JP2020091241A - Neutron detection apparatus and neutron detection method - Google Patents

Abstract

To achieve both sensitivity and resolution in neutron detection.SOLUTION: A neutron detection apparatus 11 comprises: a scintillator 12 containing a neutron-reactive material; a plurality of detectors 13 for detecting light emitted by the scintillator 12; a plurality of signal amount acquisition units 14 for acquiring an electric signal on the basis of the light detected by the detectors 13: a total signal amount calculation unit 30 for adding up an amount of electric signals, which are generated at the same time, acquired by the signal amount acquisition units 14 to calculate a total signal amount; a signal discrimination unit 31 for discerning a neutron-reactive material resultant signal caused by reaction of a neutron with the neutron-reactive material from electric signals acquired by the signal amount acquisition units 14 on the basis of the total signal amount; and a light-emitting position calculation unit 32 for calculating a light-emitting position of the scintillator 12 from spatial distribution of the signal amount of the plurality of detectors 13 in connection with the neutron-reactive material resultant signal.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to a neutron detection device and a neutron detection method.

In neutron radiography, neutron diffraction, etc. used in material inspection, a parallel neutron beam is irradiated onto an inspection object, and its reflection and absorption characteristics are measured by a detector. An imaging plate (IP) or the like is generally used as a detector used in neutron radiography. When an imaging plate is used, a certain exposure time is required, so that a still image is generally taken.

On the other hand, in order to obtain measurement data at high speed, there is known a device that creates an image by measuring the number of neutrons one by one with an array detector, using a high-intensity neutron beam source or the like. There is. In the case of such a device, there is a problem that it is affected by radiation outside the measurement target, such as γ-rays generated by a neutron source and an inspection target.

Further, a method is known in which a frame having a plurality of holes is provided on each front surface of a plurality of detectors and an image is created as a neutron signal when signals are simultaneously detected by the plurality of detectors. According to such a method, a clear image can be stably supplied except signals other than neutrons.

In addition, a technique is known in which light from a scintillator is converted by a wavelength shift fiber, and the light is measured at positions separated by a certain distance.

JP, 2007-183149, A JP-A-2002-71816

The above-mentioned conventional technique enables neutron imaging by detecting individual signals of neutrons. However, there is a problem that dead space due to the frame occurs and the detection sensitivity decreases and the resolution deteriorates.Moreover, since the light emission of multiple scintillators is collected collectively by the wavelength shift fiber, multiple signals do not overlap. There was a problem that the application was limited to such strength.

An embodiment of the present invention is for solving the above-mentioned problems, and an object thereof is to achieve both sensitivity and resolution in neutron detection.

The neutron detection device according to the embodiment of the present invention, a scintillator including a first neutron reactive material that reacts with neutrons to emit light, is arranged along the first surface of the scintillator, the light emitted by the scintillator. Of a plurality of detectors to detect the, a plurality of signal amount acquisition unit that acquires an electrical signal based on the light detected by each of the plurality of detectors, of the electrical signal generated at the same time in the signal amount acquisition unit A total signal amount calculation unit that calculates the total signal amount by adding the signal amounts, and based on the total signal amount obtained by the total signal amount calculation unit, from the electrical signal acquired by the signal amount acquisition unit, neutrons And a signal discriminating unit for discriminating a first neutron reactive material-derived signal caused by a reaction between the first neutron reactive material and the first neutron-reactive material, with respect to the first neutron reactive material-derived signal discriminated by the signal discriminating unit, And a light emission position calculation unit that calculates the light emission position of the scintillator from the spatial distribution of the signal amount of the detector.

Further, the neutron detection method according to the embodiment of the present invention, a scintillator including a first neutron reactive material that reacts with neutrons and emits light, is arranged along the first surface of the scintillator, and emits light by the scintillator. A plurality of detectors that detect the light, a plurality of signal amount acquisition units that acquire an electrical signal based on the light detected by each of the plurality of detectors, and the electricity obtained by the plurality of signal amount acquisition units. A neutron detection method using a neutron detection device including a calculation unit that performs calculation based on a signal, wherein the calculation unit sums the signal amounts of the electrical signals generated at the same time in the signal amount acquisition unit. Then, a total signal amount calculation step of calculating a total signal amount, the arithmetic unit, based on the total signal amount obtained in the total signal amount calculation step, from the electrical signal acquired by the signal amount acquisition unit, Regarding the signal discrimination step of discriminating a first neutron reaction material-derived signal resulting from the reaction of neutrons and the first neutron reaction material, and the first neutron reaction material-derived signal discriminated in the signal discrimination step, the plurality of And a light emitting position calculating step of calculating the light emitting position of the scintillator from the spatial distribution of the signal amount of the detector.

According to the embodiments of the present invention, it is possible to achieve both sensitivity and resolution in neutron detection.

The block diagram which shows the structure of the neutron detection apparatus which concerns on the 1st Embodiment of this invention. The graph which shows an example of the output waveform of one detector of the neutron detector which concerns on the 1st Embodiment of this invention. The graph which shows the relationship between the time width and the peak value which exceed the voltage threshold value in the output waveform of the detector of the neutron detection device which concerns on the 1st Embodiment of this invention. The graph which shows an example of the relationship between the detector position and signal amount of the neutron detector which concerns on the 1st Embodiment of this invention. The graph which shows an example of the relationship of the total signal amount and generation frequency in the neutron detection device which concerns on the 1st Embodiment of this invention. The block diagram which shows the structure of the neutron detection apparatus which concerns on the 2nd Embodiment of this invention. The graph which shows an example of the relationship of the total signal amount and generation frequency in the neutron detection apparatus which concerns on the 2nd Embodiment of this invention. The block diagram which shows the structure of the neutron detection apparatus which concerns on the 3rd Embodiment of this invention.

A neutron detection device and a neutron detection method according to embodiments of the present invention will be described below with reference to the drawings. Here, parts that are the same or similar to each other are assigned common reference numerals, and duplicate explanations are omitted.

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of the neutron detection apparatus according to the first embodiment of the present invention. The neutron detection device 11 according to the first embodiment irradiates the inspection object 21 with the neutrons generated by the pulse neutron source 20, and transmits the inspection object 21 or scatters the inspection object 21. It detects neutrons.

The pulsed neutron source 20 is a device that generates pulsed neutrons, and is, for example, an accelerator neutron source or a DT tube.

The neutron detection device 11 includes a plate-shaped scintillator 12, a plurality of detectors 13 arranged along one surface of the scintillator 12, and a plurality of signal amount acquisition units 14 that acquire the signal amounts of the plurality of detectors 13, respectively. The calculation unit 15 processes the electric output signals output from the plurality of signal amount acquisition units 14, and the display unit 16 displays the calculation result by the calculation unit 15.

The scintillator 12 includes a first neutron reactive material that emits light by reacting with neutrons. As the first neutron reactive material, for example, Li-6, B-10, Gd or the like can be applied. Further, a plastic scintillator containing B, LiF, LiCAF, or the like can be applied.

The plurality of detectors 13 are two-dimensionally arranged along one surface of the scintillator 12 (the first surface opposite to the inspection object 21). Each of the detectors 13 is for converting the light emitted from the scintillator 12 into an electric signal and measuring the time and the amount of emitted light. For example, photomultiplier tubes (PMTs) and silicon PMTs (Si-PN) are used. Alternatively, a photodiode (PD), an avalanche photodiode (APD), or the like can be used. It is also possible to use an optical window or an optical grease (not shown) that transmits light between the scintillator 12 and the detector 13 if necessary.

The signal amount acquisition unit 14 acquires the magnitude of the pulse signal obtained by the detector 13, and can measure the charge amount of the pulse signal, the maximum voltage value (peak value), or the like. The signal amount acquisition unit 14 includes, for example, an amplifier that amplifies a signal derived from neutrons and a device that can measure a peak value. For the crest value measurement, for example, a multi-channel analyzer (MCA) using an analog-digital converter (ADC) or the like, or a time over threshold method calculated from time information of pulse signals can be applied.

The calculation unit 15 can be realized by, for example, an electronic computer, and has the functions of a total signal amount calculation unit 30, a signal discrimination unit 31, a light emission position calculation unit 32, and an event intensity calculation unit 33. Have.

The total signal amount calculation unit 30 adds up the signal amounts of the pulse signals generated from the plurality of signal amount acquisition units 14 at the same time. The total signal amount calculation unit 30 acquires the total amount using the ADC or the like after electrically summing the pulse signals even if the data obtained by the signal amount acquisition unit 14 is acquired as digital data. It is also possible to do so.

The signal discriminating unit 31 discriminates signals among the outputs of the total signal amount calculating unit 30 by the signal amount and extracts a specific event. When the output of the total signal amount calculation unit 30 is digital data, it suffices that the comparison calculation with the threshold value can be performed. When the output of the total signal amount calculation unit 30 is an analog signal, a method of evaluating after digitization by a comparator or ADC can be considered. A specific example of the discriminating method in the signal discriminating unit 31 will be described later with reference to FIG.

The light emission position calculation unit 32 calculates the position at which the scintillator 12 emits light from the spatial distribution of the signal amounts of the plurality of detectors 13 for the event discriminated by the signal discrimination unit 31.

The event intensity calculation unit 33 calculates the intensity of the first neutron reactive material-derived signal resulting from the reaction between the neutrons and the first neutron reactive material, based on the outputs of the signal discriminating unit 31 and the light emission position calculating unit 32.

In the neutron detector described above, the neutron emitted from the pulsed neutron source 20 is applied to the inspection object 21. Since neutrons do not have an electric charge, when they enter the inspection target 21, reactions such as elastic scattering, inelastic scattering, and trapping with atomic nuclei in the substance occur. These reaction cross-sections are determined by the energy of neutrons and the type of nuclei of matter, and the larger the cross-section, the easier the reaction.

When neutrons enter the scintillator 12 and react with B-10, Li-6, etc., charged particles such as α particles and ions are generated, and the scintillator 12 partially emits light by these charged particles.

The light emitted from the scintillator 12 is transmitted while being diffused in the scintillator 12 in a substantially isotropic manner, and is incident on a plurality of detectors 13 optically connected to the scintillator 12. Although there is a transmission path, the light transmitted in the scintillator 12 is so high in speed that the light reaching the detector is made incident substantially at the same time, and a signal corresponding to the amount of light reaching the detector 13 is generated. Among the signals generated at the same time, the position with the highest signal amount is close to the point where the neutron and the scintillator 12 have reacted, so the position where the light is emitted can be specified by measuring the signal amount for each detector 13. By calculating the intensity distribution of each reacted position, the intensity distribution of neutrons in the plurality of detectors 13 can be measured.

Specifically, since there is a correlation between the generated charge amount of a signal and the light amount, the signal amount is measured by converting the total charge amount into a peak value with a charge amplifier or a waveform shaping amplifier, and then measuring the peak value, The signal can be read by a high-speed ADC, converted into digital data, and then integrated with digital data to measure the total charge amount.

Alternatively, the Time over Threshold method shown in FIGS. 2 and 3 can be used. FIG. 2 is a graph showing an example of an output waveform of one detector of the neutron detection device according to the first embodiment. FIG. 3 is a graph showing the relationship between the time width exceeding the voltage threshold value and the peak value in the output waveform of the detector of the neutron detection device according to the first embodiment.

As shown in FIG. 2, when the detectors having the same configuration are used, the waveform of the pulse signal generated (the charge amount with respect to time) has a similar shape. By taking advantage of this property and acquiring the time width of the pulse signal exceeding a certain threshold value, the peak value can be obtained from this time width. As shown in FIG. 3, the relational expression between the peak value and the time width is obtained in advance. When the method of estimating the peak value from the time information is used, only a device that detects the presence or absence of a signal can operate without using a complicated device such as an ADC.

Among the signal amounts of the detectors 13 obtained by the signal amount acquisition unit 14, the distributions of those generated at the same time are compared, and the position having the maximum value is calculated by the light emission position calculation unit 32. As a method of obtaining the position having the maximum value, for example, a method of comparing digital data and referring to the center coordinate of the detector number whose maximum value is observed may be used.

As a method of obtaining the maximum value and the maximum position, there is a method shown in FIG. 4, for example. FIG. 4 is a graph showing an example of the relationship between the detector position and the signal amount of the neutron detection device according to the first embodiment. In this method, Fitting is carried out by using the least-squares method or the like based on the spatial distribution of the signal amount, an approximate curve (approximate curved surface) a is obtained, and the center coordinates are calculated by this approximate curve (approximate curved surface) a. .. As a modification of this method, it is also possible to calculate by a method of calculating the centroid of the signal amount from the signal amount for each position.

The light emission location calculated by the light emission position calculation unit 32 is applied to the pixels defined at an arbitrary pitch by the event intensity calculation unit 33, and the intensity (the number of events) distribution for each location is created, so that the positions that have reacted with neutrons Can be measured. Furthermore, when the light emission position is calculated by Fittng or centroid calculation from the spatial distribution of the signal amount, it is possible to define pixels smaller than one detector size, and it is possible to improve the obtained resolution. Become.

Here, an example of the discriminating method by the signal discriminating unit 31 and the like will be described with reference to FIG. FIG. 5 is a graph showing an example of the relationship between the total signal amount and the frequency of occurrence in the neutron detection device according to the first embodiment.

The signal detected by the detector 13 and acquired by the signal amount acquisition unit 14 includes a signal caused by γ rays and the like in addition to a signal caused by neutrons.

When neutrons react with B-10, Li-6, etc., high energy of several MeV or more is applied to the scintillator 12. In the case of the scintillator 12, in many cases, the signal by the γ-ray is limited in energy application to the scintillator 12 to several hundred keV. In particular, as the scintillator 12 becomes thinner, the difference in the magnitude of energy application becomes more remarkable, and the generated signal amount has a distribution having a neutron-derived peak, as shown in FIG.

Therefore, in the present embodiment, among the signal amounts of the detectors 13 acquired by the signal amount acquisition unit 14, the events that have occurred at the same time are added up by the total signal amount calculation unit 30 to calculate the total signal amount. With respect to the obtained total signal amount, the signal discrimination unit 31 can extract the neutron-derived event based on a determination such as whether the signal amount is equal to or more than a certain threshold value. Although the discrimination based on only the signal amount is described, a method of discriminating based on the rise of the pulse signal, the decay time information and the like can also be applied.

According to the present embodiment, without providing a dead space due to a frame or the like on the detector, while discriminating signals such as neutrons and γ rays, the intensity distribution of neutrons can be measured, and sensitivity and resolution can both be achieved. Is possible.

[Second Embodiment]
FIG. 6 is a block diagram showing the configuration of the neutron detection apparatus according to the second embodiment of the present invention. The second embodiment is a modification of the first embodiment, and covers the second surface of the scintillator 12 along a surface (front surface, also referred to as a second surface) opposite to the detectors 13. Thus, the cover member 40 is arranged. The cover member 40 includes a second neutron reactive material that generates electrons, alpha particles, and ions by reacting with neutrons. The second neutron reactive material is, for example, a plate material such as a simple substance of Gd or a metal containing Gd.

Other configurations are similar to those of the first embodiment. However, as will be described later, the function of the signal discriminating unit 31 is different.

Generally, when the neutron intensity distribution is measured using the scintillator 12, although the sensitivity increases when the scintillator 12 is thickened, it becomes difficult to identify the light emission position due to the diffusion of light in the scintillator 12, and the signal such as γ-ray Problems such as being easily affected also occur. Therefore, the thickness of the scintillator 12 generally sacrifices either sensitivity or resolution depending on the application.

In this second embodiment, a cover member 40 containing a second neutral reactive material is installed on the front surface of the scintillator 12 in order to achieve both sensitivity and resolution. When the cover member 40 is irradiated with neutrons, charged particles are generated in the cover member 40. A part of the charged particles enters the scintillator 12, and a part of the scintillator 12 emits light.

When light is generated by the reaction with the first neutron reactive material in the scintillator 12, almost all energy is imparted to the scintillator 12, but in the scintillator 12 caused by the charged particles generated in the cover member 40. The amount of light emitted is small. However, since the light emitting position is always on the surface of the scintillator 12, it is relatively easy to specify the light emitting position.

FIG. 7 is a graph showing an example of the relationship between the total signal amount and the frequency of occurrence in the neutron detection device according to the second embodiment.

In the second embodiment, the total signal amount obtained by the total signal amount calculation unit 30 is a peak derived from the first neutron reactive material (scintillator 12) and a peak derived from the second neutron reactive material (cover member 40). The signal discriminating unit 31 discriminating into three or more types has these two peaks, and the light emitting position calculating unit 32 calculates the light emitting position for each event. At this time, since the event derived from the second neutron reactive material always emits light on the front surface of the scintillator 12 as described above, based on this information, the Fitting function or the like used in the emission position calculation unit 32 is discriminated for each event. It is possible to use the optimized one.

When Gd is used for the second neutron reaction material (cover member 40), the neutron reaction cross section of Gd sharply increases at neutron energy of 0.1 eV or less, whereas the first neutron reaction material (scintillator 12). The reaction cross section of B-10 and Li-6 used in () is inversely proportional to the velocity v of neutrons (proportional to 1/v). Therefore, in the event intensity calculation unit 33, the event derived from the second neutron reactive material and the event derived from the first neutron reactive material are separately calculated, so that additional information can be obtained in addition to the simple intensity distribution. Can be obtained.

For example, when the event intensity derived from the second neutron reactive material is dominant, most of the neutron energy contained in the neutron beam may be dominated by thermal neutrons of 0.1 eV or less, When the event intensity derived from the first neutron reactive material is dominant, thermal neutrons are absorbed by the inspection object 21 and the like, and it is possible to judge that neutrons of 1 eV or more are dominant. ..

On the other hand, when events derived from both neutron reactive materials are observed, it means that in addition to the event reacted by the scintillator 12, the event derived from the second neutron reactive material is also observable, and in the case of only the scintillator 12 The sensitivity can be improved in comparison.

As described above, according to the second embodiment, the presence of the cover member 40 makes it possible to further improve the sensitivity without deteriorating the resolution.

[Third Embodiment]
FIG. 8 is a block diagram showing the configuration of the neutron detection device according to the third embodiment of the present invention. The third embodiment is a modification of the first embodiment, and the neutron detection device 11 has a neutron generation time acquisition unit 50. Furthermore, in the third embodiment, the calculation unit 15 includes a time difference acquisition unit 51, a time discrimination signal strength acquisition unit 52, and an energy-based strength distribution calculation unit 53. Other configurations are the same as those in the first embodiment.

The neutron generation time acquisition unit 50 acquires a signal at the time when neutrons are generated in the pulse neutron source 20. The time difference acquisition unit 51 is capable of measuring relative time, and outputs the signal of the time difference between the time obtained by the neutron generation time acquisition unit 50 and the signals obtained by each of the plurality of signal amount acquisition units 14. get. The time discrimination signal strength acquisition unit 52 acquires the signal strength of the time discrimination based on the output of the light emission position calculation unit 32 and the output of the time difference acquisition unit 51. The energy-specific intensity distribution calculation unit 53 calculates the intensity distribution for each neutron energy based on the output of the time discrimination signal intensity acquisition unit 52.

Since neutrons have different velocities depending on their energy, neutrons having a higher energy among neutrons generated by the pulse neutron source 20 reach the detector 13 earlier. On the other hand, the reaction between neutrons and substances strongly depends on the energy of the neutrons, and there are substances that are easily absorbed in a specific energy region, and there are diffracting substances, so by calculating the intensity distribution for each neutron energy, It is possible to measure materials and events with high resolution.

Therefore, the time difference is calculated using the time difference acquisition unit 51 from the neutron generation time in the pulse neutron source 20 and the time observed in the plurality of detectors 13, and the installation conditions for the pulse neutron source 20 and the plurality of detectors 13 are set. It can be converted into neutron velocity using the flight distance determined by. Furthermore, the velocity of neutrons can be converted into energy of neutrons.

According to the third embodiment, based on the position of each event obtained by the light emission position calculation unit 32 and the calculated neutron energy information, the time discrimination signal strength acquisition unit 52 calculates the intensity distribution with arbitrary time resolution. It will be possible to create. Further, according to the third embodiment, it is possible to create an intensity distribution for each energy of neutrons, and it is possible to accurately obtain data according to the purpose.

[Other Embodiments]
The third embodiment has been described as a modification of the first embodiment. As another embodiment, based on the second embodiment, as a modification thereof, similarly to the third embodiment, the neutron detection device 11 has a neutron generation time acquisition unit 50, and further, the calculation unit 15 is The time difference acquisition unit 51, the time discrimination signal strength acquisition unit 52, and the energy-based intensity distribution calculation unit 53 may be included.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

DESCRIPTION OF SYMBOLS 11... Neutron detector, 12... Scintillator, 13... Detector, 14... Signal amount acquisition part, 15... Arithmetic part, 16... Display part, 20... Pulse neutron source, 21... Inspection object, 30... Total signal amount calculation Part, 31... Signal discrimination part, 32... Emission position calculation part, 33... Event intensity calculation part, 40... Cover member, 50... Neutron generation time acquisition part, 51... Time difference acquisition part, 52... Time discrimination signal strength acquisition part, 53... Energy intensity distribution calculation unit

Claims (10)

A scintillator including a first neutron reactive material that emits light by reacting with neutrons;
A plurality of detectors arranged along the first surface of the scintillator to detect light emitted by the scintillator;
A plurality of signal amount acquisition unit that acquires an electrical signal based on the light detected by each of the plurality of detectors,
A total signal amount calculation unit that calculates the total signal amount by adding the signal amounts of the electric signals generated at the same time in the signal amount acquisition unit,
Based on the total signal amount obtained by the total signal amount calculation unit, from the electric signal acquired by the signal amount acquisition unit, the first neutron reactive material caused by the reaction between neutrons and the first neutron reactive material A signal discriminating section for discriminating the cause signal,
For the first neutron reactive material-derived signal discriminated by the signal discriminating unit, from the spatial distribution of the signal amount of the plurality of detectors, a light emitting position calculating unit for calculating the light emitting position of the scintillator,
A neutron detection device comprising: Based on the output of the signal discrimination unit and the light emission position calculation unit, an event intensity calculation unit that calculates the intensity of the first neutron reactive material-induced signal due to the reaction between neutrons and the first neutron reactive material,
The neutron detection device according to claim 1, further comprising: At least three of the plurality of detectors are arranged along the first surface of the scintillator,
The light emission position calculation unit, based on a function representing the relationship between the position of each of the plurality of detectors and the signal strength of each of the plurality of detectors, the maximum intensity position where the signal intensity is maximum and the maximum intensity position thereof. 3. The neutron detection device according to claim 1 or 2, wherein the signal intensity in Eq. The signal amount acquisition unit estimates a pulse wave height based on time information of a pulse-like time change pattern of an electric signal acquired by each of the plurality of detectors. The neutron detection device according to any one of 1. The neutron detector according to any one of claims 1 to 4, wherein the first neutron reactive material is a material containing at least one of Li and B. A second neutron disposed along a second surface opposite the first surface with respect to the scintillator and reacting with a neutron to generate at least one of an electron, an alpha particle and an ion. Further comprising a cover member containing a reaction material,
The first neutron reactive material is configured to emit light when at least one of an electron, an alpha particle, and an ion generated in the cover member is input to the scintillator. A neutron detection device according to claim 5. The signal discriminating unit is based on the total signal amount obtained by the total signal amount calculating unit, from an electric signal acquired by the signal amount acquiring unit, due to a reaction between neutrons and the first neutron reactive material. A first neutron-reactive-material-derived signal, a second neutron-reactive-material-derived signal resulting from a reaction between neutrons and the second neutron-reactive material, the first neutron-reactive material-derived signal, and the second neutron-reactive material-derived signal The neutron detection device according to claim 6, wherein the neutron detection device discriminates signals other than signals. The neutron detection device according to claim 6 or 7, wherein the second neutron reactive material is a material containing Gd. A neutron generation time acquisition unit that acquires the pulse generation time of the pulse neutrons generated by the pulse neutron source,
The pulse generation time acquired by the neutron generation time acquisition unit, and a time difference acquisition unit that acquires a time difference between the signal generation time in each of the plurality of detectors,
For each of the plurality of detectors, based on the time difference acquired by the electric signal and the time difference acquisition unit acquired by the signal amount acquisition unit, a time-discrimination signal strength acquisition unit that acquires time-discrimination signal strength,
The neutron detection device according to any one of claims 1 to 8, further comprising: A scintillator including a first neutron reactive material that emits light by reacting with neutrons;
A plurality of detectors arranged along the first surface of the scintillator to detect light emitted by the scintillator;
A plurality of signal amount acquisition unit that acquires an electrical signal based on the light detected by each of the plurality of detectors,
An arithmetic unit that performs an arithmetic operation based on the electric signals obtained by the plurality of signal amount acquisition units,
A neutron detection method using a neutron detection device comprising:
A total signal amount calculation step in which the calculation unit calculates the total signal amount by summing the signal amounts of the electric signals generated at the same time in the signal amount acquisition unit;
The calculation unit, based on the total signal amount obtained in the total signal amount calculation step, from the electrical signal acquired by the signal amount acquisition unit, due to the reaction of neutrons and the first neutron reactive material A signal discriminating step for discriminating the signal originating from the first neutron reactive material,
For the first neutron reactive material-derived signal discriminated in the signal discrimination step, from the spatial distribution of the signal amount of the plurality of detectors, a light emission position calculation step of calculating the light emission position of the scintillator,
A neutron detection method comprising:

Images