JP2013098090A - X-ray radiation device and x-ray radiation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate X-ray beams for MRT without requiring large-scale facilities.SOLUTION: An X-ray radiation device includes: a metal target 5 that emits bremsstrahlung X-rays as an X-ray beam X when irradiated with an electron beam; an X-ray block body 6 that has a slit-like X-ray transmission part 6a and is disposed on the downstream side of the metal target 5 in an emission direction of the X-ray beam X so that part of the X-ray beam X passes through the X-ray transmission part 6a and the X-ray block body blocks the X-ray beam X incident on an area other than the X-ray transmission part 6a; and an electron beam generation device that irradiates the metal target 5 with such an electron beam that a diameter of a generation point of the X-ray beam X to be emitted is smaller than a length of an entry part of the X-ray transmission part 6a in a longitudinal direction.

Description

  The present invention relates to an X-ray irradiation apparatus that irradiates X-rays and an X-ray irradiation method in the X-ray irradiation apparatus.

  In recent years, as a cancer treatment method, a microbeam obtained by transmitting an X-ray beam through a slit with a width of μm is generated, and this microbeam is irradiated to a tumor (MRT; Microbeam Radiation Therapy). Has been proposed. It has been reported by various experiments that this therapeutic method can provide an excellent therapeutic effect in which only cancer cells can be destroyed without destroying normal cells.

  As a technique related to this MRT, Non-Patent Documents 1 and 2 utilize a phenomenon in which electromagnetic waves are emitted when charged particles such as high-energy electrons are bent by a Lorentz force in a magnetic field. A method of generating an X-ray beam for MRT by transmitting light (X-ray beam) through a plurality of linear radiation shielding slits is disclosed.

  On the other hand, in Patent Document 1, in a linear accelerator for accelerating an electron beam, the beam current, beam velocity, and beam diameter of the electron beam are measured, and the magnetic field by the solenoid coil is controlled according to those measured values, A method for reducing emittance is disclosed.

Japanese Patent Laid-Open No. 6-76991

"Difference between tumor suppressor gene p53 normal type cancer cell and above type cancer cell in cell lethal effect and recovery phenomenon on slit-shaped microbeam", [online], 2010, [September 30, 2011] Search], Internet <URL: http://www.spring8.or.jp/pdf/en/MBTU/H20/14.pdf> “Basic research on microbeam therapy”, NIRS News, No. 134, [online], 2008, [searched on September 30, 2011], Internet <URL: http: //www.nirs.go. jp / report / nirs_news / 200801 / hik10p.htm>

  In order to implement the techniques disclosed in Non-Patent Documents 1 and 2, a large-scale synchrotron radiation facility for generating synchrotron radiation is required, so the places where the techniques can be implemented are limited. In order for cancer patients who are the most common cause of death in Japan to receive MRT using this technology, they must go to a large-scale synchrotron radiation facility, which is inconvenient. Therefore, it is desired that an apparatus for MRT treatment be installed in a general hospital.

  However, in order to generate an X-ray beam for MRT, a radiation shielding slit having a long depth and a narrow width is used. However, it can be obtained from a general radiation source except for a parallel X-ray beam obtained from the above-mentioned radiation light. The X-ray beam (cone beam) that is used reduces the transmission efficiency of the slit. Therefore, in order to obtain a dose for treatment, enormous radiation source output is required, and there are problems in constructing the device such as heat generation and shielding. Many occur.

  The present invention has been made in view of the above problems, and an object thereof is to provide an X-ray irradiation apparatus and an X-ray irradiation method capable of generating an X-ray beam for MRT without requiring a large-scale facility. To do.

  In order to achieve the above object, an X-ray irradiation apparatus according to the present invention includes a metal target that emits a braking X-ray as an X-ray beam when irradiated with an electron beam, and a slit-like shape. The X-ray transmission part of the metal target so that a part of the X-ray beam is transmitted through the X-ray transmission part and shields the X-ray beam incident on a region other than the X-ray transmission part. An X-ray shield disposed on the downstream side of the X-ray beam emission direction, and an electron beam in which the diameter of the emitted X-ray beam generation point is shorter than the length along the longitudinal direction of the entrance portion of the X-ray transmission portion And an electron beam generator for irradiating the metal target.

  According to the X-ray irradiation apparatus of claim 1, when the electron beam is irradiated by the metal target, the braking X-ray is emitted as the X-ray beam, and has a slit-shaped X-ray transmission part and A part of the X-ray beam is transmitted through the X-ray transmission part by the X-ray shield disposed on the downstream side in the emission direction of the X-ray beam, and the X-ray beam incident on a region other than the X-ray transmission part is transmitted. Shielded. Here, in the present invention, the electron beam generator causes an electron beam having a diameter of a generation point of the emitted X-ray beam to be shorter than the length along the longitudinal direction of the entrance portion of the X-ray transmission portion. Irradiated.

  As described above, according to the X-ray irradiation apparatus of the first aspect, the metal target is irradiated with the electron beam whose diameter of the generation point of the X-ray beam is shorter than the length along the longitudinal direction of the entrance portion of the X-ray transmission portion. As a result, an X-ray beam is generated, and the X-ray beam is incident on the slit-shaped X-ray transmission part. As a result, a high-dose linear X-ray beam can be generated, resulting in a large-scale facility. It is possible to generate an X-ray beam for MRT without the need for

  By the way, when the shape of the X-ray beam is narrowed using the X-ray shield, in order to increase the conversion efficiency of the X-ray transmission part, the X-ray beam X-ray generation point (hereinafter, also simply referred to as a focal point). ) Should be as small as possible.

  However, at present, it is difficult to increase the conversion efficiency due to the fact that the entrance portion has a small width and a long slit in the depth direction. For this reason, it is necessary to generate a high-intensity X-ray beam. End up. In this case, there is a problem in that heat generation at the X-ray focal point in the metal target becomes very large, and the X-ray focal point part in the target may be destroyed.

  Therefore, in the X-ray irradiation apparatus according to the present invention, as described in claim 2, the shape of the electron beam emitted by the electron beam generator is changed to the X-ray before the metal target is irradiated. You may make it further comprise the control means which controls so that it may become a long shape in the direction along the longitudinal direction of the inlet_port | entrance part of a line | wire transmission part. Thereby, concentration of the electron energy in a metal target can be avoided and there exists an effect that destruction of a metal target can be prevented.

  In the X-ray irradiation apparatus according to the present invention, as described in claim 3, the irradiation position of the electron beam emitted from the electron beam generation apparatus to the metal target is that of the X-ray transmission unit. Control means for controlling to move in a direction corresponding to the longitudinal direction of the entrance portion, or, as described in claim 4, by changing an emission angle of the electron beam emitted from the electron beam generator. In addition, control means for controlling the irradiation position of the electron beam to the metal target may be provided.

  In the X-ray irradiation apparatus according to the present invention, as described in claim 5, when the control unit changes the emission angle of the electron beam, the charge amount changes according to the speed of the change. In addition, the electron beam may be controlled. This produces an effect that an electron beam with a uniform dose can be generated.

  In the X-ray irradiation apparatus according to the present invention, as described in claim 6, the metal target has a minimum thickness that does not damage the metal target by the electron beam when the electron beam is irradiated. You may make it form so that it may become. As a result, the effect of electron diffusion in the metal target can be reduced, and as a result, the conversion efficiency can be further improved.

  Further, in the X-ray irradiation apparatus according to the present invention, as described in claim 7, the X-ray irradiation apparatus is provided so as to be thermally coupled to a case or an external case of the electron beam generator and to be in contact with at least a part of the metal target. You may make it further comprise the heat conductive member made. As a result, it is possible to prevent the metal target from being destroyed as a result of suppressing the temperature increase of the target.

  In the X-ray irradiation apparatus according to the present invention, as described in claim 8, the heat conducting member may be provided so as to surround a region irradiated with the X-ray beam on the metal target. good. Thereby, there exists an effect that destruction of a metal target can be prevented more effectively.

  Moreover, in the X-ray irradiation apparatus according to the present invention, as described in claim 9, the X-ray transmission part may have an entrance part with a width of 20 μm or more and 1 mm or less. This produces an effect that an X-ray beam suitable for MRT can be generated.

  In the X-ray irradiation apparatus according to the present invention, as described in claim 10, the dose of the electron beam is such that the dose of the X-ray beam transmitted through the X-ray transmission part is 1 Gy or more and 1000 Gy or less. The dose of the X-ray beam transmitted without being shielded by the region other than the X-ray transmission part of the X-ray shield is 1/1000 or more of the dose of the X-ray beam transmitted through the X-ray transmission part. You may make it determine so that it may become 10 or less. This produces an effect that an X-ray beam suitable for MRT can be generated.

  Moreover, in the X-ray irradiation apparatus according to the present invention, as described in claim 11, the X-ray beam emitted from the metal target is an X-ray beam expanding in a cone shape, and the X-ray shield includes A plurality of the X-ray transmission portions may be provided at different positions so that the generation point of the X-ray beam is positioned on the extension in the depth direction of the X-ray transmission portion. Thereby, there is an effect that an X-ray beam for MRT can be efficiently generated from the X-ray beam emitted from the metal target.

  Moreover, in the X-ray irradiation apparatus according to the present invention, as described in claim 12, the X-ray shield may be formed by combining a plurality of flat shield members. Thereby, there exists an effect that an X-ray shield can be manufactured simply.

  Moreover, in the X-ray irradiation apparatus according to the present invention, as set forth in claim 13, each of the plurality of X-ray transmission portions is provided as an exit portion that is emitted from an entrance portion where the X-ray beam is incident. You may make it form so that it may become gradually wide toward it. Thereby, there exists an effect that the transmittance | permeability in the X-ray transmissive part of the X-ray beam which injected into the X-ray shield can be improved.

  Moreover, in the X-ray irradiation apparatus according to the present invention, as described in claim 14, the X-ray irradiation apparatus may further include a first adjustment unit that adjusts the widths of the entrance portions of the plurality of X-ray transmission portions. . Thereby, there exists an effect that the width | variety of the entrance part of an X-ray transmissive part can be adjusted according to the dose etc. of an X-ray beam.

  Further, in the X-ray irradiation apparatus according to the present invention, as described in claim 15, the mutual positional relationship between the generation point of the X-ray beam and the plurality of X-ray transmission portions of the X-ray shield is adjusted. You may make it further provide the 2nd adjustment means to do. Thereby, there is an effect that the mutual positional relationship between the generation point of the X-ray beam and the X-ray transmission part can be adjusted.

  Moreover, in the X-ray irradiation apparatus according to the present invention, as described in claim 16, a plurality of shielding members each having a surface forming the X-ray transmission part between corresponding surfaces of adjacent shielding members. May be arranged so that the generation point of the X-ray beam is positioned on the extension in the depth direction of each of the formed X-ray transmission parts. Thereby, there exists an effect that an X-ray shield can be manufactured simply.

  On the other hand, in order to achieve the above object, the X-ray irradiation method according to claim 17 includes a metal target that emits a braking X-ray as an X-ray beam when irradiated with an electron beam, and the X-ray of the metal target. There is a slit-shaped X-ray transmission part whose entrance part width is smaller than the beam diameter when the X-ray beam is incident on the downstream side of the beam emission direction, and a part of the X-ray beam is transmitted through the X-ray transmission part. An X-ray shield that shields an X-ray beam incident on a region other than the X-ray transmission portion, and a diameter of a generation point of the emitted X-ray beam when the electron target is irradiated with the electron beam. An X-ray irradiation method in an X-ray irradiation apparatus, comprising: an electron beam generator that irradiates the target with an electron beam shorter than the length along the longitudinal direction of the entrance portion of the X-ray transmission section; A control step for controlling the shape of the electron beam emitted by the apparatus so as to be long in a direction along the longitudinal direction of the entrance portion of the X-ray transmission portion; and the shape controlled in the control step An emission step of emitting the X-ray beam by irradiating the metal target with the electron target; and a transmission step of transmitting the X-ray beam emitted in the emission step through the X-ray transmission unit. X-ray irradiation method.

  Therefore, according to the X-ray irradiation method of the seventeenth aspect, since it operates in the same manner as the invention of the second aspect, the MRT does not require a large-scale facility as in the second aspect. As a result, an X-ray beam can be generated, and destruction of the metal target can be prevented.

  In order to achieve the above object, the X-ray irradiation method according to claim 18 includes a metal target that emits a braking X-ray as an X-ray beam when irradiated with an electron beam, and the X-ray of the metal target. There is a slit-shaped X-ray transmission part whose entrance part width is smaller than the beam diameter when the X-ray beam is incident on the downstream side of the beam emission direction, and a part of the X-ray beam is transmitted through the X-ray transmission part. An X-ray shield that shields an X-ray beam incident on a region other than the X-ray transmission portion, and a diameter of a generation point of the emitted X-ray beam when the electron target is irradiated with the electron beam. An X-ray irradiation method in an X-ray irradiation apparatus, comprising: an electron beam generator that irradiates the target with an electron beam shorter than the length along the longitudinal direction of the entrance portion of the X-ray transmission section; A control step of controlling the irradiation position of the electron beam emitted by the apparatus in a direction along the longitudinal direction of the entrance portion of the X-ray transmission portion; and the control step An emission step of emitting the X-ray beam by irradiating the controlled electron beam to the metal target, and a transmission step of transmitting the X-ray beam emitted in the emission step through the X-ray transmission unit And an X-ray irradiation method.

  Therefore, according to the X-ray irradiation method of the 18th aspect, since it operates in the same manner as the invention of the 3rd aspect, the MRT without requiring a large-scale facility as in the case of the 3rd aspect of the present invention. As a result, an X-ray beam can be generated, and destruction of the metal target can be prevented.

  According to the present invention, it is possible to generate an X-ray beam for MRT without requiring a large-scale facility.

It is a top view which shows the whole structure of the X-ray irradiation apparatus which concerns on embodiment. It is a perspective view which shows the shielding body which concerns on embodiment. (A) is a graph which shows the relationship between the position of the X-ray beam which permeate | transmitted the shield, and relative dose in the X-ray irradiation apparatus which concerns on 1st Embodiment, (B) concerns on 1st Embodiment. In an X-ray irradiation apparatus, it is a figure which shows the shape seen from the emission direction of the X-ray beam which permeate | transmitted the shield. It is the schematic which shows the principal part of the X-ray irradiation apparatus 1 which concerns on 1st Embodiment, (A) is a schematic top view, (B) is a schematic side view. It is a perspective view which shows the principal part of the X-ray irradiation apparatus which concerns on 1st Embodiment. (A) is a figure which shows the shape seen from the radiation | emission direction of the X-ray beam just before injecting into the shield in the X-ray irradiation apparatus which concerns on 1st Embodiment, (B) concerns on 1st Embodiment. It is a figure which shows the shape seen from the radiation | emission direction of the X-ray beam immediately after permeate | transmitting the shield in an X-ray irradiation apparatus. It is the schematic which shows the principal part of the X-ray irradiation apparatus which concerns on 2nd Embodiment, (A) is a schematic top view, (B) is a schematic side view. It is a figure which shows the example of arrangement | positioning of the deflection magnet in the X-ray irradiation apparatus which concerns on 2nd Embodiment. It is a perspective view which shows the principal part of the X-ray irradiation apparatus which concerns on 2nd Embodiment. (A) is a figure which shows the shape seen from the radiation | emission direction of the X-ray beam immediately before injecting into the shield in the X-ray irradiation apparatus which concerns on 2nd Embodiment, (B) concerns on 2nd Embodiment. It is a figure which shows the shape seen from the radiation | emission direction of the X-ray beam immediately after permeate | transmitting the shield in an X-ray irradiation apparatus. It is the schematic which shows the principal part of the X-ray irradiation apparatus which concerns on 3rd Embodiment, (A) is an upper surface schematic diagram, (B) is a side surface schematic diagram. It is a figure which shows the structure of the alternating current magnet in the X-ray irradiation apparatus which concerns on 3rd Embodiment, (A) is a perspective view, (B) is a schematic side view. It is a flowchart which shows the flow of a process of the X-ray control processing program performed by the X-ray irradiation apparatus which concerns on this embodiment. It is a perspective view which shows the principal part of the X-ray irradiation apparatus which concerns on 3rd Embodiment. (A) is a figure which shows the shape seen from the radiation | emission direction of the X-ray beam just before injecting into the shield in the X-ray irradiation apparatus which concerns on 3rd Embodiment, (B) concerns on 3rd Embodiment. It is a figure which shows the shape seen from the radiation | emission direction of the X-ray beam immediately after permeate | transmitting the shield in an X-ray irradiation apparatus. In the X-ray irradiation apparatus which concerns on 3rd Embodiment, it is a graph which shows an example of the voltage applied to an alternating current magnet. (A) is a front view which shows the structure of the target of the X-ray irradiation apparatus which concerns on 4th Embodiment, (B) is an enlarged side view which shows the structure of the target of the X-ray irradiation apparatus which concerns on 4th Embodiment. It is. It is the schematic which shows the principal part of the X-ray irradiation apparatus which concerns on 5th Embodiment, (A) is a schematic top view, (B) is a schematic side view. It is a perspective view which shows the shield of the X-ray irradiation apparatus which concerns on 5th Embodiment. (A) is a schematic top view which shows the principal part of the X-ray irradiation apparatus which concerns on 5th Embodiment, (B) is the outline which shows another example of the principal part of the X-ray irradiation apparatus which concerns on 5th Embodiment. It is a top view. (A) is a graph which shows the relationship between the position of the X-ray beam which permeate | transmitted the shield, and relative dose in the X-ray irradiation apparatus which concerns on 5th Embodiment, (B) concerns on 5th Embodiment. In an X-ray irradiation apparatus, it is a figure which shows the shape seen from the emission direction of the X-ray beam which permeate | transmitted the shield. It is a figure which shows the beam profile of the X-ray beam which permeate | transmitted the shield in the X-ray irradiation apparatus which concerns on 5th Embodiment.

[First Embodiment]
Hereinafter, the X-ray irradiation apparatus according to the first embodiment will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a top view showing the overall configuration of the X-ray irradiation apparatus 1 according to the first embodiment.

  As shown in FIG. 1, an X-ray irradiation apparatus 1 includes an electron gun 2a that generates an electron beam e, a low emittance accelerator 2b that accelerates the generated electron beam e while reducing the emittance, and accelerated low emittance electrons. A beam duct 2 for guiding a beam (hereinafter also simply referred to as an electron beam e) to the outside is provided. Further, the X-ray irradiation apparatus 1 includes a control device 3. The control device 3 generates the electron beam e by the electron gun 2a, the beam current of the electron beam e accelerated by the low emittance accelerator 2b, the beam velocity, and the like. Control of measurement of the beam diameter and adjustment of the magnetic field by a solenoid coil according to the measured values is performed.

  The electron beam e that has reached the inside of the beam duct 2 is emitted to the outside through the electron emission window 4. The electron exit window 4 is formed of a thin metal plate such as Ti or Be. The inside of the beam duct 2 is kept in vacuum, and the electron emission window 4 partitions the inside of the beam duct 2 from the outside so as not to hinder the movement of electrons as much as possible when air enters the inside of the beam duct 2. Yes.

  A target 5 is provided on the downstream side of the beam duct 2 in the emission direction of the electron beam e. The target 5 is formed of a heavy metal such as W or Ta, and when the electron beam e irradiated through the electron emission window 4 collides, generates a braking X-ray in response to the collision. The generated braking X-ray spreads conically in front of the collision point and is emitted as an X-ray beam.

  The target 5 is formed to have a minimum thickness that is not damaged when the electron beam e emitted from the beam duct 2 is irradiated. Thereby, the thickness of the target 5 can be made as thin as possible while preventing damage to the target 5 by reducing the influence of electron diffusion in the target 5.

  On the downstream side of the target 5 in the emission direction of the X-ray beam X, a shield 6 having a slit 6a that transmits a part of the X-ray beam X is provided. The slit 6a is formed so that the width of the entrance is smaller than the beam diameter of the X-ray beam X.

  FIG. 2 is a perspective view showing the shield 6 according to the first embodiment. As shown in FIG. 2, the shield 6 according to the present embodiment is a substantially rectangular parallelepiped, and each of the shields 6 is composed of a plurality of heavy metals (W in the present embodiment) each having a high ability to shield the X-ray beam X (this embodiment). In the embodiment, two shielding units 6b are combined.

  In the shield 6 according to the present embodiment, the two shield units 6b are arranged so that one surface of the shield unit 6b faces each other with a predetermined gap therebetween, and the slit 6a that transmits the X-ray beam X through the gap. Is formed.

  As described above, in the X-ray irradiation apparatus 1 according to this embodiment, the X-ray beam X is applied to the shield 6 on which the slit 6a is formed, and the X-ray beam X of the irradiated X-ray beam X is transmitted through the slit 6a. By irradiating a patient with a shaped X-ray beam X, it can be used for MRT.

  As a result of intensive studies by the present inventors, when MRT is performed using the X-ray beam X, if the width of the irradiated X-ray beam is 20 μm or more and 1 mm or less, only the cell nucleus disappears without causing destruction of the tissue. Therefore, the width of the slit 6a is preferably 20 μm or more and 1 mm or less.

  Similarly, as a result of intensive studies by the present inventors, when performing MRT, the dose of the electron beam e is 1 Gy or more and 1000 Gy or less of the X-ray beam X transmitted through the slit 6a, and the shield. It is preferable that the dose of the X-ray beam X transmitted without being shielded in the region other than the slit 6a is 6 to 1/1000 to 1/10 of the dose of the X-ray beam X transmitted through the slit 6a. It has been found.

  The shielding body 6 is not limited to the above-described configuration, and each shielding unit 6b is formed in a shape having one or more planar portions (in this embodiment, the planar portion 6c in FIG. 2), and each shielding unit 6b. It is only necessary that the slit 6a is formed by arranging the flat portions 6c so as to face each other so as to be substantially parallel and to form a gap. Alternatively, the shield 6 may be composed of one shield unit 6b, and a slit that penetrates the shield unit 6b in the depth direction may be provided.

  Moreover, the slit 6a is not limited to the said gap | interval, You may be formed with the raw material which has a permeability | transmittance to a X-ray. In this case, the material is arranged between the adjacent shielding units 6b instead of the gap.

  FIG. 3A is a graph showing the relationship between the position of the X-ray beam X transmitted through the shield 6 and the relative dose in the X-ray irradiation apparatus 1 according to the first embodiment, and FIG. In the X-ray irradiation apparatus 1 which concerns on 1st Embodiment, it is a figure which shows an example of the shape seen from the radiation | emission direction of the X-ray beam X which permeate | transmitted the shield 6. FIG.

  As shown in FIG. 3A, since the X-ray beam X incident on the shield 6 transmits only the X-ray incident on the slit 6a, it has a sharp peak at the position where the slit 6a is provided in the x direction. As shown in FIG. 3B, a linear X-ray beam X having a shape substantially matching the shape of the entrance of the slit 6a is formed.

  Next, the operation of this embodiment will be described.

  In the X-ray irradiation apparatus 1 according to the present embodiment, one linear X-ray beam X is generated using the shield 6 having only one slit 6a, and is positioned with respect to the irradiation target region of the patient. A case will be described in which MRT is performed by irradiating a plurality of times while shifting.

  4A and 4B are schematic views showing the main part of the X-ray irradiation apparatus 1 according to the first embodiment, where FIG. 4A is a schematic top view and FIG. 4B is a schematic side view. As shown in FIGS. 4A and 4B, the X-ray beam X emitted from the target 5 is incident on the shield 6 disposed downstream of the X-ray beam X, and is incident on the shield 6. After the focused X-ray beam X is focused in the x direction by the shield 6, the linear X-ray beam X obtained thereby is irradiated onto the tumor C.

  FIG. 5 is a perspective view showing a main part of the X-ray irradiation apparatus 1 according to the first embodiment. FIG. 6A is a diagram showing a shape viewed from the emission direction of the X-ray beam X immediately before entering the shield 6 in the X-ray irradiation apparatus 1 according to the first embodiment, and FIG. FIG. 4 is a diagram showing a shape viewed from the emission direction of the X-ray beam X immediately after passing through the shield 6 in the X-ray irradiation apparatus 1 according to the first embodiment.

  As shown in FIG. 5, the X-ray beam X radiated by colliding with the target 5 expands in a conical shape. Therefore, as shown in FIG. 6A, the X-ray beam X just before entering the shield 6 is shown. The shape seen from the emission direction is circular. On the other hand, since the X-ray beam X incident on the shield 6 is narrowed in a linear shape by the shield 6, the emission direction of the X-ray beam X immediately after entering the shield 6 as shown in FIG. The shape seen from is linear.

  In the X-ray irradiation apparatus 1 according to the present embodiment, one linear X-ray beam X is generated using the shield 6 having only one slit 6a, and is positioned with respect to the irradiation target region of the patient. However, the present invention is not limited to this, and a plurality of linear X-ray beams are generated at a time using a shield having a plurality of slits. It is good also as a form which irradiates X-ray beam X to a wide area | region.

  In addition, when an electron beam accelerator that does not reduce the emittance of the electron beam is used, the beam diameter of the electron beam becomes large, so that the focal point at the target is increased, the focal brightness of the same charge is reduced, and X is transmitted through the slit. The dose will decrease.

  Therefore, in the X-ray irradiation apparatus 1 according to this embodiment, the beam diameter of the electron beam e emitted from the electron emission window 4, that is, the diameter of the focal point of the X-ray beam X corresponding thereto is the length of the entrance portion of the slit 6a. It is controlled by the control device 3 so as to be shorter than the length along the direction (y direction). Further, it is preferable that the focal point of the X-ray beam X is controlled to be not more than twice the width of the slit 6a (short direction, ie, the length along the x direction). Accordingly, it is possible to prevent a decrease in the X-ray dose transmitted through the slit by preventing the focal luminance of the same charge from being lowered, and an excellent therapeutic effect can be obtained by irradiating the patient with the X-ray beam X.

[Second Embodiment]
Hereinafter, the X-ray irradiation apparatus 1A according to the second embodiment will be described in detail with reference to the accompanying drawings. An X-ray irradiation apparatus 1A according to the second embodiment is provided with a deflection magnet 7 around the beam duct 2 in the X-ray irradiation apparatus 1 according to the first embodiment. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 7 is a schematic diagram showing the main part of the X-ray irradiation apparatus 1A according to the second embodiment, (A) is a schematic top view, and (B) is a schematic side view. As shown in FIGS. 7A and 7B, in the X-ray irradiation apparatus 1 </ b> A of the second embodiment, a deflection magnet 7 is provided around the beam duct 2.

  FIG. 8 is a diagram illustrating an arrangement example of the deflection magnet 7 in the X-ray irradiation apparatus 1A according to the second embodiment. As shown in FIG. 8, the deflection magnet 7 is a quadrupole electromagnet, and includes two N magnets 7a and two S magnets 7b. On the same plane perpendicular to the emission direction of the electron beam e, the N magnets 7a are arranged to face each other with the electron beam e sandwiched in a direction inclined by 45 degrees from the x direction, and the S magnet. 7b is arranged so as to face each other across the electron beam e in a direction perpendicular to the N magnet 7a. By converging the electron beam e in the x direction by the deflecting magnet 7, the electron beam e is stretched in the y direction and becomes a linear shape that is long in the y direction.

  FIG. 9 is a perspective view showing a main part of the X-ray irradiation apparatus 1A according to the second embodiment. FIG. 10A is a diagram showing a shape viewed from the emission direction of the X-ray beam X immediately before entering the shield 6 in the X-ray irradiation apparatus 1A according to the second embodiment, and FIG. (A) is a figure which shows the shape seen from the radiation | emission direction of the X-ray beam X just after permeate | transmitting the shielding body 6 in X-ray irradiation apparatus 1A which concerns on 2nd Embodiment.

  As shown in FIG. 9, since the electron beam e collides with the target 5 in the state stretched in the y direction by the deflecting magnet 7, the X-ray beam X emitted from the target 5 spreads in a conical shape. As shown to (A), the shape seen from the emission direction of the X-ray beam X just before entering the shield 6 becomes an ellipse stretched in the y direction. On the other hand, since the X-ray beam X incident on the shield 6 is narrowed by the shield 6 into a linear shape, the emission direction of the X-ray beam X immediately after entering the shield 6 as shown in FIG. The shape seen from is linear.

  Thus, the electron beam e adjusted so that the focal point diameter of the X-ray beam X is shorter than the length along the longitudinal direction of the entrance portion of the slit 6 a is formed into the shape of the slit 6 a before colliding with the target 5. In addition, by stretching in the y direction, concentration of electron energy in the target 5 is reduced, and damage to the target 5 can be prevented.

  Further, by reducing the shape of the X-ray beam X viewed from the exit direction to the shape of the entrance of the slit 6a of the shield 6, the number of X-ray beams X that are shielded by the shielding unit 6b and discarded wastefully is reduced. As a result of the increase of the X-ray beam X transmitted through the slit 6a, the tumor C can be irradiated with a higher dose of the X-ray beam X. Further, by reducing the focal point of the X-ray beam X (corresponding to the beam diameter of the electron beam e) (in the present embodiment, the diameter of the electron beam e is shorter than the length along the longitudinal direction of the slit 6a), the slit 6a. By increasing the amount of electrons of the electron beam e that contributes to the generation of the X-ray beam X that passes through the X-ray beam, even if the electron density per unit time is lowered, a high-power X-ray beam can be produced without reducing the plate beam conversion efficiency. Can be generated.

  In the X-ray irradiation apparatus 1A according to the second embodiment, the deflecting magnet 7 having a quadrupole electromagnet is applied. However, the present invention is not limited to this, and the deflecting magnet 7 having a permanent magnet may be applied. good. In this case, it is comprised similarly to the above by two N magnets and two S magnets.

[Third Embodiment]
Hereinafter, the X-ray irradiation apparatus 1B according to the third embodiment will be described in detail with reference to the accompanying drawings. The X-ray irradiation apparatus 1B according to the third embodiment is provided with an AC magnet 8 instead of the deflection magnet 7 around the beam duct 2 in the X-ray irradiation apparatus 1A according to the second embodiment. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment and 2nd Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 11 is a schematic diagram illustrating a main part of the X-ray irradiation apparatus 1B according to the third embodiment, (A) is a schematic top view, and (B) is a schematic side view. As shown in FIGS. 11A and 11B, the X-ray irradiation apparatus 1 </ b> B of the second embodiment is provided with an AC magnet 8 connected to the control device 3 around the beam duct 2. The control device 3 includes at least a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory).

  FIGS. 12A and 12B are diagrams showing the configuration of the AC magnet 8 in the X-ray irradiation apparatus 1B according to the third embodiment, where FIG. 12A is a perspective view and FIG. 12B is a schematic side view. As shown in FIGS. 12A and 12B, the AC magnet 8 is magnetized by passing a current through the coil 8 b based on the control of the control device 3, and one end is an N pole, The other end has the polarity of the south pole.

  The AC magnet 8 of the X-ray irradiation apparatus 1B according to the present embodiment is such that both ends thereof face each other across the electron beam e in the y direction on the same plane perpendicular to the emission direction of the electron beam e. Be placed. In a state where no current flows through the AC magnet 8, the electron beam e goes straight along the incident direction as shown in FIG. 12B, but one of the AC magnets 8 is controlled by the control device 3. When the current is controlled to flow through the coil 8b so that the end is an N pole and the other end is an S pole, the traveling direction of the electron beam e is as shown in FIG. 12 (B). Is bent according to Fleming's left hand rule.

  Further, from this state, the control device 3 controls the one end to change from the north pole to the south pole so that the current flowing through the coil 8b changes so that the other end changes from the south to the north pole. Then, as shown in (c) of FIG. 12B, the traveling direction of the electron beam e is bent to the opposite side of the above (b) with respect to the incident direction according to Fleming's law. By changing the polarity of the AC magnet 8 in this way, the emission angle of the electron beam e is changed to sweep in the y direction, and the irradiation position of the electron beam e on the target 5 is swept in the y direction.

  Here, the flow when the X-ray irradiation apparatus 1B according to the present embodiment performs the X-ray control process will be described. FIG. 13 is a flowchart showing the flow of processing of an X-ray control processing program executed by the CPU of the control device 3 of the AC magnet 8 of the X-ray irradiation device 1B according to the present embodiment. It is stored in advance in a predetermined area of a ROM which is a recording medium provided.

  In step S101, the control device 3 applies a voltage having a predetermined voltage value in one direction of the coil 8b. The predetermined voltage value is a predetermined voltage value, and information indicating the voltage value is stored in the ROM of the control device 3.

  In step S103, the control device 3 applies a voltage having a predetermined voltage value in the other direction of the coil 8b. The predetermined voltage value is a predetermined voltage value (in this embodiment, the same value as the predetermined voltage value in step S101), and information indicating the voltage value is stored in the ROM of the control device 3. Yes.

  In step S105, the control device 3 determines whether or not the voltage control end timing has come. In the X-ray irradiation apparatus 1B according to the present embodiment, the voltage control end timing is stored in the ROM of the control apparatus 3 by setting a predetermined period as a period during which the patient is irradiated with the X-ray beam X. ing. Note that the voltage control end timing is not limited to this. For example, the voltage control end timing may be specified based on a user instruction input.

  As described above, in the X-ray irradiation apparatus 1B according to the present embodiment, the process of steps S101 to S105 causes the AC magnet 8 to generate a magnetic field and continuously switch the polarities at both ends, thereby changing the electron beam e. Sweep in the y direction.

  FIG. 14 is a perspective view showing a main part of the X-ray irradiation apparatus 1B according to the third embodiment. FIG. 15A is a diagram showing a shape viewed from the emission direction of the X-ray beam X immediately before entering the shield 6 in the X-ray irradiation apparatus 1B according to the third embodiment, and FIG. (A) is a figure which shows the shape seen from the radiation | emission direction of the X-ray beam X immediately after permeate | transmitting the shield 6 in X-ray irradiation apparatus 1B which concerns on 3rd Embodiment.

  As shown in FIG. 14, the electron beam e collides with the target 5 while being swept in the y direction by the AC magnet 8, and the X-ray beam X emitted from the target 5 thereby expands in a conical shape. As shown to (A), the shape seen from the emission direction of the X-ray beam X just before entering the shield 6 is a shape in which a circular shape is swept in the y direction. On the other hand, since the X-ray beam X incident on the shield 6 is narrowed into a line by the shield 6, the shape of the X-ray beam X immediately after entering the shield 6 is as shown in FIG. The line shape matches the shape of the entrance of the slit 6a.

  Thus, the electron beam e adjusted so that the focal point diameter of the X-ray beam X is shorter than the length along the longitudinal direction of the entrance portion of the slit 6 a is formed into the shape of the slit 6 a before colliding with the target 5. In addition, by sweeping in the y direction, the concentration of electron energy in the target 5 is reduced, and damage to the target 5 can be prevented.

  Similarly to the second embodiment, the shape viewed from the emission direction of the X-ray beam X is brought close to the shape of the entrance of the slit 6a of the shield 6, so that it is shielded by the shield unit 6b and is wasted. As a result of increasing the number of X-ray beams X transmitted through the slit 6a by reducing the number of X-ray beams X, the tumor C can be irradiated with a higher dose of X-ray beam X. Further, by reducing the focal point of the X-ray beam X (in this embodiment, the diameter of the electron beam e is shorter than the length along the longitudinal direction of the slit 6a), the X-ray beam X transmitted through the slit 6a is generated. By increasing the amount of electrons of the contributing electron beam e, it is possible to generate a high-power X-ray beam without reducing the plate beam conversion efficiency even if the electron density per unit time is lowered.

  By the way, when the electron beam e is swept in the y direction, the electron density is generally higher at the center side in the sweep range of the electron beam e than at both end sides. On the other hand, when a sine wave voltage is applied to the coil 8b, the electron density at both ends in the sweep range of the electron beam e increases.

  Therefore, in the X-ray irradiation apparatus 1B according to the present embodiment, the y electron beam e is applied by applying a triangular wave voltage to the coil 8b so that the amount of charge changes according to the change speed of the emission angle of the electron beam e. The electron beam e is swept so that the electron density is uniform in the sweep range.

  FIG. 16 is a graph showing an example of a voltage applied to an AC magnet in the X-ray irradiation apparatus 1B according to the third embodiment. As shown in FIG. 16, a triangular wave voltage is applied to the coil 8 b of the AC magnet 8 instead of a normal sine wave. Thereby, an electron beam e having a uniform electron density is obtained.

[Fourth Embodiment]
Hereinafter, the X-ray irradiation apparatus 1 according to the fourth embodiment will be described in detail with reference to the accompanying drawings. In the X-ray irradiation apparatus 1 according to the fourth embodiment, a heat conductive member 9 is provided on the target 5 in the X-ray irradiation apparatus 1 according to the first embodiment. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment thru | or 3rd Embodiment, and the overlapping description is abbreviate | omitted.

  FIG. 17A is a front view showing the configuration of the target 5 of the X-ray irradiation apparatus 1 according to the fourth embodiment, and FIG. 17B is the target of the X-ray irradiation apparatus 1 according to the fourth embodiment. 5 is an enlarged side view showing the configuration of FIG.

  As shown in FIG. 17A, a heat conducting member 9 is provided so as to surround a region of the target 5 where the electron beam e is irradiated. The heat conducting member 9 is made of Cu, Ag, Au, Al or the like having high heat conductivity. As shown in FIG. 17B, the heat conducting member 9 is formed integrally with the target 5 by being cast together with the target 5 so as to sandwich a part of the end portion of the target 5, for example. . Further, the heat conducting member 9 is thermally coupled to the external casing (in this embodiment, the low emittance accelerator 2b or the beam duct 2), thereby absorbing the heat generated in the target 5 and releasing it to the external casing. Therefore, the heat of the target 5 is suppressed.

  Thus, the X-ray irradiation apparatus 1 </ b> B according to the fourth embodiment can prevent the target 5 from being damaged by suppressing the heat of the target 5 from being increased by the heat conducting member 9.

[Fifth Embodiment]
Hereinafter, an X-ray irradiation apparatus 1C according to the fifth embodiment will be described in detail with reference to the accompanying drawings. 1C of X-ray irradiation apparatuses which concern on 5th Embodiment are the X-ray irradiation apparatuses 1 which concern on 1st Embodiment, instead of the shielding body 6 which has the single slit 6a, shield 6A which has several slit 6a. It is provided. In addition, the same code | symbol is attached | subjected to the structure same as 1st Embodiment thru | or 4th Embodiment, and the overlapping description is abbreviate | omitted.

  18A and 18B are schematic views showing a main part of an X-ray irradiation apparatus 1C according to the fifth embodiment. FIG. 18A is a schematic top view, and FIG. 18B is a schematic side view. As shown in FIGS. 18A and 18B, the X-ray beam X emitted from the target 5 is incident on the shield 6A downstream, and the X-ray beam X incident on the shield 6A is the shield. The tumor C is irradiated with a plurality of linear X-ray beams X which are narrowed down in the x direction by the plurality of slits 6 a and are transmitted through the shield 6.

  FIG. 19 is a perspective view showing a shield 6A of the X-ray irradiation apparatus 1C according to the fifth embodiment. As shown in FIG. 19, the shield 6A is composed of a plurality (six in this embodiment) of shielding units 6b made of heavy metal having excellent shielding ability against X-rays such as W. In the shield 6A, a plurality of slits 6a are formed by arranging the plurality of shielding units 6b so as to form gaps. Of the X-ray beam X incident on the shield 6, the X-ray beam X incident on the slit 6 a passes through the shield 6 and reaches the back of the shield 6, but the X-ray beam incident on the shield 6. Of the X, the X-ray beam X incident on the shielding unit 6b is shielded by the shielding unit 6b and thus does not reach the back of the shielding body 6.

  The shield 6 according to the present embodiment is configured by combining two substantially plate-shaped shield units 6b formed of heavy metal (W in the present embodiment) each having a high ability to shield the X-ray beam X. Yes.

  FIG. 20A is a schematic top view showing a main part of an X-ray irradiation apparatus 1C according to the fifth embodiment. As shown in FIG. 20A, each of the slits 6a of the shield 6A is provided at a different position so that the focal point of the X-ray beam X is located on the extended surface of the slit surface. Is formed in a fan shape as a whole. By providing the slit 6a in accordance with the radiation direction of the X-ray beam in this way, even if the X-ray beam X expands in a cone shape, a plate beam conversion efficiency equivalent to that of a parallel beam can be obtained.

  Further, as shown in FIGS. 19 and 20A, each slit 6a of the shield 6A emits an X-ray beam X from an entrance where the X-ray beam X is incident in the emission direction of the X-ray beam X. The slit 6a is formed so as to be wide toward the outlet (long in the short direction). As a result, even if a part of the X-ray beam X incident on the slit 6a deviates from the straight traveling direction at the time of incidence as it travels in the slit 6a, there is a high possibility that the deviated X-ray can also pass through the slit 6a. Therefore, as many X-rays as possible can be transmitted through the slit 6a.

  In the X-ray irradiation apparatus 1C according to the present embodiment, the example in which the plurality of slits 6a are gaps formed by the flat portions 6c of the adjacent shielding units 6b has been described, but the present invention is not limited thereto.

  In particular, in order to use an X-ray beam for radiation cancer treatment, a highly transmissive high-energy X-ray beam X is required, and even when a heavy metal such as tungsten is used to generate a plate beam for MRT. A shield having a thickness of about 10 cm is required. It is very difficult to manufacture a slit that passes through the thickness of the width of 100 μm or less. In order to solve this problem, it is preferable to use a manufacturing method in which a plurality of flat plates are combined as shown below.

  FIG. 20B is a schematic top view illustrating another example of the main part of the X-ray irradiation apparatus 1C according to the fifth embodiment. As shown in FIG. 20B, the shield 6A may be formed by combining a plurality of flat shield units 6d and flat auxiliary members 6e. The auxiliary member 6e is made of a material having a low shielding effect against X-rays, and the X-ray beam X incident on the region of the shielding body 6A where the auxiliary member 6e is provided is not shielded but is shielded by the shielding body 6A. Reach the back. Thereby, the shield 6A can be manufactured more easily.

  FIG. 21A is a graph showing the relationship between the position of the X-ray beam X transmitted through the shield 6A and the relative dose in the X-ray irradiation apparatus 1C according to the fifth embodiment, and FIG. In the X-ray irradiation apparatus 1C which concerns on 5th Embodiment, it is a figure which shows the shape of the X-ray beam X which permeate | transmitted the shield 6A.

  As shown in FIG. 21A, since only the X-ray beam X incident on the slit 6a is transmitted through the X-ray beam X incident on the shield 6A, a plurality of positions where the slit 6a is provided in the x-direction. As shown in FIG. 21B, a plurality of linear X-ray beams X substantially matching the shape of the entrance of the slit 6a are formed.

  FIG. 22 is a diagram illustrating an example of a beam profile of the X-ray beam X transmitted through the shield 6A in the X-ray irradiation apparatus 1C according to the fifth embodiment. As an example, as shown in FIG. 22, in a plurality of linear X-ray beams X after passing through the shield 6A, the width of each peak is 25 μm, the pitch between the peaks is 200 μm, and the minimum in the X-ray beam X The dose (the dose in the area shielded by the shield 6A) is 1% of the peak dose.

  In the X-ray irradiation apparatus 1C according to the present embodiment, the shielding unit 6d in the shielding body 6A is fixed. However, the present invention is not limited to this, and the dose of the X-ray beam X and the X-ray beam X to be finally generated are There may be provided adjusting means for adjusting the position of each shielding unit 6d in accordance with the shape. Thereby, the position of each slit 6a, the width | variety of the entrance part of the X-ray beam of each slit 6a, etc. are adjusted.

  Further, the position of the focal point of the X-ray beam X on the target 5 and the position of each shielding unit 6b may be adjusted so that the focal point of the X-ray beam X is positioned on the extension of each slit 6a. Thereby, the position of the focus of the X-ray beam X and the position of each slit 6a are adjusted.

  The flat X-ray beam necessary for MRT is generated by passing a thick X-ray beam through the slit of the shield. In order to efficiently generate a plate-shaped X-ray beam, multiple slits can be considered. A normal X-ray beam expands in a cone shape, but multiple slits are provided so that multiple slits are parallel to each other. However, since the slit located on the center side transmits X-rays, the slits located on both ends cannot transmit X-rays, so that the advantage of the multi-slit cannot be effectively utilized.

  In the X-ray irradiation apparatus 1 according to the present embodiment, the depth direction of the X-ray beam X of each slit 6a is determined according to the cone-shaped spread of the X-ray beam, so that only the slit 6a located at the center side can be used. Since the slits 6a located on both ends transmit X-rays, the advantage of the multi-slit can be effectively utilized.

  DESCRIPTION OF SYMBOLS 1, 1A thru | or 1C ... X-ray irradiation apparatus, 2 ... Beam duct, 2a ... Electron gun, 2b ... Low emittance accelerator, 3 ... Control apparatus, 4 ... Electron emission window, 5 ... Target, 6, 6A ... Shielding body, 6a ... Slit, 6b, 6d ... Shielding unit, 6c ... Plane, 6e ... Auxiliary member, 7 ... Deflecting magnet, 7a ... N magnet, 7b ... S magnet, 8 ... AC magnet, 8b ... Coil, 9 ... Heat conducting member, C ... Tumor, e ... Electron beam, X ... X-ray beam.

Claims (18)

A metal target that emits a braking X-ray as an X-ray beam when irradiated with an electron beam;
The metal target has a slit-shaped X-ray transmission part, and a part of the X-ray beam is transmitted through the X-ray transmission part and shields the X-ray beam incident on a region other than the X-ray transmission part. An X-ray shield disposed downstream of the X-ray beam in the emission direction;
An electron beam generator for irradiating the metal target with an electron beam having a diameter of a generation point of the emitted X-ray beam shorter than a length along a longitudinal direction of an entrance part of the X-ray transmission part;
An X-ray irradiation apparatus comprising: The shape of the electron beam emitted by the electron beam generator is controlled to be long in the direction along the longitudinal direction of the entrance portion of the X-ray transmission portion before being irradiated onto the metal target. The X-ray irradiation apparatus according to claim 1, further comprising a control unit that performs the control. Control means for controlling the irradiation position of the electron beam emitted from the electron beam generator to move in a direction corresponding to the longitudinal direction of the entrance portion of the X-ray transmission portion is further provided. The X-ray irradiation apparatus according to claim 1. The said control means is controlled so that the irradiation position to the said metal target of the said electron beam moves by changing the radiation | emission angle of the said electron beam radiate | emitted from the said electron beam generator. X-ray irradiation device. The X-ray irradiation apparatus according to claim 4, wherein when the emission angle of the electron beam is changed, the control unit controls the electron beam so that a charge amount changes according to the speed of the change. The X-ray irradiation apparatus according to any one of claims 1 to 5, wherein the metal target is formed to have a minimum thickness that does not damage the metal target when the electron beam is irradiated. . The thermal conduction member which was thermally coupled to the housing | casing or external housing | casing of the said electron beam generator, and was provided so that it might contact at least one part of the said metal target was further provided. X-ray irradiation device. The X-ray irradiation apparatus according to claim 7, wherein the heat conducting member is provided so as to surround a region of the metal target irradiated with the X-ray beam. The X-ray irradiating apparatus according to any one of claims 1 to 8, wherein the X-ray transmitting part has an inlet part with a width of 20 µm or more and 1 mm or less. The dose of the electron beam is such that the dose of the X-ray beam transmitted through the X-ray transmission part is 1 Gy or more and 1000 Gy or less, and is transmitted without being shielded by an area other than the X-ray transmission part of the X-ray shield. The dose of the said X-ray beam determined so that it may become 1/1000 or more and 1/10 or less of the dose of the said X-ray beam which permeate | transmitted the said X-ray permeation | transmission part. X-ray irradiation device. The X-ray beam emitted from the metal target is an X-ray beam expanding in a cone shape,
The X-ray shield is provided with a plurality of X-ray transmission portions at different positions so that the generation point of the X-ray beam is positioned on the extension in the depth direction of the X-ray transmission portion. The X-ray irradiation apparatus according to any one of 10. The X-ray irradiation apparatus according to claim 11, wherein the X-ray shield is formed by combining a plurality of flat shield members. 13. The X-ray irradiation apparatus according to claim 11, wherein each of the plurality of X-ray transmission portions is formed so as to gradually become wider toward an exit portion that is emitted from an entrance portion where the X-ray beam is incident. . The X-ray irradiation apparatus according to claim 11, further comprising a first adjustment unit that adjusts a width of an entrance portion of the plurality of X-ray transmission portions. 15. The apparatus according to claim 11, further comprising a second adjustment unit that adjusts a positional relationship between the generation point of the X-ray beam and the plurality of X-ray transmission parts of the X-ray shield. X-ray irradiation equipment. A plurality of shielding members each having a surface forming the X-ray transmission part between corresponding surfaces of adjacent shielding members are arranged on the X-ray transmission on the extension in the depth direction of each of the formed X-ray transmission parts. The X-ray irradiation apparatus according to claim 11, wherein the X-ray shields are arranged so that beam generation points are positioned. A metal target that emits braking X-rays as an X-ray beam when irradiated with an electron beam, and a beam diameter at the entrance of the X-ray beam incident on the downstream side of the metal target in the X-ray beam emission direction. An X-ray shield having a slit-shaped X-ray transmission part with a small width, and a part of the X-ray beam is transmitted through the X-ray transmission part and shields an X-ray beam incident on a region other than the X-ray transmission part When irradiating the metal target with the body and the electron beam, the target is irradiated with an electron beam whose diameter of the emitted X-ray beam is shorter than the length along the longitudinal direction of the entrance portion of the X-ray transmission portion. An X-ray irradiation method in an X-ray irradiation apparatus comprising:
A control step for controlling the shape of the electron beam emitted by the electron beam generator so as to be long in the direction along the longitudinal direction of the entrance portion of the X-ray transmission portion;
An emission step of emitting the X-ray beam by irradiating the metal target with the electron beam whose shape is controlled in the control step;
A transmission step of transmitting the X-ray beam emitted in the emission step through the X-ray transmission part;
An X-ray irradiation method comprising: A metal target that emits braking X-rays as an X-ray beam when irradiated with an electron beam, and a beam diameter at the entrance of the X-ray beam incident on the downstream side of the metal target in the X-ray beam emission direction. An X-ray shield having a slit-shaped X-ray transmission part with a small width, and a part of the X-ray beam is transmitted through the X-ray transmission part and shields an X-ray beam incident on a region other than the X-ray transmission part When irradiating the metal target with the body and the electron beam, the target is irradiated with an electron beam whose diameter of the emitted X-ray beam is shorter than the length along the longitudinal direction of the entrance portion of the X-ray transmission portion. An X-ray irradiation method in an X-ray irradiation apparatus comprising:
A control step of controlling the irradiation position of the electron beam emitted by the electron beam generator so as to move in a direction along the longitudinal direction of the entrance portion of the X-ray transmission portion;
An emission step of emitting the X-ray beam by irradiating the metal target with the electron beam controlled in the control step;
A transmission step of transmitting the X-ray beam emitted in the emission step through the X-ray transmission part;
An X-ray irradiation method comprising:

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