation collimator (03) encloses the helium-4 proportional counter tube (04) and is used to scatter and moderate the neutrons generated by the nuclear fusion device (01) outside its line of sight to achieve collimation; An amplifier (05) for amplifying the output signal of the helium-4 proportional counter tube (04); A pulse height analyzer (06), used for receiving the amplified output signal and outputting a pulse height spectrum; A calculation module (07) is used to receive the pulse height spectrum, and fit the pulse height spectrum based on a predetermined deuterium-deuterium neutron response energy spectrum and a deuterium-tritium neutron response energy spectrum, obtain the ratio of the fraction of deuterium-deuterium neutrons to the fraction 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 of the helium-4 proportional counter tube according to claim 1, characterized in that: The main gas also includes heavy inert gas.

3. The neutron measuring device of the 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 of the 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 of the 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, wherein f is a predetermined detection efficiency ratio and k is a ratio of the fraction of deuterium-deuterium neutrons to the fraction of deuterium-tritium neutrons in the output of the pulse height analyzer (06).

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

7. The neutron measuring device of the 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 high-voltage direct current power supply (09) is used to provide a bias voltage to the helium-4 proportional counter tube (04) so ​​as to collect ionized particles generated in the helium-4 proportional counter tube (04); The DC low-voltage power supply (08) is used to supply power to the amplifier (05).

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

9. The neutron measuring device of the helium-4 proportional counter tube according to claim 1, characterized in that: The neutron measuring device is adapted to measure the time evolution of deuterium-deuterium neutrons and the time evolution of deuterium-tritium neutrons.

10. The neutron measuring device of the helium-4 proportional counter tube according to claim 1, characterized in that: A plurality of the neutron measuring devices form an array, which is suitable for measuring the spatial distribution of deuterium-deuterium fusion neutrons and the spatial distribution of deuterium-tritium fusion neutrons in a nuclear fusion device.

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