JP7154845B2 - Particle beam inspection device, particle beam inspection container, particle beam inspection method - Google Patents

Description

An embodiment of the present invention relates to an inspection technique for particle beams emitted from a particle beam irradiation apparatus.

Cancer treatment using particle beams is expected to realize efficient treatment because the dose can be concentrated. In this treatment, charged particles are accelerated to a predetermined energy by an accelerator and irradiated to the human body. When the human body is irradiated with these charged particles, the energy of the charged particles is abruptly imparted to the substance due to the Coulomb interaction.

This energy has a sharp maximum, called the Bragg peak, at a certain depth in the body corresponding to the incident energy of the charged particle. Then, at the position where this Bragg peak appears, a large amount of energy is pinpointed. Radicals generated by the ionization action of this substance act on DNA and destroy the growth function of tumors.

In cancer treatment with particle beams, the principle of Bragg peak expression is applied to concentrate the radiation dose on the tumor while suppressing radiation on healthy cells. A scanning method has been put to practical use in which a particle beam is narrowed down to a narrow irradiation beam called a pencil beam and irradiation is performed according to the shape of the tumor.

This scanning method first irradiates two-dimensionally perpendicular to the emission axis while changing the emission direction of the particle beam, and then changes the energy of the particle beam to change the depth direction of the irradiation position. Irradiate. This is repeated to irradiate the particle beam three-dimensionally according to the shape of the tumor, minimizing radiation damage to healthy tissue.

Here, in order to accurately irradiate the target position of the human body tissue with the particle beam, the particle beam irradiation apparatus needs to be periodically checked for its irradiation accuracy. Specifically, it is necessary to confirm the relationship between the energy of the particle beam and its irradiation depth, that is, the position at which the Bragg peak appears. Furthermore, when scanning the particle beam two-dimensionally, three-dimensionally, or four-dimensionally, it is necessary to confirm that the scanning plane called the irradiation field is within the set range.

Conventionally, these particle beam irradiation accuracy confirmation tests are performed by installing a water phantom at the isocenter of the particle beam irradiation device and measuring the radiation generated in the process of passing the particle beam through the water when the particle beam is irradiated. It is done by

WO2016/148269

In the conventional confirmation inspection of particle beam irradiation accuracy, the ionization chamber is moved in the irradiation direction while the particle beam is irradiated to the water phantom, and the intensity of the radiation is measured. Then, it was confirmed whether or not the intensity distribution of radiation with respect to the depth of water fell within a predetermined set range.

Regarding the confirmation of the irradiation field, multiple ionization chambers were placed outside the water phantom on a plane orthogonal to the irradiation direction, and the width and height of the irradiation field were determined from the two-dimensional distribution of radiation obtained by scanning the particle beam. I was confirming.

However, conventional confirmatory examinations are performed while the water phantom is placed at the isocenter of the particle beam irradiation device and the particle beam is continuously irradiated. there was a problem. In addition, it takes time to obtain the results of confirmation tests, multiple ionization chambers are required to measure the radiation in confirming the irradiation field, and the curved surface of the irradiation field, which is considered important in the scanning method, There were problems such as difficulty in confirmation.

The embodiments of the present invention have been made in consideration of such circumstances, and it is an object of the present invention to provide a technique for easily and highly accurately inspecting the irradiation accuracy of a particle beam emitted from a particle beam irradiation device. .

In a particle beam inspection device, a substance whose absorbance characteristics change due to the ionization action of a particle beam incident from a particle beam irradiation device , and a substance filled with the substance and arranged at the isocenter of the particle beam irradiation device to irradiate the particle beam from one direction a light beam output unit for outputting a light beam from a light source in a direction crossing the direction of incidence of the particle beam; and a light receiving element that receives the light beam that has passed through the substance and outputs a light intensity signal of the light beam. a light intensity input unit for inputting, and the light source and the light source and the A movement driving unit that relatively moves the light receiving element, and a display unit that displays the position and shape of the Bragg peak appearing in the substance together with the incident area .

An embodiment of the present invention provides a technique for easily and highly accurately inspecting the irradiation accuracy of a particle beam emitted from a particle beam irradiation apparatus.

1 is a perspective view showing an embodiment of a particle beam inspection container irradiated with a particle beam; FIG. (A) Vertical cross-sectional view of a particle beam inspection apparatus according to an embodiment of the present invention, (B) Same, horizontal cross-sectional view. (A) A two-dimensional image of a substance in which a particle beam is incident to develop a Bragg peak, and (B) a graph showing the absorbance distribution along the center line of the incident area of the particle beam. (A) A two-dimensional image of a substance in which a particle beam with varying energy is incident to develop an expanded Bragg peak (SOBP), and (B) a graph showing the absorbance distribution along the center line of the incident region of the particle beam. FIG. 10 is a perspective view showing a particle beam inspection container irradiated with particle beams by changing the incident direction; FIG. 2 is a cross-sectional view of a particle beam inspection apparatus in which a plurality of light receiving elements are arranged; (A) A diagram in which the XYZ coordinate system is set in the particle beam inspection container irradiated with the particle beam by changing the incident direction, (B) a cross-sectional view of the irradiation field of the particle beam represented by the XZ coordinate plane, (C) ) A graph showing the absorbance distribution of the irradiation field expressed in the XZ coordinate plane.

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing an embodiment of a particle beam inspection container (hereinafter referred to as "first container 11") irradiated with a particle beam 16. As shown in FIG. The first container 11, which is a component of the particle beam inspection apparatus 10 (FIG. 2), is filled with a substance 17 whose absorbance characteristics in the visible region change due to the ionization action of the particle beam 16 incident from the particle beam irradiation apparatus 15. . This substance 17 is composed of a gelling agent that gels an aqueous solution and a molecular bonding group cut and oxidized by radicals generated by ionizing water by the particle beam 16 selectively absorbs light in a specific wavelength region and develops color. and a coloring agent that causes

As a result, when the particle beam 16 is incident on the substance 17, the incident region 18 is oxidized by the generated radicals, and the absorbance characteristic is changed. When the incident region 18 is irradiated with light, the light in a specific wavelength region is absorbed, and the light in the remaining wavelengths is also scattered and the intensity of the transmitted light is attenuated. . At a position where a large amount of energy is released from the particle beam 16, such as the position where the Bragg peak 13 is generated, a large amount of radicals are generated and the degree of oxidation increases, so the absorbance is observed to be even higher.

A specific composition example of the substance 17 filled in the first container 11 is water, gelatin or agar as a gelling agent substance, a mixture of a leuco dye and an organic halogen compound as a coloring agent capable of developing color by oxidation, and montmorillonite. and an inorganic substance containing a clay mineral as a main component and a silicate compound.

When the particle beam 16 is incident on such a substance 17, the incident region 18 exhibits blue under white light. Therefore, by passing light having a spectrum in the wavelength range of 400 nm to 700 nm through the incident region 18, the absorbance can be detected with high sensitivity, and the accuracy of specifying the position of the Bragg peak 13 can be improved.

Furthermore, since the substance 17 contains a leuco dye, light with a wavelength of around 590 nm is absorbed with high efficiency. Therefore, by adopting a monochromatic light source or a laser light source having an emission spectrum near 590 nm, the absorbance of the incident region 18 can be detected with high sensitivity, and the accuracy of specifying the position of the Bragg peak 13 is improved. can be made

The composition of the substance 17 filled in the first container 11 is not limited to those described above, and any substance that causes a change in absorbance characteristics due to the irradiation of the particle beam 16 can be suitably adopted. If there is an absorbance characteristic of the region, it is more desirable because it can be determined visually. As the substance 17 that can be employed, a Fricke gel dosimeter that develops color by dispersing gelatin or agar and a compound containing divalent iron ions in water and oxidizing the divalent iron to trivalent iron by the ionization action of radiation, A polymer gel dosimeter in which a polymer precipitates due to a polymerization reaction, a dye plastic dosimeter in which a dye is dispersed in a polymer simulating water, and a PVA-KI gel indicator that utilizes the oxidation of iodine and the color reaction between PVA and iodine. etc. can also be applied.

The substance 17 filled in the first container 11 can irreversibly change the absorbance characteristics of the incident region 18 of the particle beam 16 by short-time irradiation. Therefore, the first container 11 can be separated from the particle beam irradiation device 15 to observe the Bragg peak 13 of the substance 17, and the particle beam irradiation device 15 will not be occupied for a long time.

Examples of the particle beam 16 include proton beams and heavy particle beams, and examples of the particle beam irradiation device 15 include devices for human treatment, but are not particularly limited.

FIG. 2(A) is a vertical cross-sectional view of the particle beam inspection apparatus 10 according to the embodiment, and FIG. 2(B) is a horizontal cross-sectional view thereof. The particle beam inspection apparatus 10 includes a mechanical configuration system 30 including at least the first container 11 , the light source 31 and the light receiving element 35 , and a control system 20 therefor.

The control system 20 includes a control device in which a processor such as a dedicated chip, FPGA (Field Programmable Gate Array), GPU (Graphics Processing Unit), or CPU (Central Processing Unit) is highly integrated, and a ROM (Read Only Memory) and RAM (Random Access Memory), external storage devices such as HDD (Hard Disk Drive) and SSD (Solid State Drive), display devices such as displays, and input devices such as mice and keyboards. , and a communication I/F, and can be realized with a hardware configuration using a normal computer.

The control system 20 of the particle beam inspection apparatus 10 includes a light beam output unit 21 that outputs a light beam 32 in the visible region from a light source 31, and a light receiving element 35 that receives the light beam 32 that has passed through the substance 17 and outputs a light intensity signal 36 of the light beam 32. A light intensity input portion 22 to be inputted and a light source 31 with respect to the first container 11 so as to intersect the incident region 18 of the particle beam 16 (FIG. 1) and to move the light beam 32 along the direction of the incident region 18. and a movement driving unit 25 that relatively moves the light receiving element 35 .

The mechanical configuration system 30 of the particle beam inspection apparatus 10 further includes a second container 12 in which the liquid 19 in which the first container 11 is immersed is accommodated and in which the light source 31 and the light receiving element 35 are arranged outside. . By providing such a second container 12, the medium in contact with the curved side wall of the first container 11 becomes the liquid 19 whose refractive index is closer to the side wall than air. This suppresses the light ray 32 from being reflected by the surface of the side wall when passing through the side wall of the first container 11 . Since the side wall of the second container 12 is flat, the light ray 32 is less reflected when it passes through the side wall of the second container 12 .

The material constituting the first container 11 and the second container 12 is not particularly limited, but should be transparent with little intensity attenuation with respect to the effective wavelength of the light beam 32 output from the light source 31 and detected by the light receiving element 35. is desirable. The liquid 19 contained in the second container 12 is preferably water, but is not particularly limited as long as it is transparent and has little intensity attenuation with respect to the effective wavelength of the light beam 32 .

The light beam 32 output from the light source 31 may be continuous light having a continuous spectrum in the wavelength range of 400 nm to 700 nm, or monochromatic light or laser light having a bright line spectrum in the wavelength range of 400 nm to 700 nm. Although the light source 31 shown in FIG. 2B is composed of a single point light source, it may be configured by arranging a plurality of point light sources 31 . In this case, the respective point light sources 31 are arranged such that the optical axes of the light beams 32 output from each are parallel to each other. Also, the light source 31 outputs the light beam 32 upon receiving power from the light beam output unit 21 .

The light receiving element 35 detects the intensity of the light beam 32 that has passed through the substance 17 filled in the first container 11 . The light receiving element 35 then transmits a light intensity signal 36 corresponding to the intensity of the detected light beam 32 to the light intensity input section 22 . The intensity of the light ray 32 detected by the light receiving element 35 is attenuated in the process of passing through the substance 17 . This attenuated light intensity is defined as absorbance.

Although the light receiving element 35 shown in FIG. 2B is composed of a single element, it may be configured by arranging a plurality of elements. In this case, by having one or more semiconductor-type light-receiving elements 35, not only the intensity of the light beam 32 that has passed through the substance 17 but also the intensity and distribution of the scattered light can be detected, and the position of the Bragg peak 13 can be determined with high accuracy. can be observed at Also, the arrangement of the plurality of light receiving elements 35 should be dense and the arrangement width should be larger than the maximum diameter of the incident region 18 at the position of the Bragg peak 13 . As a result, when the incident area 18 is imaged, a wide angle of view and a fine image can be obtained.

The light source 31 and the light receiving element 35 are fixed to the support member 37 so that the distance between them is constant and the optical axes of the light beams 32 are aligned. This support member 37 is connected to a linear motion mechanism (not shown) provided on the outer wall of the second container 12 . This linear motion mechanism (not shown) is moved downward in FIG. Move along the longitudinal direction.

Regarding the relative linear movement of the light ray 32 and the substance 17, the case where the light ray 32 is linearly moved while the substance 17 is stationary is exemplified. be. Also, as the means for supporting the light source 31 and the light receiving element 35, the support member 37 formed in a ring is exemplified, but there is no particular limitation, as long as it can be raised and lowered while maintaining the interval and inclination of the light beams 32. adopted as appropriate.

The mechanical configuration system 30 of the particle beam inspection apparatus 10 further includes a mounting table 38 on which the first container 11 filled with the substance 17 is mounted. Then, the mounting table 38 rotates around the rotating shaft 39 with respect to the bottom surface of the second container 12 . The mounting table 38 rotates about a rotation axis 39 that intersects with the light beam 32 in response to a rotation signal 34 output from the rotation drive unit 26 . Thereby, the first container 11 rotates relative to the light source 31 and the light receiving element 35 .

Regarding the relative rotation between the light ray 32 and the substance 17, the light ray 32 is made stationary and the substance 17 is rotated.

When the light beam 32 is rotated in this way, the supporting member 37 has a circular shape when viewed from above, although not shown. go around. In this case, the second container 12 has a cylindrical shape, and the circular cross section of the side wall, the circular track of the support member 37, and the circular cross section of the first container 11 are arranged so as to form concentric circles.

The image data generator 27 generates two-dimensional image data or three-dimensional image data of the incident region 18 based on the light intensity signal 36 input while moving the light source 31 and the light receiving element 35 relative to the first container 11. It is generated.

When only the support member 37 is linearly moved without operating the mounting table 38, the image data generator 27 expresses the projection image of the incident area 18 in pixels based on the light intensity signal 36 and the movement signal 33. Generate two-dimensional image data. Then, when both the mounting table 38 and the support member 37 are linearly moved and rotated, a three-dimensional image of the incident region 18 is represented by voxels based on the light intensity signal 36, the movement signal 33, and the rotation signal 34. Generate image data.

The three-dimensional image data of the incident area 18 can also be converted into a two-dimensional image of an arbitrary cross section or a two-dimensional image obtained by projecting voxels onto an arbitrary projection plane. The two-dimensional image data or three-dimensional image data generated in this manner is transferred to the display unit 28 and visually displayed in coordinates. In the display section 28, pixels or voxels in areas where the absorbance is high are displayed with high brightness or a color corresponding to the absorbance, so that the appearance position and shape of the Bragg peak can be accurately observed.

FIG. 3(A) is a two-dimensional image of the substance 17 in which the particle beam 16 (FIG. 1) is incident and the Bragg peak 13a is developed, and FIG. It is a graph which shows absorbance distribution. A first inspection method for the particle beam 16 emitted by the particle beam irradiation device 15 will now be described.

In the first inspection method, the particle beam 16 is emitted from the particle beam irradiation device 15 shown in FIG. In this case, due to the ionization action of the particle beam 16, a Bragg peak appears at the same position, and the absorbance characteristic of the substance 17 at that portion changes intensively. has a sharp peak. By observing such an absorbance curve and an image of the incident region 18a, it is possible to judge the probability of appearance position and shape of the Bragg peak.

FIG. 4(A) is a two-dimensional image of a substance in which a particle beam 16 (FIG. 1) with varied energy is incident to develop an expanded Bragg peak 13b (SOBP), and FIG. It is a graph which shows the absorbance distribution along the incident region 18b. A second inspection method for the particle beam 16 emitted by the particle beam irradiation device 15 will now be described.

In the second inspection method, a particle beam 16 is emitted by changing the energy from the particle beam irradiation device 15 shown in FIG. In this case, due to the ionization action of the particle beam 16, each Bragg peak shifts at the depth position corresponding to the energy, and a spread out Bragg peak (SOBP) appears. Since the absorbance characteristics of the substance 17 where the SOBP is expressed change in the same manner, the absorbance at the corresponding position has a broad peak as shown in FIG. 4(B). By observing such an absorbance curve and an image of the incident region 18b, it is possible to determine the likelihood of the appearance position and shape of the SOBP.

FIG. 5 is a perspective view showing the particle beam inspection container (first container 11) irradiated with the particle beam 16 with the incident direction changed. FIG. 6 is a cross-sectional view of a particle beam inspection system in which a plurality of light receiving elements 35 are arranged. As a method of irradiating the particle beam 16 by changing the incident direction in this way, the wobbler method and the scanning method can be mentioned.

Here, the scanning method is a method in which the particle beam 16 with constant energy is scanned in the range direction by a bending magnet (not shown). The wobbler method is a method in which the particle beam 16 is rotated and spread by wobbler electromagnets whose magnetic field directions are orthogonal to each other, and the particle beam 16 is further scattered by a scatterer downstream thereof.

When irradiation is performed by changing the incident direction of the particle beam 16 using the wobbler method, the scanning method, or the like, an irradiation field 13c is formed in which the Bragg peak expression position spreads in a plane. In order to finely image the irradiation field 13c that spreads in a planar shape, as shown in FIG. It consists of a dense array of multiple semiconductor detectors with individual outputs.

The array width W of the plurality of light receiving elements 35 is set larger than the maximum length L of the region in which the absorbance characteristics are changed by the ionization action of the particle beam 16 (FIG. 1) in the cross section of the substance 17 perpendicular to the incident axis of the particle beam. It is As a result, when the irradiation field 13c of the Bragg peak is imaged, a wide angle of view and a fine image can be obtained.

FIG. 7A is a diagram in which an XYZ coordinate system is set in a particle beam inspection container irradiated with a particle beam while changing the incident direction, and FIG. FIG. 7C is a cross-sectional view of the irradiation field 13c, and FIG. 7C is a graph showing the absorbance distribution of the irradiation field 13c represented on the XZ coordinate plane. A third inspection method for the particle beam 16 emitted by the particle beam irradiation device 15 will now be described.

A third inspection method uses a wobbler method or a scanning method to emit a particle beam 16 with constant energy and varying directions from the particle beam irradiation device 15 shown in FIG. be incident on the In this case, due to the ionization action of the particle beam 16, each Bragg peak appears in a curved surface at a position corresponding to the energy and the emission direction.

As shown in FIG. 7B, this curved irradiation field has a radius of curvature around the point where the emission direction changes. Then, as shown in FIG. 7C, the absorbance characteristic of the irradiation field having this radius of curvature has a constant value. By observing such an absorbance curve and the image of the incident region 18c, it is possible to determine the likelihood of the appearing position of the irradiation field and the shape of the curved surface.

Although illustration is omitted, as a fourth inspection method, the first container 11 is moved stepwise with respect to the isocenter of the particle beam irradiation device 15, the particle beam 16 with varied energy is emitted, and the position is determined. There is a method of making the light incident on the substance 17 by shifting it. In this case, incident regions 18 corresponding in number to the number of steps in which the first container 11 is moved are formed in the substance 17, and a plurality of Bragg peaks appear at depth positions corresponding to the irradiated energy. By observing images of a plurality of incident regions 18 in this manner, it is possible to determine the likelihood of appearance positions and shapes of Bragg peaks formed by changing the incident energy.

According to the particle beam inspection apparatus of at least one embodiment described above, the irradiation accuracy of the particle beam emitted from the particle beam irradiation apparatus can be easily improved by using a substance whose absorbance characteristics change due to the ionization action of the particle beam. And it becomes possible to inspect with high accuracy.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, as well as the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 10... Particle beam inspection apparatus, 11... 1st container, 12... 2nd container, 13... Bragg peak, 13a... Bragg peak, 13b... Extended Bragg peak (SOBP), 13c... Radiation field, 15... Particle beam irradiation apparatus, 16 Particle beam 17 Substance 18 (18a, 18b, 18c) Incidence area 19 Liquid 20 Control system 21 Light beam output unit 22 Light intensity input unit 25 Movement drive unit 26 Rotation drive unit 27 Image data generation unit 28 Display unit 30 Machine configuration system 31 Point light source 31 Light source 32 Light beam 33 Movement signal 34 Rotation signal 35 Light receiving element , 36... Light intensity signal, 37... Supporting member, 38... Mounting table, 39... Rotary shaft.

Claims (13)

a substance whose absorbance characteristics change three-dimensionally due to the ionization action of a particle beam incident from a particle beam irradiation device ;
a first container filled with the substance and arranged at the isocenter of the particle beam irradiation device to allow the particle beam to enter from one direction ;
a light beam output unit for outputting a light beam from a light source in a direction crossing the direction of incidence of the particle beam;
a light intensity input unit for inputting a light intensity signal of the light beam from a light receiving element that inputs the light beam that has passed through the substance;
moving the light source and the light receiving element relative to the first container so as to intersect the incident area of the particle beam and move the light beam along the incident direction of the particle beam in the incident area; a moving drive unit that causes
A particle beam inspection apparatus , comprising: a display unit that displays the position and shape of a Bragg peak appearing in the substance together with the incident area . In the particle beam inspection device according to claim 1 ,
A particle beam inspection apparatus further comprising a rotation drive unit that rotates the first container relative to the light source and the light receiving element about an axis intersecting the direction of the light beam. In the particle beam inspection device according to claim 2 ,
an image data generator for generating two-dimensional image data or three-dimensional image data of the incident area based on the light intensity signal input while moving the light source and the light receiving element relative to the first container; , further comprising a particle beam inspection device. In the particle beam inspection apparatus according to any one of claims 1 to 3 ,
A particle beam inspection apparatus further comprising a second container in which a liquid for immersing the first container is accommodated and in which the light source and the light receiving element are arranged outside. In the particle beam inspection apparatus according to any one of claims 1 to 4 ,
The substance filled in the first container is
a gelling agent that gels the aqueous solution;
A particle beam inspection apparatus, comprising: a coloring agent that selectively absorbs light in a specific wavelength region and develops color by molecular bonding groups cut and oxidized by radicals generated when water is ionized by the particle beam. In the particle beam inspection apparatus according to any one of claims 1 to 5 ,
A particle beam inspection apparatus wherein the light beam output from the light source is continuous light having a continuous spectrum in a wavelength range of 400 nm to 700 nm, or monochromatic light or laser light having a bright line spectrum in a wavelength range of 400 nm to 700 nm. In the particle beam inspection apparatus according to claim 6 ,
A particle beam inspection apparatus in which the light receiving element is an assembly of a plurality of semiconductor detectors that individually output the light intensity signal according to the intensity of the input light beam. In the particle beam inspection apparatus according to claim 7 ,
The array width of the plurality of light-receiving elements is set larger than the maximum length of a region in which absorbance characteristics are changed by the ionization action of the particle beam in a cross section of the substance perpendicular to the incident axis of the particle beam. inspection equipment. A particle beam inspection container that is the first container constituting the particle beam inspection apparatus according to any one of claims 1 to 8 . a step of emitting the particle beam from the particle beam irradiation device and making the particle beam incident on the substance filled in the first container constituting the particle beam inspection device according to claim 1;
A particle beam inspection method, comprising: observing a position of a Bragg peak from a portion of the substance in which the absorbance characteristics have changed due to the ionizing action of the particle beam. a step of emitting the particle beam by changing the energy from the particle beam irradiation device and making the particle beam incident on the substance filled in the first container constituting the particle beam inspection device according to claim 1;
and a step of observing a shape of an extended Bragg peak (SOBP) from a portion of the substance in which the absorbance characteristics have changed due to the ionizing action of the particle beam. a step of emitting the particle beam from the particle beam irradiation device while changing the direction of the particle beam, and causing the particle beam to enter the substance filled in the first container constituting the particle beam inspection device according to claim 1;
A particle beam inspection method, comprising: observing a shape of an irradiation field from a portion of the substance in which the absorbance characteristic is changed by an ionization action of the particle beam. a step of emitting the particle beam from the particle beam irradiation device and making the particle beam incident on the substance filled in the first container constituting the particle beam inspection device according to claim 1;
a step of moving the position of the first container to emit the particle beam from the particle beam irradiation device, shifting the position and causing the particle beam to enter the substance;
A particle beam inspection method, comprising: observing positions of a plurality of Bragg peaks from a portion of the substance in which the absorbance characteristics have changed due to the ionization action of the particle beam.

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