Neutron beam detecting device, neutron beam detecting method, and neutron beam detecting program

Abstract

The neutron beam detection device of the present application is provided with: a first solar cell type detector, which has a conversion film attached to its surface that converts neutrons into any one of a charged particle beam of a photon, an alpha particle, a proton, a lithium nucleus, a gamma ray, and a beta ray, and generates a current by incident radiation; a radiation detector that generates a current having no sensitivity to neutrons as an output signal due to radiation incident; a current measurer that detects the current generated by the first solar cell type detector and the current generated by the radiation detector due to radiation incident as signals; and a flux calculation section that compares the current signals from the detector detected by the current measurer. The flux calculation section corresponds the detected current signals from the solar cell type detector and the radiation detector to a relationship between the flux of a prescribed kind of incident radiation and the detected current from the solar cell type detector and the radiation detector, which is obtained in advance, and calculates the flux of the neutron beam.

Description

Technical Field

[0001] This invention relates to a neutron beam detection device, a neutron beam detection method, and a neutron beam detection procedure. Background Technology

[0002] As a technique for detecting neutron beams, there are known methods that utilize neutrons and alpha particles generated by a gas or solid containing boron or other substances that produce alpha particles through neutrons to ionize the enclosed gas molecules, collect the generated charge onto an electrode with a high voltage applied, and then detect it.

[0003] In addition, there are known methods that amplify light signals from a substance called a scintillator, which emits light through the energy of alpha particles, into electrical signals using photomultiplier tubes or similar devices, thereby detecting neutron beams. Currently, these two detection methods are widely known as representative and common methods for neutron beam detection.

[0004] In addition, regarding neutron detectors using semiconductors, the technologies described in Patent Document 1 and Patent Document 2 are known.

[0005] In the detector of the technology described in Patent Document 1, an intrinsic semiconductor layer containing boron that converts neutrons into alpha rays is inserted at the middle of the p / n junction of the diode structure.

[0006] In the detector of the technology described in Patent Document 2, an organic conversion layer made of organic matter is used as the semiconductor material, but no element that converts neutrons into alpha rays is used. In addition, a voltage needs to be applied to operate the detector.

[0007] Patent Document 3 discloses a sensor for measuring different types of radiation, in which electrodes with diode pin junctions or Schottky junctions are fabricated, and a membrane for detecting X-rays and gamma rays, alpha rays and beta rays, neutron beams, etc., is fabricated on the surface of the electrode. This sensor measures the amount of flashes generated by X-rays and gamma rays, the transmittance of alpha rays and beta rays, and the amount of chemical reactions occurring through neutron-reacting substances.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 2018-141749

[0011] Patent Document 2: Japanese Patent Application Publication No. 2019-145751

[0012] Patent Document 3: Japanese Patent Publication No. 2016-539324 Summary of the Invention

[0013] To obtain sufficient detection sensitivity, a certain amount of gas volume is required for neutron detectors using the aforementioned gas ionization, which inevitably leads to an increase in the size of the detection unit.

[0014] In addition, boron trifluoride is required. 3 Using expensive gases such as He as encapsulation gases also requires a power source to apply voltage, resulting in high detector costs.

[0015] Regarding the testing equipment in Patent Document 1 and Patent Document 2, it is necessary to design and manufacture specialized testing equipment with special structures. If the costs involved in establishing the stability and reliability of product performance are also included, the price of the detector will increase.

[0016] In the sensor for measuring different types of radiation described in Patent Document 3, the radiation passing through each membrane is a tiny analog signal, which is not easy to convert. Considering noise interference, the sensor's practicality is considered low. In addition, since it is necessary to measure the pulse signal amplified by a preamplifier using an external power supply, there is a problem with signal detection.

[0017] The present invention was made in view of the above-mentioned problems of the prior art, and its object is to provide a neutron detection device that can easily detect neutrons with a small detector.

[0018] Furthermore, the present invention aims to provide a neutron beam detection method and a neutron beam detection procedure using the aforementioned neutron beam detection device.

[0019] As a means of solving the above-mentioned problems, the present invention has the following structure.

[0020] (1) The neutron detection apparatus according to this embodiment is a neutron beam detection apparatus for detecting neutron beams, comprising: a solar cell detector having a conversion film attached to its surface that converts neutrons into a predetermined type of radiation, and generating a current by incident radiation through the conversion film; a radiation detector that generates a current insensitive to neutrons as an output signal due to the incident radiation; a current measuring device that detects the current generated by the solar cell detector and the current generated by the radiation detector due to the incident radiation as signals; and a flux calculation unit that compares the current signal generated by the solar cell detector and the current signal generated by the radiation detector detected by the current measuring device. The flux calculation unit has a function that is, to calculate the flux of the neutron beam based on the relationship between the current signals detected by the current measuring device from the solar cell detector and the radiation detector corresponding to the flux of a predetermined type of incident radiation and the detection current from the solar cell detector and the radiation detector.

[0021] The solar cell detectors described here are preferably PN junction devices, which are pre-designed to increase the current output caused by light irradiation, enabling the output of the detection signal obtained through internal potential drive, and thus improving radiation resistance. In the case of this device, it differs significantly from photodiode detectors designed to require an external voltage or signal amplification via a preamplifier in terms of functionality, the need for an external power supply, and radiation resistance.

[0022] According to this embodiment, the neutron detection device can use solar cells manufactured using existing technology, eliminating the need to design and manufacture dedicated detection equipment with special structures. Furthermore, the internal electric field of the p / n junction diode structure is used to extract the charge generated by absorbing any of the charged particle beams, including photons, alpha particles, protons, lithium nuclei, gamma rays, and beta rays, thus eliminating the need for an applied voltage. Therefore, no voltage source or circuitry or wiring for applying voltage is required, and a simple structure can serve as a neutron detection system, enabling cost reduction.

[0023] Furthermore, using a detector approximately 1 cm square as a solar cell-type detector is sufficient to achieve the structure of this embodiment, thus reducing the size of the neutron detection section. As a result, it becomes possible to measure neutron beams in locations that are currently difficult to install or impossible to measure, such as near the neutron generation section of an accelerator-type neutron generation device.

[0024] (2) In the neutron detection device involved in the present invention, preferably, the solar cell detector is a first solar cell detector and the radiation detector is a second solar cell detector, which does not have a conversion membrane to convert neutrons into a specified radiation. The flux calculation unit calculates the difference between the current signal from the first solar cell detector and the current signal from the second solar cell detector. It has the function of corresponding this difference to the relationship between the flux of a predetermined type of incident neutron and the difference between the detection current from the first solar cell detector, and calculating the flux of the neutron beam based on the corresponding result.

[0025] (3) In the neutron detection device involved in the present invention, preferably, the neutron beam detection device has the function of calculating neutron flux based on a calibration curve based on a linear function, a power function, or a quadratic function that is pre-stored in the flux calculation unit.

[0026] (4) In the neutron detection device of the present invention, preferably, the conversion membrane is composed of any one of the following: a single element of lithium, boron or gadolinium, wherein lithium, boron or gadolinium contains an isotope that has the function of converting neutrons into a beam of any charged particle among photons or alpha particles, protons, lithium nuclei, gamma rays and beta rays; or a nitride, fluoride, oxide or other compound of lithium, boron or gadolinium, wherein lithium, boron or gadolinium contains an isotope that has the function of converting neutrons into a beam of any charged particle among photons or alpha particles, protons, lithium nuclei, gamma rays and beta rays; or a mixture of the single element and the compound.

[0027] (5) In the neutron detection device involved in the present invention, preferably, the solar cell detector is composed of any one of the following: a binary compound semiconductor with a band gap of 0.8eV to 2.2eV, such as gallium arsenide, indium phosphide, cadmium telluride, etc.; or a compound semiconductor, which is a ternary or quaternary or more multi-element mixture, such as indium gallium phosphide, gallium aluminum arsenide, copper indium selenide, etc.; or a perovskite semiconductor.

[0028] (6) The neutron detection method of the present invention is a neutron beam detection method for detecting neutron beams, comprising: using a solar cell detector and a radiation detector, wherein the solar cell detector has a conversion film attached to its surface to convert neutrons into a specified radiation, a current is generated by incident radiation through the conversion film, and the radiation detector generates a current that is insensitive to neutrons as an output signal due to the incident radiation; a current measuring device detects the current generated by the solar cell detector due to the incident radiation and the current generated by the radiation detector as signals; a flux calculation unit compares the current signal generated by the solar cell detector and the current signal generated by the radiation detector detected by the current measuring device with the current signal generated by the radiation detector; and the flux calculation unit calculates the flux of the neutron beam based on the relationship between the current signal detected by the current measuring device from the solar cell detector and the radiation detector and the flux of a predetermined type of incident radiation, and the detection current from the solar cell detector and the radiation detector.

[0029] The neutron beam detection program involved in this invention is a program used in a neutron beam detection method for detecting neutron beams. It is run to perform the following operations: using a solar cell detector and a radiation detector, wherein the solar cell detector is equipped with a conversion membrane that converts neutrons into a specified type of radiation; generating a current by incident radiation through the conversion membrane; and the radiation detector generating a current insensitive to neutrons as an output signal due to the incident radiation. A current meter detects the current generated by the solar cell detector and the current generated by the radiation detector due to the incident radiation. A flux calculation unit compares the current signal generated by the solar cell detector and the current signal generated by the radiation detector, detected by the current meter. The flux calculation unit then correlates the current signals detected by the current meter from the solar cell detector and the radiation detector with the flux of a predetermined type of incident radiation and the detection current from the solar cell detector and the radiation detector, and calculates the neutron beam flux based on the corresponding results.

[0030] According to the present invention, a neutron beam detection device can be provided that can measure and calculate the flux of a neutron beam with a wider detection range, lower price, wider operating temperature range, and smaller detection device configuration volume.

[0031] Furthermore, according to the present invention, a neutron beam detection method and a neutron beam detection procedure can be provided, which can measure and calculate the flux of a neutron beam with a wider detection range, lower price, wider operating temperature range, and smaller detection device configuration volume. Attached Figure Description

[0032] Figure 1 This is a system block diagram illustrating the neutron beam detection apparatus according to the first embodiment of the present invention.

[0033] Figure 2 This is a diagram showing the cross-sectional structure of the InGaP solar cell-type detector applied to the neutron beam detection apparatus of the first embodiment.

[0034] Figure 3 This is a graph showing the relationship between the total amount of alpha particles produced at the side surface of a boron plate solar cell, calculated by way of calculation, and the incident amount of neutrons with an energy of 50 meV.

[0035] Figure 4 This is a graph showing the relationship between the flux of alpha particles with an energy of 200 keV (the flux of He ion irradiation) and the output current (induced current) of an InGaP solar cell.

[0036] Figure 5 This is a graph showing the generation current (induced current) from each solar cell when neutrons are irradiated onto solar cells with and without conversion films using a neutron generating device equipped with an accelerator.

[0037] Figure 6 This is a graph representing the ratio of the current generated by an InGaP solar cell to the energy of the alpha particle (normalized to 1 for a 200keV alpha particle).

[0038] Figure 7 This is a graph showing the relationship between the energy of the alpha particle generated and emitted by a neutron incident in a conversion film (a boron film with a thickness of 0.05 mm), calculated by Monte Carlo simulation, and the number of alpha particles generated at the surface of the solar cell of the boron film. It is used to illustrate that the spectrum is independent of the energy of the incident neutron and is the same for neutrons of any energy.

[0039] Figure 8 It is a graph showing the relationship between the energy and the number of neutrons produced by the neutron generating device used in the embodiment (normalized to a peak energy value of 1).

[0040] Figure 9This is a graph showing the relationship between neutron energy and a physical quantity called the reaction cross section, which has the meaning of... 10 The probability that B absorbs an incident neutron and produces an alpha particle.

[0041] Figure 10 It is a graph showing the measurement results of the current density generated when a 650nm monochromatic light source is irradiated onto a solar cell detector while the light intensity is changed.

[0042] Figure 11 This is a graph showing the difference in neutron-related sensitivity for conversion films containing boron carbide (B4C) and those containing lithium fluoride (LiF).

[0043] Figure 12 This is a graph showing the dependence of the amount of alpha particles emitted from the incident and transmitted sides of the neutrons on the membrane thickness when 25 meV neutrons are incident on a boron-containing conversion membrane.

[0044] Figure 13 It means possessing Figure 1 The diagram shows one configuration of the neutron beam measurement system S of the neutron beam detection device A.

[0045] Figure 14 This is a configuration diagram showing an example of a computer (processing unit) that stores a program for the neutron detection apparatus according to the first embodiment.

[0046] Figure 15 This is a graph illustrating the calibration curves, which show the results for each region. Figure 10 The data shown represents the relationship between current density and neutron flux when the data is fitted with a linear, power, or quadratic function. Detailed Implementation

[0047] [First Implementation Method]

[0048] The present invention will now be described in detail by way of examples of the first embodiments of the invention. However, the present invention is not limited to the embodiments described below.

[0049] Figure 1 This is a system block diagram illustrating the neutron beam detection apparatus according to the first embodiment of the present invention. The neutron beam detection apparatus A of this embodiment includes a first solar cell type detector 1 having a conversion membrane 6 (described later), a radiation detector (second solar cell type detector) 2 without the conversion membrane 6, current measuring devices 3 and 4, and a neutron beam flux calculation device 5.

[0050] The first solar cell type detector 1 is a detector that generates an electric current when irradiated by radiation such as sunlight. A conversion film 6 is laminated on the radiation input section (light-receiving surface) of this first solar cell type detector 1, which has the function of generating a beam of any charged particle among photons, alpha particles, protons, lithium nuclei, gamma rays, and beta rays when irradiated by neutrons. This conversion film 6 can be described as a conversion film that converts a neutron beam into the aforementioned radiation.

[0051] Figure 2 The main structural components of a first solar cell-type detector 1 with a conversion film 6 are shown.

[0052] The first solar cell detector 1 has a diode structure of the p / n junction type of solar cell formed by bonding a p-type semiconductor layer and an n-type semiconductor layer. For example, it has the following structure: an electrode layer 10 is laminated on the back side of a laminate 9 formed by laminating a p-type layer 7 (which is an InGaP layer) and an n-type layer 8 (which is an InGaP layer), and an electrode layer 11 is laminated on its front side.

[0053] In the first solar cell detector 1, the electrode layer 11 side is the front side, and the electrode layer 10 and the electrode layer 11 are connected by wiring to form a circuit. When the front side is irradiated by sunlight or other radiation, it generates electricity and allows current to flow through the circuit.

[0054] In the first solar cell detector 1 of this embodiment, a conversion film 6 is laminated on the front side of the electrode layer 11, and the first solar cell detector 1 is equipped with the conversion film 6.

[0055] The radiation detector (second solar cell type detector) 2 of this embodiment has the same structure as the first solar cell type detector 1, except for the conversion film 6. That is, the radiation detector 2 has a diode structure of the p / n junction type solar cell, which is formed by bonding a p-type semiconductor layer and an n-type semiconductor layer. For example, it has the following structure: an electrode layer 10 is laminated on the back side of the laminate 9 formed by laminating a p-type layer 7 (which is an InGaP layer) and an n-type layer 8 (which is an InGaP layer), and an electrode layer 11 is laminated on its front side.

[0056] In the first solar cell detector 1 and the radiation detector (second solar cell detector) 2, the semiconductor composition compound constituting the p-type layer 7 or the n-type layer 8 can be, more specifically, binary compound semiconductors such as gallium arsenide (GaAs), indium phosphide (InP), and cadmium telluride (CdTe); or compound semiconductors that are ternary or quaternary or more multi-component mixtures, such as indium gallium phosphide (InGaP), aluminum gallium arsenide (AlGaAs), copper indium selenide sulfide, etc.; or perovskite semiconductors.

[0057] The conversion film 6 can be, for example, a film composed of any one of the elemental elements lithium (Li), boron (B), and gadolinium (Gd), wherein lithium, boron, and gadolinium contain isotopes that have the function of converting neutrons into charged particle beams or photons when irradiated by neutrons. Alternatively, the conversion film 6 can also be a lithium, boron, or gadolinium nitride film, fluoride film, oxide film, or other compound film. Or, the conversion film 6 may also contain a mixture of any one of the elemental elements lithium, boron, and gadolinium with the lithium compound, boron compound, or gadolinium compound.

[0058] When a neutron is incident on the conversion membrane 6, it reacts with any one of the elements lithium, boron and gadolinium contained in the conversion membrane 6, generating a beam of any charged particle among photons or protons, alpha particles, lithium nuclei, gamma rays and beta rays in all directions starting from the reaction site.

[0059] For example, commonly available industrial lithium has... 6 Li (lithium-6) and 7 The two isotopes Li (lithium-7), 7 The abundance of Li is approximately 93%. 6 The abundance of Li is approximately 7%.

[0060] In addition, commonly used boron available industrially has... 10 B (boron 10) and 11 The two isotopes B (boron-11), 10 The abundance of B is approximately 20%. 11 The abundance of B is approximately 80%.

[0061] In addition, commonly used gadolinium available industrially includes 154 Gd (2.18%) 155 Gd (14%) 156 Gd (20.5%) 157 Gd (15.6%) 158 Gd (24.8%), and 160 The six natural and radioactive isotopes of Gd (21.8%) 152 Gd (0.2%).

[0062] Because these elements contain isotopes (including radioactive isotopes), if neutrons are irradiated into these elements, they will release instantaneously charged particles, such as alpha particles (the nuclei of He atoms), thus converting neutrons into alpha particles.

[0063] When irradiated by neutrons, the conversion membrane 6 converts neutrons into alpha particles, lithium nuclei, and gamma rays. If the thickness of the conversion membrane 6 is excessively increased, some of the alpha particles, lithium nuclei, and gamma rays will attenuate inside the conversion membrane 6. Therefore, even if the conversion membrane 6 is thickened to a necessary extent, some of the alpha particles, lithium nuclei, and gamma rays will still attenuate within the conversion membrane 6. Thus, the thickness of the conversion membrane 6 is preferably around 1 to 10 μm, for example, a very thin membrane of a few μm.

[0064] Conversely, by making the conversion membrane 6 thinner than 1 μm, the detection sensitivity and output current can be reduced. Therefore, the conversion membrane 6 can also be used in high-flux neutron environments. For example, the neutron beam detector 1 with the conversion membrane 6 of this embodiment can be used in high-flux neutron environments such as nuclear reactors or their peripheral equipment. In the case of a high-flux neutron environment, the conversion membrane 6 can, for example, be formed to be about 0.001 to 1 μm.

[0065] In addition, by thinning the conversion film 6 as described above, noise caused by gamma rays can be reduced.

[0066] Current measuring device 3 is electrically connected to the first solar cell detector 1, and current measuring device 4 is electrically connected to the radiation detector (second solar cell detector) 2. Additionally, flux calculation device 5 is electrically connected to current measuring device 3 and current measuring device 4. Current measuring device 3 can measure the induced current generated by the first solar cell detector 1 as a current signal, and current measuring device 4 can measure the induced current generated by the radiation detector 2 as a current signal.

[0067] The flux calculation device 5 includes: a difference calculation unit 15, which compares the current signals measured by the current measuring device 3 and the current measuring device 4 respectively, and calculates the difference between these current signals; and a flux calculation unit 16, which calculates the neutron flux from the current difference based on the calculation result of the difference calculation unit 15, as will be described later.

[0068] In order to calculate the neutron flux by the flux calculation unit 16, the relationships described below must be known in advance and stored in a memory or other storage unit provided in the flux calculation unit 16.

[0069] The first information pre-stored in the flux calculation unit 16 is relational data regarding the degree to which alpha particles are generated in the conversion membrane 6 of the first solar cell detector 1, relative to the flux of incident neutrons. This relational data is obtained by controlling the amount of neutrons generated using an accelerator-type neutron generator or similar device, and by adjusting the accelerator-type neutron generator, thereby obtaining the relationship between the flux of the neutron beam incident on the conversion membrane 6 and the generation rate of alpha particles generated in the conversion membrane 6, for example, as obtained in the embodiments described later. Figure 3 As shown.

[0070] Figure 3 The flux values ​​of incident neutrons with specific energies (e.g., 50 meV) are shown [particles / cm²]. 2 / second (particles per unit area per unit time) and the alpha particle generation rate [particles / cm²] 2 The relationship between [ / second] and [other parameters]. If you understand this... Figure 3 The relationship between these parameters allows us to determine the alpha particle production rate based on the flux of neutrons incident on conversion membrane 6. The alpha particle production rate relates to the extent to which conversion membrane 6 produces alpha particles. Figure 3 The relationships shown must be stored in the throughput calculation unit 16 beforehand.

[0071] The second piece of information pre-stored in the flux calculation device 5 is the relationship between the flux of alpha particle irradiation and the current output of the first solar cell detector 1 when alpha particles are irradiated onto the first solar cell detector 1 without the conversion film 6. This relationship data, for example, is obtained as described in the embodiments described later. Figure 4 As shown in the graph, by setting the horizontal axis to the flux of alpha particle irradiation (He ion irradiation flux: ×10) 9 He + / cm 2 / s), set the vertical axis to the induced current (×10 -5 A) to pre-determine the relationship between the two, Figure 4 The relationships shown are pre-stored in the throughput calculation device 5.

[0072] Next, by changing the current of the incident proton beam using an accelerator-type neutron generator, the flux of neutrons that can be generated from the accelerator-type neutron generator can be controlled. Therefore, the first solar cell-type detector 1 with a conversion membrane 6 and the radiation detector 2 without a conversion membrane 6 are arranged next to each other, and they are irradiated with neutrons generated from the neutron generator.

[0073] If the irradiation test is performed, as determined in the examples described later, Figure 5As shown in the diagram, current outputs from the first solar cell detector 1 (with a conversion film) and current outputs from the radiation detector 2 (without a conversion film) can be obtained.

[0074] from Figure 5 The current value obtained by subtracting the current output of the radiation detector 2 (without a conversion membrane) from the current output of the first solar cell detector 1 shown in the graph can be understood as the current generated by neutrons of the corresponding flux. That is, the difference between the current signals of the current measuring devices 3 and 4 is calculated by the difference calculation unit 15, thereby enabling the calculation of the current generated by the corresponding neutrons.

[0075] In this embodiment, calculating the neutron quantity based on the detected current difference is possible by... Figure 1 The flux calculation unit 16 set in the last level box shown is used for implementation.

[0076] As a calculation method, the following methods can be listed: Pre-calculate the relationship data between the number of corresponding alpha particles and the degree of current induced by the solar cell detector 1 with conversion film 6 (refer to...). Figure 3 Then, based on the relationship data representing the degree to which alpha particles and lithium nuclei are generated from the neutrons absorbed by the corresponding conversion membrane 6 (refer to...), Figure 4 ), to calculate the neutron quantity.

[0077] Alternatively, the following method can be used: For the manufactured solar cell-type detector 1, the induced current is measured in a calibration field where the neutron quantity has been pre-quantified, and the neutron quantity is calculated proportionally based on this value. Figure 4 The results show that the flux and current of neutrons are in a proportional relationship based on a linear or power function.

[0078] Furthermore, the proportional relationships described above are based on observations in the tens of nA range. To obtain a range that guarantees the aforementioned linearity, the characteristics of solar cells can be flexibly utilized to conduct linearity correction experiments using light.

[0079] For example, such as Figure 10 As shown, by measuring the current density generated when a 650nm monochromatic light source is irradiated onto the solar cell detector 2 while changing the light intensity, it is possible to know the behavior of the extremely small number of charge carriers generated in the semiconductor being extracted as current to the external circuit.

[0080] Figure 10The graph shown represents the results obtained by inputting a 635nm wavelength laser (visible light) through a variable attenuator (0 to -60dB) and a two-branch path into a photodiode and a solar cell detector, respectively. The solar cell detector is shown as follows: Figure 2 The structure of the solar cell detector 2 shown is used in the embodiments described later.

[0081] according to Figure 10 The data shown indicates that at a current density of 100 pA / cm², 2 The above (approximately 1×10) -10 A / cm 2 In the region above, high linearity based on linear or power functions persists up to several μA / cm. 2 Therefore, it can be assumed that the induced current caused by radiation also exhibits the same linearity as that of visible light.

[0082] Additionally, at hundreds of pA / cm 2 The following (approximately 1×10) -10 A / cm 2 In the region described below, the linearity is no longer present, and the curve becomes based on a quadratic function. Therefore, by using the induced current behavior caused by the aforementioned visible light as the calibration curve for the solar cell detector 1, it is also possible to analyze the neutron flux in the nonlinear region.

[0083] For example, Figure 15 This represents the data used for calibration curves. Figure 10 When the light intensity value shown is set to 4000 times, it is compared with... Figure 5 The estimated behavior of the induced current induced by neutron irradiation is consistent. The conversion of neutron flux can be calculated by substituting the measured current into the function derived from the calibration curve.

[0084] Figure 15 The region shown for the linear or power function is 100 pA / cm. 2 The region described above, if fitted using a linear function y = dx + e, can be expressed by the relationship y = 7E - 14x + 2E - 09. If fitted using a power function y = x... d If we fit the equation with +e, then we can get y = 6 × 10 16 x 1.002 The relational expression for +0.

[0085] Furthermore, the region of the quadratic function is 1 pA / cm. 2 Up to 100 pA / cm 2 In the region, if the quadratic function y = ax 2 If we fit the equation y = -1E + 27x to bx + c, then we can obtain the equation y = -1E + 27x. 2The relational expression is +1E+17x-170469.

[0086] That is, the calibration curve can be represented using the fitted functional relationship described above. Based on the calibration curves for each of these regions, the relationship between light intensity and the induced current caused by radiation can be determined as neutron flux.

[0087] The solar cell detectors 1 and 2 in this embodiment can be solar cell devices manufactured using existing solar cell manufacturing technology, without requiring special design or manufacturing methods for neutron measurement. This is because current can be directly obtained from the solar cell detectors 1 and 2.

[0088] To achieve sensitivity to neutrons, a conversion film 6, which generates a beam of charged particles or photons upon neutron irradiation, can be directly formed and attached to the surface of the solar cell device using film-forming methods such as coating, vacuum evaporation, or sputtering. Alternatively, the detector can be attached to the solar cell device simply by, for example, attaching a separately fabricated plate-shaped conversion film to the surface of the solar cell device, enabling simple and low-cost fabrication of the detector.

[0089] For example, by replacing the plate-shaped conversion film containing boron carbide (B4C) or lithium fluoride (LiF) on the surface of the solar cell device, it is possible to achieve the following: Figure 11 The sensitivity to neutrons was changed as shown.

[0090] In this case, the conversion membrane is not limited to those containing boron carbide or lithium fluoride. As mentioned earlier, plate or membrane materials containing elements capable of converting neutrons into charged particles or photons are also effective. Since the energy dependence of the neutron absorption cross-section depends on the element, it is possible to easily change the structure of the conversion membrane according to the environment of the neutron to be measured.

[0091] For example, according to Figure 11 The example shown illustrates that a lithium fluoride-containing conversion membrane can be used in environments with high neutron flux, while a boron carbide-containing conversion membrane can be used in environments with low neutron flux.

[0092] The sensitivity / output current of solar cell detectors 1 and 2 is proportional to the area of ​​the solar cell device, thus allowing the sensitivity to be adjusted according to the size of the solar cell device. Using this relationship, the sensitivity can be easily adjusted to match the detection area for the intended application.

[0093] For example, the sensor described in Patent Document 3 has no sensitivity to light, so sensitivity calibration cannot be performed on it. Furthermore, since the pulse signal, amplified from a tiny analog signal by a preamplifier powered by an external power source, is measured, there is a discrepancy; that is, the measurement is not a current signal measurement driven by the internal potential of the solar cell-type detectors 1 and 2.

[0094] Common solar cell devices made from inorganic crystalline materials operate within a temperature range of approximately -150°C to +300°C, thus offering a wider applicable temperature range compared to existing neutron detectors. Utilizing this high-temperature resistance, neutron flux measurements could be performed in or near nuclear reactors at nuclear power plants, operating in such high-temperature environments.

[0095] Furthermore, exposure of the solar cell device to radiation can cause damage during crystallization, potentially leading to a deterioration or reduction in the output current. Therefore, it is necessary to correct for this deterioration when using the neutron beam detection device A of this embodiment continuously. By obtaining data on the reduction in output current of the solar cell device and its exposure to radiation such as alpha particles, beta particles, and gamma rays in advance, and storing this data as a database in the flux calculation unit, self-correction can be performed. If this correction is performed, accurate neutron beam measurement can be achieved even when the solar cell device is used continuously for extended periods in an environment exposed to radiation.

[0096] According to this embodiment, the neutron detection unit can use a solar cell manufactured according to existing technology, eliminating the need to design and manufacture a dedicated detection device with a special structure. Furthermore, the internal electric field of the p / n junction diode structure is used to extract the charge generated by absorbing alpha particles, thus eliminating the need for an applied voltage. Therefore, no voltage source or circuitry or wiring for applying voltage is required, and a neutron detection system can be implemented with a simple structure, enabling low-cost operation.

[0097] Furthermore, using detectors approximately 1 cm square as solar cell-type detectors 1 and 2 is sufficient to realize the structure of this embodiment, thus reducing the size of the neutron detection section. This makes it possible to measure neutron beams in locations that are currently difficult to install or impossible to measure, such as near the neutron generation section of an accelerator-type neutron generator.

[0098] Because solar cell detectors 1 and 2 generate current even when radiation other than neutrons is absorbed, the output of solar cell detector 1, which has a conversion film 6 for neutron / charged particle beams or photons, includes the current generated by radiation other than neutrons. Therefore, the difference must be calculated by detecting radiation other than neutrons using a radiation detector that is insensitive to neutrons. This is also the case for existing neutron detectors.

[0099] However, in the structure of this embodiment, a solar cell detector 2 without a conversion film 6 for neutron / charged particle beams or photons is used as a radiation detector that is not sensitive to neutrons. Therefore, by setting it side by side with a solar cell detector 1 with a conversion film 6, simultaneous measurement at the same location can be performed, which can improve the accuracy of the calculated neutron flux.

[0100] According to the neutron beam detection apparatus A of this embodiment, a neutron beam detection apparatus can be provided that can measure and calculate the flux of a neutron beam with a wider detection range, lower price, wider operating temperature range, and smaller detector setup volume.

[0101] Example

[0102] Prepare a solar cell device (hereinafter referred to as an InGaP solar cell) using a laminate containing p-type and n-type layers made of InGaP. The electrode comprises a thin metal film (less than 0.1 μm) formed on both sides of the laminate for low contact resistance and a relatively thick metal film (greater than 0.1 μm) for reducing electrode resistance. The thin metal film is made of an alloy of gold and tin or zinc, while the relatively thick metal film is made of metals such as molybdenum, ruthenium, iron, lead, and zirconium, which do not produce noise when activated by neutron radiation. A boron plate with a thickness of 0.5 mm, formed by sintering boron powder, is tightly attached to the surface of the InGaP solar cell to manufacture a structure as shown. Figure 2 The diagram shows a neutron detector of the type with a laminated solar cell structure. Meanwhile, an InGaP solar cell without a boron plate, but with the same structure and size, is used as a detector for radiation other than neutrons.

[0103] For InGaP solar cells, irradiation with visible light or reference radiation sources such as alpha particles, beta particles, and gamma rays is performed, and data on the relationship between brightness, flux rates, and output current are obtained in advance. Simultaneously, data on the relationship between irradiation flux and current output reduction are also obtained in advance. Figure 3 The relationship between the flux of alpha rays (the total production rate of alpha particles) and the flux intensity of the neutron beam (the flux of incident neutrons at 50 meV) is shown. Figure 4 The relationship between the flux of alpha particles (the flux of He ion irradiation) and the excitation current (output current) is shown.

[0104] An InGaP solar cell detector with a boron plate and an InGaP solar cell detector without a boron plate are installed side by side. The solar cells of both are set in the neutron generation section of an accelerator-type neutron generation device that generates neutrons by colliding protons with a beryllium plate after accelerating them to 7 MeV. That is, the moderator is set near a 40 mm polyethylene plate at a distance of 14 cm from the beryllium plate.

[0105] The flux of neutrons produced was altered by changing the current of the incident proton beam in an accelerator-type neutron generator, and the output currents from InGaP solar cell detectors with and without boron plates were measured. The relationship between the neutron flux calculated from the proton beam current and the current output of the two InGaP solar cells is as follows: Figure 5 As shown. In the case of this neutron generating device, it can be seen that the current output of the InGaP solar cell without a boron plate is generated by absorbing gamma rays generated simultaneously with neutrons and radiation generated by the radioactive activation of the InGaP solar cell itself.

[0106] It can be said that, from Figure 5 The excitation current value of the InGaP solar cell-type detector with conversion film shown is subtracted from the value of the excitation current value of the detector. Figure 5 The current value obtained from the excitation current value of the InGaP solar cell-type detector without a conversion film, as shown, is the current value generated by neutrons. Therefore, in short, by understanding the aforementioned current value generated by neutrons, from... Figure 4 The relationship shown is Figure 3 By considering the relationships shown, we can determine the flux of neutrons irradiating the InGaP solar cell.

[0107] Furthermore, the energy of the alpha particles generated within the boron plate through neutron absorption is similar to that in... Figure 4 The experiments shown use alpha particles (He ions) with different energies, so the following relationship is obtained to more rigorously control the neutron flux.

[0108] The information stored in the flux calculation unit 16, such as Figure 3 The coefficients representing the relationship between the neutron and alpha particle production rates are shown. Figure 4 The coefficients for the excitation current and the flux value of He ion irradiation shown, and the values ​​representing, for example... Figure 6 The coefficient shown is the current generation ratio calculated or measured in Monte Carlo simulations of InGaP solar cell detectors (normalized to 1 for 200 keV alpha rays in this case).

[0109] In addition, it also possesses, for example Figure 7The spectrum shown represents the relationship between the energy of alpha particles and the generation rate (number of particles generated per unit time) at the interface between the lower surface of the boron film and the upper surface of the InGaP solar cell detector, where alpha particles are emitted from the conversion film (a boron film with a thickness of 0.05 mm), and the energy of the alpha particles is calculated or measured in a Monte Carlo simulation.

[0110] Understandable, based on these Figure 3 , Figure 4 , Figure 6 coefficients and Figure 7 By understanding the relationship between the generation rates and the current value calculated from the difference, the neutron flux can be calculated.

[0111] The method for determining the neutron number from the detected current is described below.

[0112] First, the detection current generated solely by neutrons is calculated by subtracting the current generated by a detector without a conversion film from the current generated by an InGaP solar cell-type detector with a conversion film. This current is generated by... Figure 8 The energy spectrum shown is induced by neutrons.

[0113] like Figure 9 As shown, the probability of producing alpha particles from a boron membrane varies depending on the energy of the neutron. Therefore, by... Figure 8 The value of the middle vertical axis and Figure 9 Multiply the values ​​on the middle and vertical axes to obtain the relative number of alpha particles produced corresponding to the energy of the neutrons in the neutron generating device.

[0114] If we standardize this relative value to 1 when the neutron energy is 50 meV, and then integrate it over the entire energy range, we can find the production ratio when all the alpha particle production numbers produced by neutrons of all energies are converted to the number of alpha particle production numbers produced by neutrons of 50 meV.

[0115] If this value is multiplied by Figure 3 The value of the middle vertical axis reveals the relationship between the incident amount of neutrons in the neutron beam detection device and the total amount of alpha particles generated at the side surface of the boron film solar cell. This relationship is denoted as F.

[0116] On the other hand, the relationship between the number of alpha particles produced by neutron incidence and their energy is... Figure 7 As shown in the image. By... Figure 7 The value of the middle vertical axis multiplied by Figure 6 The value of the middle vertical axis can be used to determine the relative energy of the current generated in the InGaP solar cell with respect to the energy of the alpha particles from the boron film.

[0117] Figure 7 This is a graph representing the spectrum calculated in Monte Carlo simulations, showing the relationship between the energy of an alpha particle generated and emitted by a neutron incident in a conversion film made of a boron film with a thickness of 0.05 mm and the number of alpha particles generated at the surface of the solar cell of the boron film. Figure 7 The spectrum shown is the same for neutrons of any energy, regardless of the energy of the incident neutron.

[0118] If we normalize the aforementioned relative value to 1 when the alpha particle has an energy of 200 keV, and then integrate the value over the entire energy range, this value is the ratio of the current value when the current generated by alpha particles of all energy is converted to the current generated by alpha particles of 200 keV.

[0119] Next, the current value obtained by multiplying the previously calculated value of the detection current generated solely by neutrons by this current value ratio is applied to... Figure 4 The vertical axis in the graph allows us to obtain the corresponding flux value of alpha particles on the horizontal axis. By substituting this flux value into the aforementioned relation F, we can obtain the neutron production (flux).

[0120] Furthermore, in the application of this patent, it is necessary to have the following: Figure 8 The energy spectrum of the produced neutrons shown is sometimes known in advance in applications such as nuclear reactors, where the energy spectrum is an example of an application target. Even when unknown, the energy spectrum can be determined through measurement or nuclear reaction simulation. In these cases, the known energy spectrum of the produced neutrons is used as... Figure 8 Any alternative is acceptable.

[0121] As mentioned above, the sensitivity of the conversion membrane can be changed by adjusting the membrane thickness.

[0122] Figure 12 This is a graph showing the film thickness dependence of the amount of alpha particles emitted from the incident and transmitted sides when 25 meV neutrons are incident on a boron-containing conversion membrane.

[0123] according to Figure 12 When the thickness of the conversion membrane is less than a few μm (e.g., less than 4 μm), the emission of neutrons on the incident side and the transmitted side is almost the same. On the other hand, when the membrane thickness is greater than a few μm (e.g., more than 4 μm), the emission of alpha particles from the incident side saturates, while the emission of alpha particles from the transmitted side decreases with increasing membrane thickness.

[0124] The main reason for the saturation of alpha particle emission on the incident side is that the range of alpha particles in the conversion membrane is several μm. Therefore, alpha particles generated in the portion of the boron-containing conversion membrane that is several μm thick are blocked by the boron-containing conversion membrane and are not emitted.

[0125] The main reason for the reduced emission of alpha particles on the through side is that neutrons are absorbed inside the boron-containing conversion membrane, thus reducing the amount of neutrons reaching the through side. Therefore, by controlling the thickness of the conversion membrane, the sensitivity characteristics and orientation dependence of the detector can be controlled.

[0126] Furthermore, the film thickness dependence of the emission of charged particles or photons from the surface is not limited to boron and alpha particles, but also applies to plates that can convert neutrons into charged particles and photons, such as boron and lithium, boron and gamma rays, lithium and proton beams, lithium and alpha particles, gadolinium and gamma rays, etc.

[0127] Before and after the measurements in this embodiment, the output of the solar cells in the two InGaP solar cell devices used, i.e., the current output when exposed to light, was measured. It was confirmed that no degradation caused by exposure to radiation was found, and no degradation correction was required. In this way, the degradation of the detector caused by solar cells such as InGaP can be investigated by measuring the output of the solar cells using this simple method.

[0128] Figure 13 It means possessing Figure 1 The diagram shows one configuration of the neutron beam measurement system S of the neutron beam detection device A.

[0129] The first solar cell detector 1 and the second solar cell detector 2 are housed in the sensor housing 20. The output lines of the first solar cell detector 1 and the second solar cell detector 2 are respectively connected to the noise filter 25 via an SMA (Sub Miniature Type A) connector 21, a connecting cable 22, and an SMA connector 23. The connecting cable 23 is preferably a shielded cable.

[0130] A portion of the internal wiring in the wiring box 25 of the noise filter 25 is grounded via grounding wire 26. By connecting the output lines of the first solar cell detector 1 and the second solar cell detector 2 to the noise filter 25, noise components of the current generated by the first solar cell detector 1 and the second solar cell detector 2 in a radiation environment can be removed.

[0131] As noise components, one can think of noise from the minute ripple voltage generated by the measurement system, or noise generated by the system being charged by radiation. Noise caused by ripple voltage can be mainly removed by capacitors and low-pass filters. In addition, noise generated by the charging caused by radiation can be removed by grounding the measurement system.

[0132] The output of the noise filter 25 is connected to a microammeter 29 via a BNC connector 27 and a coaxial cable 28. The microammeter 29 is connected to a computing device 31, such as a personal computer, via a digital signal cable 30. The computing device 31 is equipped with... Figure 1 The difference calculation unit 15 and the flux calculation unit 16 are shown.

[0133] The micro-ammeter 29 performs A / D conversion on the current supplied from the output line of the first solar cell detector 1 and the output line of the second solar cell detector 2. The difference calculation unit 15 and the flux calculation unit 16 assembled in the arithmetic unit 31 convert the current signal into flux rate, as previously described. During this conversion, the neutron flux can be calculated using the calibration curve based on the visible light or reference radiation source as previously described.

[0134] The neutron beam measurement system S described above can be described as a system in which the first step is to read the current value, the second step is to read the calibration curve, the third step is to calculate the neutron flux based on the calibration curve and the current, and the fourth step is to output the flux of the neutron beam.

[0135] As an example Figure 13 The personal computer and other computing devices 31 shown are as follows: Figure 14 The device shown includes an input unit 32, a control unit 33, a storage unit 34, and an output unit 35.

[0136] The input unit 32 is, for example, a keyboard for inputting text and numbers, and various information can be input into the control unit 33 or the storage unit 34 through the input unit 32.

[0137] The control unit 33 includes a central processing unit (CPU), random access memory (RAM), read-only memory (ROM), etc., and is capable of performing various numerical calculations, information processing, and equipment control through various programs.

[0138] Storage unit 34 is an information recording medium such as a solid-state drive (SSD) or a hard disk drive (HDD), which can store various programs, information required when the computing unit 36 ​​is executed, such as information pre-stored in the storage unit of the aforementioned throughput computing unit 16 as described above, and results obtained based on various programs and information, or can read the stored content.

[0139] The output unit 35, such as a monitor or printer, can display or print various relationships and other information as described later on the screen or paper as needed, in addition to the various information obtained through the various programs stored in the storage unit 34.

[0140] Furthermore, by pre-storing the required program and various information needed for execution by the computation unit 36 ​​(described later) in the storage unit 34 before executing the program, these programs and information can be read and manipulated at will. In addition, calculation results obtained by executing the program can be stored or retrieved as needed. Alternatively, the storage unit 34 can be configured to communicate with the Internet or a network, allowing it to utilize the storage units, computation units, and prediction units of other personal computers connected to the Internet or a network to perform calculations in the same manner as the arithmetic device 31 and obtain results.

[0141] The information stored in storage unit 34 is, for example, the same as the information previously stored in neutron flux calculation unit 16, which is first information and second information, etc. Furthermore, as previously explained, it is possible to obtain and store information based on the first information. Figure 3 The relationships shown, and the ability to obtain and store information based on the second information. Figure 4 The relationship shown.

[0142] Furthermore, based on this information, the calculation unit 36 ​​can perform the same calculation as the difference calculation unit 15 described previously, performing the difference calculation of the current signals of the current measuring devices 3 and 4 as previously described, and can calculate the difference based on... Figure 3 The relational data shown and Figure 4 The neutron flux is calculated using the relational data shown. Furthermore, the previously explained... Figure 15 As shown in the graph, given that the neutron flux and current follow a proportional relationship based on a power function, the calculation unit 36 ​​can be equipped with the function to calculate the neutron flux by fitting a function.

[0143] In addition, based on Figure 15 The diagram shown indicates that the storage unit 34 and the computing unit 36 ​​can analyze the neutron flux in the nonlinear region based on a quadratic function relationship using the calibration curve of the previously described solar cell detector 1.

[0144] The above procedure uses a first solar cell detector 1 and a radiation detector 2. The first solar cell detector 1 has a conversion film attached to its surface that converts neutrons into photons or any of the charged particle beams selected from alpha particles, protons, lithium nuclei, gamma rays, and beta rays. Current is generated by incident radiation. The radiation detector 2 generates a current that is insensitive to neutrons due to the incident radiation, serving as its output signal. Furthermore, the procedure uses a current meter 3 to detect the current generated by the first solar cell detector 1 and the current generated by the radiation detector 2 as signals.

[0145] Furthermore, the program can be described as a program that enables the computing device (computer) 31 to function as the following units: a comparison unit that compares the current signals detected by the current measuring devices 3 and 4 and generated by the first solar cell detector 1 and the current signals generated by the radiation detector 2 with the current measuring device (flux calculation unit) 36; and a unit that, through the calculation unit (flux calculation unit) 36, corresponds the current signals detected by the current measuring devices 3 and 4 from the solar cell detector 1 and the radiation detector 2 with the relationship between the flux of a predetermined type of incident radiation and the detection current from the solar cell detector and the radiation detector, and calculates the flux of the neutron beam based on the corresponding results.

[0146] Furthermore, similarly, the difference calculation unit 15 and flux calculation unit 16 described above are based on Figure 11 When measurements are performed in environments with high neutron flux and environments with low neutron flux, the measurements can be performed using a program installed in the arithmetic unit 31 in the same manner as the difference calculation unit 15 and the flux calculation unit 16.

[0147] In addition, the difference calculation unit 15 and the flux calculation unit 16 have functions based on those described in the embodiments, such as... Figures 3 to 12 The function of calculating neutron flux based on the relationship shown can be performed by installing the functions of the difference calculation unit 15 and the flux calculation unit 16 as programs in the storage unit 34 and the calculation unit 36, and executing these programs installed in the storage unit 34. The structure described above can be adopted to perform the neutron flux calculation in the same manner as described in the embodiment.

[0148] Industrial applicability

[0149] The neutron beam detection device involved in this invention can be applied to monitor the neutron flux in high-temperature, high-flux environments such as near nuclear reactors.

[0150] In addition, the neutron beam detection device involved in this invention can be applied to monitor the neutron flux in confined environments such as near the neutron generating material of an accelerated neutron generator.

[0151] Symbol Explanation

[0152] A neutron beam detection device

[0153] S-neutron beam detection system

[0154] 1. First solar cell type detector

[0155] 2. Radiation detector (second solar cell type detector)

[0156] 3, 4 Current measuring device

[0157] 5. Flux Calculation Device

[0158] 6. Conversion membrane

[0159] 7 P layers

[0160] 8 N layers

[0161] 9-Laminate

[0162] Electrode layers 10 and 11

[0163] 12 Conversion membrane

[0164] 15. Difference Calculation Department

[0165] 16 Flux Calculation Department

[0166] 25 Noise Filter

[0167] 26 Grounding wire

[0168] 29. Microammeter

[0169] 31. Computing device (personal computer)

[0170] 32 Input Units

[0171] 33 Control Department

[0172] 34 storage units

[0173] 35 Output Units

[0174] 36. Calculation unit.

Claims

1. A neutron beam detection device for detecting neutron beams, characterized in that, have: A solar cell-type detector has a conversion membrane on its surface that converts neutrons into a specified amount of radiation, and generates an electric current by incident radiation through the conversion membrane; A radiation detector, which is configured adjacent to the solar cell-type detector, generates a current that is insensitive to neutrons as an output signal due to the incident radiation. A current measuring device that detects the current generated by the solar cell-type detector due to the incident radiation and the current generated by the radiation detector as signals; as well as The flux calculation unit compares the current signal generated by the solar cell-type detector and detected by the current meter with the current signal generated by the radiation detector. The flux calculation unit has a function of corresponding the current signals detected by the current measuring device from the solar cell detector and the radiation detector to the flux of a predetermined type of incident radiation and the detection current from the solar cell detector and the radiation detector, and calculating the flux of the neutron beam based on the corresponding results.

2. The neutron beam detection device according to claim 1, characterized in that, The solar cell detector is the first solar cell detector. The radiation detector is a second solar cell type detector, which does not include a conversion membrane to convert neutrons into specified radiation. The flux calculation unit calculates the difference between the current signal from the first solar cell detector and the current signal from the second solar cell detector. It has the function of corresponding this difference to the relationship between the flux of a predetermined type of incident neutron and the difference of the detection current from the first solar cell detector, and calculating the flux of the neutron beam based on the corresponding result.

3. The neutron beam detection device according to claim 2, characterized in that, The neutron beam detection device has the function of calculating neutron flux based on a calibration curve pre-stored in the flux calculation unit, which is based on a linear function, a power function, or a quadratic function.

4. The neutron beam detection device according to any one of claims 1-3, characterized in that, The conversion membrane is composed of any of the following: The elemental form of lithium, boron, or gadolinium, wherein lithium, boron, or gadolinium contains isotopes capable of converting neutrons into any of the following: alpha particles, protons, lithium nuclei, gamma rays, and beta rays; or Nitrides, fluorides, or oxides of lithium, boron, or gadolinium, wherein the lithium, boron, or gadolinium contains an isotope capable of converting a neutron into any one of an alpha particle, a proton, a lithium nucleus, gamma rays, or beta rays; or A mixture of any one of lithium, boron or gadolinium and any one of lithium, boron or gadolinium nitrides, fluorides or oxides.

5. The neutron beam detection device according to any one of claims 1-3, characterized in that, The solar cell detector is composed of any of the following: Gallium arsenide, indium phosphide, and cadmium telluride with band gaps of 0.8 eV to 2.2 eV; or Indium gallium phosphide, aluminum gallium arsenide, copper indium selenide sulfide; or Perovskite semiconductors.

6. A neutron beam detection method for detecting neutron beams, characterized in that, include: A solar cell detector and a radiation detector are used, wherein the solar cell detector has a conversion film attached to its surface that converts neutrons into a specified radiation, and an electric current is generated by incident radiation through the conversion film; the radiation detector is arranged adjacent to the solar cell detector and generates an output signal as a current that is insensitive to neutrons due to the incident radiation. The current generated by the solar cell detector due to the incident radiation and the current generated by the radiation detector are detected as signals by a current measuring device; The flux calculation unit compares the current signal generated by the solar cell detector and the current signal generated by the radiation detector, detected by the current meter; and The flux calculation unit uses the current signal detected by the current measuring device from the solar cell detector and the radiation detector to correspond to the relationship between the flux of a predetermined type of incident radiation and the detection current from the solar cell detector and the radiation detector, and calculates the flux of the neutron beam based on the corresponding result.

7. The neutron beam detection method according to claim 6, characterized in that, The solar cell detector is the first solar cell detector. The radiation detector is a second solar cell type detector, which does not include a conversion membrane to convert neutrons into specified radiation. The flux calculation unit calculates the difference between the current signal from the first solar cell detector and the current signal from the second solar cell detector. It then maps this difference to the relationship between the flux of a predetermined type of incident neutron and the difference in the detection current from the first solar cell detector, and calculates the flux of the neutron beam based on the corresponding result.

8. The neutron beam detection method according to claim 7, characterized in that, Also includes: Neutron flux is calculated based on calibration curves pre-stored in the flux calculation unit, which are based on linear, power, or quadratic functions.

9. The neutron beam detection method according to any one of claims 6-8, characterized in that, The conversion membrane is composed of any of the following: The elemental form of lithium, boron, or gadolinium, wherein lithium, boron, or gadolinium contains isotopes capable of converting neutrons into any of the following: alpha particles, protons, lithium nuclei, gamma rays, and beta rays; or Nitrides, fluorides, or oxides of lithium, boron, or gadolinium, wherein the lithium, boron, or gadolinium contains an isotope capable of converting a neutron into any one of an alpha particle, a proton, a lithium nucleus, gamma rays, or beta rays; or A mixture of any one of lithium, boron or gadolinium and any one of lithium, boron or gadolinium nitrides, fluorides or oxides.

10. The neutron beam detection method according to any one of claims 6-8, characterized in that, The solar cell detector is composed of any of the following: Gallium arsenide, indium phosphide, and cadmium telluride with band gaps of 0.8 eV to 2.2 eV; or Indium gallium phosphide, aluminum gallium arsenide, copper indium selenide sulfide; or Perovskite semiconductors.

11. A neutron beam detection procedure, used in a neutron beam detection method for detecting neutron beams, characterized in that, A solar cell detector and a radiation detector are used, wherein the solar cell detector is equipped with a conversion membrane that converts neutrons into a specified radiation, and an electric current is generated by incident radiation through the conversion membrane; the radiation detector is arranged adjacent to the solar cell detector and generates an output signal as a current that is insensitive to neutrons due to the incident radiation. The current generated by the solar cell detector due to the incident radiation and the current generated by the radiation detector are detected by a current measuring device. The flux calculation unit compares the current signal detected by the current meter and the current signal generated by the solar cell detector with the current signal generated by the radiation detector; and The flux calculation unit uses the current signal detected by the current measuring device from the solar cell detector and the radiation detector to correspond to the relationship between the flux of a predetermined type of incident radiation and the detection current from the solar cell detector and the radiation detector, and calculates the flux of the neutron beam based on the corresponding result.

12. The neutron beam detection program according to claim 11, characterized in that, The solar cell detector is the first solar cell detector. The radiation detector is a second solar cell type detector, which does not include a conversion membrane to convert neutrons into specified radiation. The flux calculation unit calculates the difference between the current signal from the first solar cell detector and the current signal from the second solar cell detector. It then maps this difference to the relationship between the flux of a predetermined type of incident neutron and the difference in the detection current from the first solar cell detector, and calculates the flux of the neutron beam based on the corresponding result.

13. The neutron beam detection program according to claim 12, characterized in that, The neutron beam detection program has the function of calculating neutron flux based on a calibration curve pre-stored in the flux calculation unit, which is based on a linear function, a power function, or a quadratic function.

14. The neutron beam detection procedure according to any one of claims 11-13, characterized in that, The conversion membrane is composed of any of the following: The elemental form of lithium, boron, or gadolinium, wherein lithium, boron, or gadolinium contains isotopes capable of converting neutrons into any of the following: alpha particles, protons, lithium nuclei, gamma rays, and beta rays; or Nitrides, fluorides, or oxides of lithium, boron, or gadolinium, wherein the lithium, boron, or gadolinium contains an isotope capable of converting a neutron into any one of an alpha particle, a proton, a lithium nucleus, gamma rays, or beta rays; or A mixture of any one of lithium, boron or gadolinium and any one of lithium, boron or gadolinium nitrides, fluorides or oxides.

15. The neutron beam detection program according to any one of claims 11-13, characterized in that, The solar cell detector is composed of any of the following: Gallium arsenide, indium phosphide, and cadmium telluride with band gaps of 0.8 eV to 2.2 eV; or Indium gallium phosphide, aluminum gallium arsenide, copper indium selenide sulfide; or Perovskite semiconductors.

Images