A new method for calibrating gamma detectors in the 5-20 MeV energy range
High-energy gamma rays are generated by (p, γ) resonance nuclear reaction. By bombarding the target material with a proton accelerator to calibrate the gamma detector, high-precision energy and efficiency calibration in the 5-20 MeV energy range is achieved, solving the problem of inaccurate calibration in existing technologies.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-29
- Publication Date
- 2026-03-13
AI Technical Summary
Existing technologies are insufficient for accurately calibrating gamma detectors for 5-20 MeV high-energy gamma rays, and the reliance on low-energy radiation sources combined with Monte Carlo simulation methods is not precise enough.
High-energy gamma rays are generated by (p, γ) resonance nuclear reaction. These gamma rays are then produced by bombarding target materials such as 19F, 13C, 27Al, 7Li, and 3H with a proton accelerator to generate monoenergetic gamma rays. The energy and efficiency of the detector are calculated based on experimental data.
It provides a more accurate calibration method, obtains more reliable efficiency data, and solves the problem of insufficient accuracy of traditional methods.
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Figure CN115826032B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of gamma ray efficiency calibration technology, specifically relating to a new method for calibrating a gamma detector in the 5-20MeV energy range. Background Technology
[0002] Quasi-monoenergetic gamma rays of 5-20 MeV have important application prospects in the measurement and research of key nuclear reaction sections in nuclear astrophysics, radiation effect research, nuclear medicine imaging technology research, container inspection technology research, and nuclear waste transmutation technology research.
[0003] Currently, generating quasi-monoenergetic high-energy gamma rays via laser Compton backscattering is considered the most ideal method for producing such rays. To accurately measure the yield and energy of quasi-monoenergetic high-energy gamma rays generated by a laser Compton backscattering gamma source, precise calibration of the energy and efficiency of the detector system is required. However, since natural radioactive sources can only produce monoenergetic gamma rays up to approximately 3.5 MeV, the energy and efficiency calibration of gamma detectors for high-energy gamma rays in the 5-20 MeV energy range is currently mainly determined by combining radioactive source calibration with Monte Carlo simulations. Summary of the Invention
[0004] The purpose of this invention is to provide a new method for calibrating gamma detectors in the 5-20 MeV energy range. This method can calibrate the detector based on a high-energy gamma source generated by (p, γ) resonance nuclear reaction, providing experimental data for the energy and efficiency calibration of high-energy detectors in the 5-20 MeV range. This method enables the calibration of the energy and efficiency of gamma detectors.
[0005] To achieve the above objectives, the technical solution adopted by this invention is: a new method for calibrating a gamma detector in the 5-20 MeV energy range, comprising the following steps:
[0006] S1. A proton beam accelerated by a proton accelerator bombards the target material, causing a resonant nuclear reaction and producing monoenergetic high-energy gamma rays.
[0007] Wherein, the resonant nuclear reaction is a (p, γ) resonant nuclear reaction;
[0008] S2. Determine the corresponding gamma ray flux incident on the detector to be calibrated based on the yield of single-energy high-energy gamma rays generated when different target materials undergo different nuclear resonance reactions.
[0009] S3. Calculate the detection efficiency of the detector to be calibrated in the 5-20MeV high-energy gamma-ray region.
[0010] Furthermore, the target material includes 19 F, 13 C27 Al、 7 Li, 3 H.
[0011] Furthermore, step S1 includes the following specific steps:
[0012] S11. Select a proton beam with appropriate energy to bombard different target materials to induce different resonant nuclear reactions;
[0013] S12, different resonance nuclear reactions produce corresponding monoenergetic high-energy gamma rays.
[0014] Furthermore, the aforementioned 19 F, 13 C 27 Al、 7 Li, 3 H occurs respectively 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 H(p,γ) resonance nuclear reaction.
[0015] Furthermore, the aforementioned 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 During the H(p,γ) resonance nuclear reaction, monoenergetic high-energy gamma rays with energies of 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV are produced.
[0016] Furthermore, step S2 includes the following specific steps:
[0017] according to 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 The yields of single-energy high-energy gamma rays (6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV) produced by the H(p,γ) resonance nuclear reaction can be determined by combining the corresponding incident proton numbers. The gamma ray flux of these single-energy high-energy gamma rays incident on the detector to be calibrated can be determined.
[0018] Furthermore, step S3 includes the following specific steps:
[0019] S31. Read out the energy spectrum of gamma rays from different target materials that undergo resonant nuclear reactions, as measured by the detector to be calibrated.
[0020] S32. Calculate the detection efficiency of the detector to be calibrated for different monoenergetic high-energy gamma rays, and obtain the efficiency scale of the detector to be calibrated in the high-energy gamma ray region.
[0021] Furthermore, step S31 includes the following specific steps:
[0022] Based on the different target materials measured by the calibrated detector 19 F, 13 C 27 Al、 7 Li, 3 H occurs respectively 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 The energy spectrum of gamma rays from the H(p,γ) resonance nuclear reaction was read out, and the gamma ray flux corresponding to the monoenergetic gamma rays of 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV measured by the detector to be calibrated was obtained.
[0023] Furthermore, step S32 includes the following specific steps:
[0024] The gamma-ray flux corresponding to the 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV monoenergetic gamma rays measured by the detector to be calibrated in step S31 is combined with the gamma-ray flux of the corresponding 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV monoenergetic gamma rays incident on the detector to be calibrated in step S2. The detection efficiency of the detector to be calibrated for 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV monoenergetic high-energy gamma rays is calculated, and the energy and efficiency calibration of the detector for 5-20 MeV high-energy gamma rays is obtained.
[0025] The beneficial effects of this invention are as follows: The method for calibrating a gamma detector in the 5-20 MeV energy range provided by this invention involves the following steps: bombarding a target material with a proton beam accelerated by a proton accelerator to induce a (p, γ) resonance nuclear reaction and generate monoenergetic high-energy gamma rays; determining the corresponding gamma ray flux incident on the detector to be calibrated based on the yield of monoenergetic high-energy gamma rays generated when different target materials undergo different nuclear resonance reactions; calculating the detection efficiency of the gamma detector to be calibrated in the 5-20 MeV high-energy gamma ray range. This method, based on a high-energy gamma source generated by a (p, γ) resonance nuclear reaction, allows for calibration of the detector's energy and efficiency. Compared with the traditional extrapolation method using a low-energy radioactive source combined with Monte Carlo simulation, the method for obtaining efficiency calibration based on experimental data provided by this invention has higher accuracy and more reliable efficiency data. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of a new method for calibrating a gamma detector in the 5-20MeV energy range according to an embodiment of the present invention.
[0027] Figure 2 This is a schematic diagram of a system for implementing a method for calibrating a gamma detector in the 5-20 MeV energy range, provided by an embodiment of the present invention. Detailed Implementation
[0028] The technical solutions in the embodiments of the present invention will be further described clearly and completely below with reference to the accompanying drawings and examples. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0029] It should be noted that in the description of the embodiments of the present invention, the terms "upper," "lower," "front," "rear," "front face," "back face," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0030] Given the lack of experimental data and the limited methods for calibrating high-energy detectors in the 5-20 MeV range, the inventors proposed using high-energy gamma rays generated by (p, γ) resonant nuclear reactions as the light source for calibrating detectors. This would provide experimental data for the energy and efficiency calibration of 5-20 MeV high-energy detectors, and the calibration results would be more accurate. Currently, there are no reports internationally on using the aforementioned (p, γ) resonant nuclear reactions for gamma detector calibration.
[0031] Guided by the above-mentioned inventive concept, the purpose of this embodiment is to propose a method for calibrating a detector using a high-energy gamma source generated by a (p, γ) resonance nuclear reaction, and to utilize a proton accelerator to accelerate proton bombardment of target materials. 13 C can be used to generate high-energy gamma rays with a monoenergetic energy of 9.17 MeV, which can be used to bombard target materials. 27 Al can generate high-energy gamma rays with a single energy of 10.7 MeV, and bombarding natural LiF target materials can generate high-energy gamma rays with single energies of 6.13 MeV and 17.6 MeV, respectively, enabling the calibration of the energy and efficiency of gamma detectors. Compared to the traditional method of using low-energy radiation sources combined with Monte Carlo simulations, the calibration method based on experimental data provided in this embodiment is more accurate and yields more reliable efficiency data than the extrapolation method based on Monte Carlo simulations.
[0032] like Figure 1 , Figure 2 As shown, this invention provides a novel method for calibrating a gamma detector in the 5-20 MeV energy range, the method comprising the following steps:
[0033] S1. A proton beam accelerated by a proton accelerator is used to bombard a prepared target material to induce a resonant nuclear reaction and generate monoenergetic high-energy gamma rays; wherein the resonant nuclear reaction is a (p, γ) resonant nuclear reaction.
[0034] Optionally, the target material includes 19 F, 13 C 27 Al、 7 Li, 3 H, etc.
[0035] Specifically, step S1 includes the following steps:
[0036] S11. Select a proton beam with appropriate energy to bombard different target materials to induce different resonant nuclear reactions;
[0037] For different target materials, it is necessary to bombard them with proton beams of appropriate energy to induce different resonant nuclear reactions.
[0038] Specifically, different target materials undergo different resonant nuclear reactions: 19 F, 13 C 27 Al、 7 Li, 3 H occurs respectively 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 H(p,γ) resonance nuclear reaction.
[0039] In one specific embodiment, a proton beam with a proton energy of 340 keV is selected to bombard the target material. 19 F, occurs 19 F(p,αγ) resonance nuclear reaction; a proton beam with a proton energy of 1.75 MeV was selected to bombard the target material. 13 C, occurred 13 C(p,γ) resonance nuclear reaction; proton beam bombardment of target material with proton energy of 1 MeV was selected. 27 Al, occurred 27 Al(p,γ) resonance nuclear reaction; a proton beam with a proton energy of 440 keV was selected to bombard the target material. 7 Li, occurred 7 Li(p,γ) resonance nuclear reaction; proton beam bombardment of target material with proton energy of 1 MeV was selected. 3 H, occurs 3 H(p,γ) resonance nuclear reaction.
[0040] S12, different resonance nuclear reactions produce corresponding monoenergetic high-energy gamma rays.
[0041] In one specific embodiment, the target material 19 F, 13 C 27 Al、 7 Li, 3 H occurs respectively 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 The H(p,γ) resonance nuclear reaction produces high-energy gamma rays with monoenergetic energies of 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV, respectively.
[0042] S2. Determine the corresponding gamma ray flux incident on the detector to be calibrated based on the yield of single-energy high-energy gamma rays generated when different target materials undergo different nuclear resonance reactions.
[0043] Before bombarding the prepared target material with a proton beam accelerated by a proton accelerator, the calibration detector is placed directly in front of the target material along the direction of the proton beam to receive the monoenergetic high-energy gamma rays. The proton beam enters the first side of the target material, and the calibration detector is located on the opposite side of the first side of the target material.
[0044] Step S2 includes the following specific steps: According to 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 The yields of single-energy high-energy gamma rays (6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV) produced by the H(p,γ) resonance nuclear reaction can be determined by combining the corresponding incident proton numbers. The gamma ray flux of these single-energy high-energy gamma rays incident on the detector to be calibrated can be determined.
[0045] In one specific embodiment 7 The yield of 17.6 MeV monoenergetic high-energy gamma rays produced by the Li(p,γ) resonance nuclear reaction is (3.2 ± 0.2) × 10⁻⁶. -9 γ / p, according to 7 The yield of 17.6 MeV gamma rays produced by the Li(p,γ) resonance nuclear reaction, combined with the corresponding number of incident protons obtained by the charge collector, is calculated according to the following formula:
[0046] Number of incident protons × gamma ray yield = gamma ray flux incident on the detector to be calibrated
[0047] The gamma-ray flux of a 17.6 MeV monoenergetic high-energy gamma ray incident on the detector to be calibrated can be determined.
[0048] S3. Calculate the detection efficiency of the calibration detector in the 5-20MeV high-energy gamma-ray region.
[0049] Specifically, step S3 includes the following steps:
[0050] S31. Read out the energy spectrum of gamma rays from different target materials that undergo resonant nuclear reactions, as measured by the detector to be calibrated.
[0051] Specifically, based on the different target materials measured by the detector to be calibrated 19 F, 13 C 27 Al、 7 Li, 3 H occurs respectively 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 The energy spectrum of gamma rays from the H(p,γ) resonance nuclear reaction can be used to read the gamma ray flux corresponding to the monoenergetic gamma rays of 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV measured by the detector to be calibrated.
[0052] S32. Calculate the detection efficiency of the detector to be calibrated for different single-energy high-energy gamma rays, and obtain the efficiency scale of the detector to be calibrated in the high-energy gamma ray region.
[0053] Specifically, the gamma-ray flux corresponding to the 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV monoenergetic gamma rays measured by the detector to be calibrated in step S31 is divided by the gamma-ray flux of the 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV monoenergetic high-energy gamma rays incident on the detector to be calibrated, as determined in step S2. The detection efficiency of the detector to be calibrated for the 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, and 19.8 MeV monoenergetic high-energy gamma rays can be calculated, and the energy and efficiency calibration of the detector to be calibrated in the 5-20 MeV high-energy gamma-ray region can be obtained.
[0054] Compared with the traditional extrapolation method using low-energy radioactive sources combined with Monte Carlo simulations, the method for obtaining efficiency scales based on experimental data provided in this embodiment is more accurate and the obtained efficiency data is more reliable.
[0055] The methods described in this invention are not limited to the specific embodiments described above. The embodiments are merely illustrative examples of this invention, and this invention can also be implemented in other specific ways or forms without departing from the spirit or essential characteristics of this invention. Therefore, the described embodiments should be considered illustrative rather than limiting in any respect. The scope of this invention should be defined by the appended claims, and any variations equivalent to the intent and scope of the claims should also be included within the scope of this invention.
Claims
1. A new method of calibration of a gamma detector in the energy region 5-20 MeV, characterized in that, It comprises the following steps: S1, using proton beam accelerated by proton accelerator to bombard target material, resonance nuclear reaction occurs, and single-energy high-energy gamma rays are generated; wherein, the resonance nuclear reaction is (p, γ) resonance nuclear reaction; The target material includes 19 F, 13 C, 27 Al, 7 Li, 3 H, the 19 F, 13 C, 27 Al, 7 Li, 3 H respectively occur 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 H(p,γ) resonance nuclear reaction; The step S1 comprises the following specific steps: S11, selecting a proton beam with appropriate energy to bombard different target materials to respectively occur different resonance nuclear reactions; S12, different resonance nuclear reactions respectively produce corresponding single-energy high-energy gamma rays; S2, according to the yield of single-energy high-energy gamma rays produced by different nuclear resonance reactions of different target materials, determine the corresponding gamma ray flux incident into the to-be-calibrated detector; S3, calculate the detection efficiency of the to-be-calibrated detector in the 5-20MeV high-energy gamma ray region.
2. A new method of calibration of a gamma detector in the energy region 5-20 MeV according to claim 1, characterized in that, occurrence 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 H(p,γ) resonance nuclear reaction, corresponding to the production of energy of 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, 19.8 MeV mono-energy high-energy gamma rays.
3. A new method of calibration of a gamma detector in the energy region 5-20 MeV according to claim 2, characterized in that, The step S2 comprises the following specific steps: According to 19 F(p,αγ), 13 C(p,γ), 27 Al(p,γ), 7 Li(p,γ), 3 H(p,γ) resonance nuclear reaction respectively produce 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, 19.8 MeV single-energy high-energy gamma ray yield corresponding to the yield, combined with the corresponding incident proton number, can determine the 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, 19.8 MeV single-energy high-energy gamma ray respectively incident to the gamma ray flux of the detector to be calibrated.
4. A new method of calibration of a gamma detector in the energy region 5-20 MeV according to claim 3, characterized in that, The step S3 comprises the following specific steps: S31, read out the gamma ray energy spectrum of the resonance nuclear reaction of the different target materials measured by the to-be-calibrated detector; S32, calculate the detection efficiency of the to-be-calibrated detector for different single-energy high-energy gamma rays, and obtain the efficiency calibration of the to-be-calibrated detector in the high-energy gamma ray region.
5. A new method of calibration of a gamma detector in the energy region 5-20 MeV according to claim 4, characterized in that, The step S31 comprises the following specific steps: According to the different target materials measured by the detector to be calibrated 19 F、 13 C、 27 Al、 7 Li、 3 H respectively occur 19 F(p,αγ)、 13 C(p,γ)、 27 Al(p,γ)、 7 Li(p,γ)、 3 H(p,γ) resonance nuclear reaction gamma-ray spectrum, respectively read out the 6.13 MeV, 9.17 MeV, 10.78 MeV, 17.6 MeV, 19.8 MeV single-energy gamma-ray corresponding to the gamma-ray flux measured by the detector to be calibrated.
6. A new method of calibration of a gamma detector in the energy region 5-20 MeV according to claim 5, characterized in that, The step S32 comprises the following specific steps: The gamma ray flux corresponding to the 6.13MeV, 9.17MeV, 10.78MeV, 17.6MeV, 19.8MeV single-energy gamma rays measured by the to-be-calibrated detector in step S31 is combined with the corresponding 6.13MeV, 9.17MeV, 10.78MeV, 17.6MeV, 19.8MeV single-energy gamma rays incident into the to-be-calibrated detector determined in step S2, the detection efficiency of the to-be-calibrated detector for 6.13MeV, 9.17MeV, 10.78MeV, 17.6MeV, 19.8MeV single-energy high-energy gamma rays is calculated, and the 5-20MeV high-energy gamma ray is obtained. Energy and efficiency calibration of the gamma detector.