JP6532008B2 - Phantom device for neutron beam measurement - Google Patents

Description

  The present invention relates to a phantom device for neutron beam measurement.

  Conventionally, the thing using a scintillator as what measures a neutron beam is described in patent document 1. FIG. On the other hand, as a monitor for particle beam such as X-ray, Patent Document 2 describes that a drive mechanism is provided in a case of a water phantom and a measurement unit is moved in the water phantom.

International Publication No. 2008/038662 Patent No. 5406142 gazette

  Here, when measuring a neutron beam, there existed a problem that it was difficult to apply the structure of a phantom apparatus like patent document 2. FIG. That is, since the neutron beam travels while diffusing in various directions, the driving mechanism for moving the measurement unit is irradiated with the neutron beam. Therefore, there is a problem that the measuring unit can not accurately measure the neutron beam due to the influence of the neutron beam reflected by the driving mechanism. In addition, there is a problem that it becomes difficult for the operator to approach due to the activation of the drive mechanism.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a phantom device for neutrons that can measure neutrons easily and accurately.

  The phantom device for neutron beam measurement according to the present invention can accommodate a human body simulation material to which neutron beams are irradiated, and has a housing portion having an opening at a position different from the upstream wall portion in the neutron beam irradiation direction. A detection unit that detects a neutron beam, a support unit that supports the detection unit in the storage unit and extends outward from the storage unit through the opening, and a drive unit that applies a driving force to the support unit, The driving portion is provided outside the housing portion and at a position separated from the housing portion.

  The phantom device for neutron beam measurement according to the present invention comprises a support unit for supporting the detection unit in the storage unit, and a drive unit for applying a driving force to the support unit. Therefore, the detection unit can detect the neutron beam at a plurality of positions of the accommodation unit by moving in the accommodation unit by the driving force applied via the support unit. Here, the support portion extends outward from the storage portion through the opening portion of the storage portion, and the drive portion is provided at a position outside the storage portion and away from the storage portion. With such a configuration, the drive unit can apply a driving force to the detection unit via the support unit from a position separated from the storage unit. Thus, by arranging the drive unit at a position separated from the storage unit, it is possible to suppress the neutron beam irradiated and diffused to the human body simulating substance in the storage unit from colliding against the drive unit and being reflected. Therefore, it can suppress that a detection part misdetects the neutron beam reflected by the drive part. In addition, since the activation of the drive unit can be suppressed due to the collision of the neutron beam, the handleability for the worker is improved. By the above, a neutron beam can be measured easily and precisely.

  In the phantom device for neutron beam measurement according to the present invention, the drive unit may be provided to be separated from the housing portion toward the downstream side in the irradiation direction of the neutron beam. With such a configuration, it is possible to suppress the diffused neutron beam from colliding with the drive part as compared with the case where the drive part is separated in the other direction.

  In the phantom device for neutron beam measurement according to the present invention, the support portion is bent from the first member extending from the detection portion to the outside of the housing through the opening and from the first member outside the housing. And a second member extending toward the drive unit. With such a configuration, the support portion can transmit the driving force from the drive portion to the detection portion in a state of being largely retracted from the inside of the housing portion. By this, in a state where the drive unit is sufficiently separated from the housing unit, the support unit can transmit the driving force to the detection unit without interfering with the housing unit.

  In the phantom device for neutron beam measurement according to the present invention, at least a part of the support portion on the detection portion side may be made of an equivalent substance equivalent to a human body mimic substance. With such a configuration, it is possible to suppress the neutron beam from being reflected by the support portion in the vicinity of the detection portion, so that the detection accuracy of the detection portion can be improved.

  According to the present invention, it is possible to measure neutrons easily and accurately.

It is the schematic which shows the structure of the neutron capture therapy apparatus which irradiates the neutron beam used as the measurement object of the phantom apparatus for neutron beam measurement which concerns on embodiment of this invention. It is a perspective view of a phantom device for neutron beam measurement concerning an embodiment of the present invention. It is a perspective view of a phantom device for neutron beam measurement concerning an embodiment of the present invention. It is a perspective view of a phantom device concerning a comparative example.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description.

First, an example of the configuration of the neutron capture therapy apparatus 1 for irradiating the neutron beam N, which is a measurement target of the phantom device 100 for neutron beam measurement according to the present embodiment, will be described. A neutron capture therapy apparatus 1 shown in FIG. 1 is an apparatus for performing cancer treatment using boron neutron capture therapy (BNCT). In the neutron capture therapy apparatus 1, for example, a tumor of a patient (irradiated body) 50 to which boron ( ¹⁰ B) is administered is irradiated with a neutron beam N.

  The neutron capture therapy apparatus 1 includes a cyclotron 2. The cyclotron 2 is an accelerator that accelerates charged particles such as negative ions to create a charged particle beam R. In the present embodiment, the charged particle beam R is a proton beam generated by stripping charges from anions. The proton beam is generated by stripping the electrons of the accelerated negative ions in the cyclotron 2 using a foil stripper or the like, and is emitted from the cyclotron 2. The cyclotron 2 has, for example, the ability to generate a charged particle beam R having a beam radius of 40 mm and 60 kW (= 30 MeV × 2 mA). The accelerator is not limited to a cyclotron, and may be a synchrotron, a synchro cyclotron, a linac, or the like.

  The charged particle beam R emitted from the cyclotron 2 is sent to the neutron beam generation unit M. The neutron beam generation unit M includes a target 7, a moderator 9, and a collimator 10. The charged particle beam R emitted from the cyclotron 2 travels through the beam duct 3 toward the target 7 disposed at the end of the beam duct 3. Along the beam duct 3, a plurality of quadrupole magnets 4, a current detection unit 5, and a scanning electromagnet 6 are provided. The plurality of quadrupole electromagnets 4 perform beam axis adjustment and beam diameter adjustment of the charged particle beam R using, for example, an electromagnet.

  The current detection unit 5 detects the current value (that is, the charge, irradiation dose rate) of the charged particle beam R irradiated to the target 7 in real time during irradiation of the charged particle beam R. The current detection unit 5 uses a nondestructive DCCT (DC Current Transformer) that can measure current without affecting the charged particle beam R. That is, the current detection unit 5 can measure the current value of the charged particle beam R without touching (without contacting) the charged particle R. The current detection unit 5 outputs the detection result to a control unit (not shown). In addition, a "dose rate" means the dose per unit time.

  Specifically, in order to accurately detect the current value of the charged particle beam R irradiated to the target 7, the current detection unit 5 downstream of the quadrupole electromagnet 4 in order to accurately detect the current value of the charged particle beam R (charged particles It is provided immediately before the scanning electromagnet 6 at the downstream side of the line R). That is, since the scanning electromagnet 6 scans the target 7 so that the charged particle beam R is not always irradiated to the same place, a large current detection is required to arrange the current detection unit 5 downstream of the scanning electromagnet 6 Part 5 is required. On the other hand, by providing the current detection unit 5 on the upstream side of the scanning electromagnet 6, the current detection unit 5 can be miniaturized.

  The scanning electromagnet 6 scans the charged particle beam R and controls irradiation of the charged particle beam R to the target 7. The scanning electromagnet 6 controls the irradiation position of the charged particle beam R on the target 7.

  The neutron capture therapy apparatus 1 generates the neutron beam N by irradiating the charged particle beam R to the target 7 and emits the neutron beam N toward the patient 50. The neutron capture therapy apparatus 1 includes a target 7, a shield 8, a moderator 9, a collimator 10, and a gamma ray detection unit 11.

  The target 7 is irradiated with the charged particle beam R to generate a neutron beam N. The target 7 here is formed of, for example, beryllium (Be), lithium (Li), tantalum (Ta), or tungsten (W), and has a disk shape having a diameter of 160 mm, for example. In addition, the target 7 is not limited to plate shape, For example, a liquid may be sufficient.

  The moderator 9 decelerates the neutron beam N generated by the target 7 to reduce the energy of the neutron beam N. Moderator 9 comprises a first moderator 9A for mainly decelerating fast neutrons contained in neutron beam N, and a second moderator 9B for mainly decelerating epithermal neutrons contained in neutron beam N. It has a laminated structure.

  When the shielding body 8 decelerates the generated neutron beam N, secondary radiation such as a gamma ray generated at the target 7 with the generation of the neutron beam N, and the neutron beam N by the moderator 9 And shields secondary radiation such as gamma rays generated by the moderator 9 to suppress the radiation from being emitted to the irradiation room where the patient 50 is present. The shield 8 is provided to surround the moderator 9. The upper part and the lower part of the shield 8 extend on the upstream side of the charged particle beam R from the moderator 9, and the gamma ray detection unit 11 is provided in these extended parts.

  The collimator 10 shapes the irradiation field of the neutron beam N, and has an opening 10 a through which the neutron beam N passes. The collimator 10 is, for example, a block-like member having an opening 10 a at the center.

  The gamma ray detection unit 11 detects a gamma ray generated from the neutron beam generation unit M by the irradiation of the charged particle beam R in real time during the generation of a neutron beam (that is, during the irradiation of the neutron beam N to the patient 50). As the gamma ray detection unit 11, a scintillator, an ionization chamber, and various other gamma ray detection devices can be employed. In the present embodiment, the gamma ray detection unit 11 is provided on the upstream side of the charged particle beam R from the moderator 9 around the target 7.

  The gamma ray detection unit 11 is disposed inside the upper portion and the lower portion of the shield 8 extending to the upstream side of the charged particle beam R. The number of gamma ray detectors 11 is not particularly limited, and may be one or three or more. When three or more gamma ray detectors 11 are provided, they can be provided at predetermined intervals so as to surround the outer periphery of the target 7. The gamma ray detection unit 11 outputs the detection result of the gamma ray to a control unit (not shown). The gamma ray detection unit 11 may not be provided.

  Next, with reference to FIG. 2 and FIG. 3, the configuration of the phantom device 100 for neutron beam measurement according to the present embodiment will be described. The phantom device 100 for neutron beam measurement measures the beam profile of the neutron beam N irradiated from the neutron capture therapy device 1 before actual treatment for guaranteeing treatment quality before treatment. The neutron beam measurement phantom device 100 includes a housing portion 20, a detection portion 21, a support portion 22, a drive portion 23, and a pedestal 24. For convenience of explanation, an XYZ coordinate system is shown in FIGS. 2 and 3. The Y-axis direction is the direction in which the neutron beam N is irradiated. Here, the Y axis direction positive side is the downstream side in the irradiation direction of the neutron beam N, and the Y axis direction negative side is the upstream side in the irradiation direction of the neutron beam N. In the present embodiment, the Y-axis direction (i.e., the irradiation direction of the neutron beam N) is horizontal. The X-axis direction is a horizontal direction orthogonal to the Y-axis direction. The Z-axis direction is a direction orthogonal to the X-axis direction and the Y-axis direction, that is, the vertical direction. The positive side in the Z-axis direction is the upper side, and the negative side in the Z-axis direction is the lower side.

  The accommodation unit 20 is a container capable of accommodating a human body simulation substance to which the neutron beam N is irradiated. The human body simulating substance is a substance to be a model imitating the human body when measuring the beam profile of the neutron beam N. In the present embodiment, water W is adopted as a human body mimic substance. The housing unit 20 only needs to contain a human body simulating substance when measuring at least the neutron beam N, and when transporting the phantom device 100 for neutron beam measurement, the housing unit 20 does not contain a human body simulating substance. It is good.

  The housing portion 20 has a rectangular box shape, and includes a bottom wall portion 20a, side walls 20b and 20c opposite in the Y-axis direction, and side walls 20d and 20e opposite in the X-axis direction. The side wall portion 20 b disposed on the Y axis direction negative side is an upstream side wall portion in the irradiation direction of the neutron beam N. The side wall portion 20 c disposed on the Y axis direction positive side is a wall portion on the downstream side in the irradiation direction of the neutron beam N. The upper wall portion is not provided at the upper end portion (a position different from the upstream side wall portion in the irradiation direction of the neutron beam N) of the housing portion 20, and an opening 20f is formed. In addition, an upper wall part may be provided in the accommodating part 20, and an opening part may be formed in the area | region of a part of the said upper wall part. When the neutron beam N is measured by the neutron beam measurement phantom device 100, the neutron beam measurement phantom device 100 is disposed such that the side wall 20b of the housing portion 20 faces the opening 10a of the collimator 10 (FIG. 1) reference). Therefore, the neutron beam N which passed the opening 10a is irradiated to the water W in the accommodating part 20 via the side wall part 20b.

  The detection unit 21 detects the neutron beam N irradiated to the water W. The detection unit 21 is disposed in the water W during measurement of the neutron beam N. Here, the neutron beam N travels to diffuse in the water W. The detection unit 21 moves in the water W by the driving force from the drive unit 23. By this, the detection unit 21 can detect the neutron beam N at each location in the water W. The detection unit 21 can detect the dose of the neutron beam N at the arrangement location.

  For example, a scintillation detector may be employed as the detection unit 21. When a scintillation detector is employed as the detection unit 21, the scintillator 26 is disposed in the water W. The scintillator 26 is a phosphor that converts the incident neutron beam N into light. The scintillator 26 excites the internal crystal according to the dose of the incident neutron beam N, and generates scintillation light. The scintillator light is transmitted to an operation unit (not shown) by an optical fiber (not shown). The calculation unit calculates the dose of the neutron beam N based on the light transmitted by the optical fiber. In addition to the scintillation detector, an ion chamber, a gas chamber, a semiconductor detector, a proportional coefficient tube, or the like may be employed as the detection unit 21.

  The support portion 22 supports the detection portion 21 in the housing portion 20. The support portion 22 is connected to the detection portion 21 at one end side, and is connected to the drive portion 23 at the other end side. By this, the support part 22 moves with the detection part 21 by the driving force from the drive part 23. The support portion 22 is a first member 22a extending from the detection portion 21 to the outside of the housing portion 20 through the opening 20f, and bent from the first member 22a outside the housing portion 20 toward the drive portion 23 And a second member 22b that extends. The support portion 22 has a substantially L-shaped shape as a whole.

  The first member 22a extends in the vertical direction (Z-axis direction), the detection unit 21 is fixed to the lower end, and the second member 22b is fixed to the upper end. At least during measurement of the neutron beam N, the lower end portion of the first member 22a is disposed in the housing portion 20 together with the detection portion 21, and the upper end portion of the first member 22a is the upper end portion of the housing portion 20 (that is, the opening 20f). It is arranged above). The second member 22 b extends from the upper end of the first member 22 a toward the drive unit 23, and is fixed to the drive 23 at the end opposite to the first member 22 a. As described later, in the present embodiment, the drive unit 23 is disposed on the Y axis direction positive side, that is, on the downstream side in the irradiation direction of the neutron beam N with respect to the housing unit 20. Therefore, the second member 22 b extends from the upper end of the first member 22 a toward the Y axis direction positive side, that is, toward the downstream side in the irradiation direction of the neutron beam N. At least a part of the support portion 22 on the side of the detection portion 21 is made of an equivalent substance equivalent to a human body mimic substance (water W in the present embodiment). In the present embodiment, the first member 22a and the second member 22b are made of acrylic equivalent to water. In addition, the part arrange | positioned at least in the accommodating part 20 among the support parts 22 should just be comprised with an equivalent substance. For example, the first member 22a housed in the housing portion 20 may be made of an equivalent substance, and the second member 22b disposed at a position separated from the housing portion 20 may not be made of an equivalent substance.

  The pedestal 24 is a member for supporting the housing portion 20 and the drive portion 23, and has a first rectangular pedestal 28 for supporting the housing portion 20 and a rectangular plate for supporting the drive portion 23. And the second pedestal 29 of the In the present embodiment, the second pedestal 29 is disposed on the downstream side (that is, the Y axis direction positive side) in the irradiation direction of the neutron beam N with respect to the first pedestal 28. The lower surface of the edge on the Y axis direction positive side of the first pedestal 28 is connected to the upper surface of the edge on the Y axis direction negative side of the second pedestal 29. In the step between the edge of the first pedestal 28 on the Y axis direction positive side and the edge of the second pedestal 29 on the Y axis direction negative side, a rail portion 31 extending in the X axis direction is provided. Provided.

  The drive unit 23 applies a driving force to the support unit 22 to move the detection unit 21 in the housing unit 20. The driving unit 23 may apply a driving force in at least one axial direction, but in the present embodiment, the driving force can be applied in three axial directions. Therefore, the drive unit 23 can move the detection unit 21 three-dimensionally in the housing unit 20. Specifically, the drive unit 23 includes an X-axis actuator 32, a Y-axis actuator 33, and a Z-axis actuator 34 to drive the detection unit 21 and the support unit 22 in the XYZ axial directions. It can be granted. In addition, each actuator 32, 33, 34 of the drive part 23 may be comprised with a metal material.

  The X-axis actuator 32 includes an X-axis rail portion 32A extending in the X-axis direction, an X-axis movable portion 32B reciprocating in the X-axis direction along the upper surface of the X-axis rail portion 32A, and a driving force of the X-axis movable portion 32B. And an X-axis driving force generating unit 32C that generates the In the present embodiment, the X-axis actuator 32 is disposed at the edge of the second pedestal 29 on the Y axis direction positive side. A mounting member 36 extending in the Y-axis direction is provided on the X-axis movable portion 32B. An end on the Y axis direction negative side of the placement member 36 is movably connected to the rail portion 31, and an end on the Y axis direction positive side is connected to the upper surface of the X axis movable portion 32B. Thus, the placement member 36 moves in the X-axis direction in accordance with the movement of the X-axis movable portion 32B.

  The Y-axis actuator 33 comprises a Y-axis rail portion 33A extending in the Y-axis direction, a Y-axis movable portion 33B reciprocating in the Y-axis direction along the upper surface of the Y-axis rail portion 33A, and a driving force of the Y-axis movable portion 33B. And a Y-axis driving force generating unit 33C that generates the In the present embodiment, the Y-axis actuator 33 is disposed on the mounting member 36. A mounting member 37 wider than the Y-axis movable portion 33B is provided on the Y-axis movable portion 33B. The placement member 37 moves in the Y-axis direction in accordance with the movement of the Y-axis movable portion 33B.

  The Z-axis actuator 34 generates a driving force of a Z-axis rail portion 34A extending in the Z-axis direction, a Z-axis movable portion 34B reciprocating in the Z-axis direction along the Z-axis rail portion 34A, and a Z-axis movable portion 34B. And a Z-axis driving force generating unit 34C. The Z-axis movable portion 34B reciprocates in the Z-axis direction along the side surface on the Y-axis direction negative side of the Z-axis rail portion 34A. In the present embodiment, the Z-axis actuator 34 is disposed on the mounting member 37. An end of the second member 22b of the support portion 22 on the Y axis direction positive side is fixed to the Z-axis movable portion 34B via the fixing member 38.

  The driving unit 23 is provided to be separated from the housing unit 20 toward the downstream side in the irradiation direction of the neutron beam N. The actuators 32, 33, 34 of the drive unit 23 are disposed at a position on the Y axis direction positive side at least with respect to the side wall 20 c of the accommodation unit 20. Further, a portion of the drive portion 23 which is disposed at the most negative position in the Y-axis direction (in the present embodiment, the end on the Y-axis direction negative side of the Y-axis rail 33A of the Y-axis actuator 33 or the Z axis actuator The surface on the Y axis direction negative side of the Z axis movable portion 34B of 34 is also separated from the accommodation portion 20 to the Y axis direction positive side.

  Next, the operation and effect of the phantom device 100 for neutron beam measurement according to the present embodiment will be described.

  First, the measurement method according to the comparative example will be described. In the measurement method according to the comparative example, a step of attaching gold foil to a plurality of fixing jigs, a step of fixing a plurality of fixing jigs to which the gold foil is attached to a containing portion containing water, and the containing portion And the step of irradiating the neutron beam N with the neutron capture therapy apparatus, and the step of removing the activated gold foil from the fixing jig of the container and performing the activation analysis. According to such a measurement method, in addition to the radiation time of the neutron beam, activation analysis needs to be performed for the number of measurement points, so that the time for measurement becomes long and the measurement operation is complicated. There was a problem.

  On the other hand, a phantom device 200 as shown in FIG. 4 is used for measurement of a proton beam or a particle beam. The phantom device 200 shown in FIG. 4 includes a drive unit 203 that applies a driving force to the detection unit 202 disposed in the storage unit 201 in which the water W is stored. The phantom device 200 can perform measurement in a short time as compared with the above-described measurement method by moving the detection unit 202 in the storage unit 201 by the driving force of the drive unit 203 and performing measurement at a plurality of locations. . However, in such a phantom device 200, the drive unit 203 is directly provided in the housing unit 201. That is, the actuators of the drive unit are provided at the upper edge portion of the accommodation unit 201 and inside the accommodation unit 201. When the neutron beam N is measured by the phantom device 200 provided at a position where each actuator of the drive unit 203 is in proximity to the accommodation unit 201 as described above, the following problem occurs. That is, since the neutron beam N is not irradiated in a narrow range like a proton beam or a particle beam but irradiated in a wide range, neutrons reflected by the actuator of the drive unit 203 are reflected. The influence of the line N causes a problem that the detection unit 202 can not accurately measure the neutron beam N. In addition, the actuator of the drive unit 203 becomes radioactive, which causes a problem that it is difficult for the operator to approach.

  On the other hand, the neutron beam measurement phantom device 100 according to the present embodiment includes a support 22 that supports the detection unit 21 in the housing 20, and a drive 23 that applies a driving force to the support 22. Therefore, the detection unit 21 can detect the neutron beam N at a plurality of positions of the housing unit 20 by moving in the housing unit 20 by the driving force applied via the support unit 22. Therefore, as compared with the above-mentioned measurement method using gold foil, the time required for measurement of the neutron beam N can be significantly shortened.

  Here, the support portion 22 extends outward from the accommodation portion 20 upward through the opening 20 f of the accommodation portion 20. In addition, the drive unit 23 is provided outside the housing unit 20 and at a position separated from the housing unit 20. With such a configuration, the drive unit 23 can apply a driving force to the detection unit 21 via the support unit 22 from a position separated from the housing unit 20. Thus, by arranging the drive unit 23 at a position separated from the storage unit 20, the neutron beam N irradiated and diffused to the water W in the storage unit 20 collides with the drive unit 23 and is reflected. It can be suppressed. Therefore, it can suppress that the detection part 21 misdetects the neutron beam N reflected in the drive part 23. FIG. In addition, since the activation of the drive unit 23 can be suppressed due to the collision of the neutron beam N, the handleability for the operator is improved. By the above, the neutron beam N can be measured easily and accurately.

  In the phantom device 100 for neutron beam measurement according to the present embodiment, the drive unit 23 is provided to be separated from the housing unit 20 toward the downstream side in the irradiation direction of the neutron beam N. With such a configuration, diffusion is made in comparison with the case where the drive unit 23 is separated in the other direction (for example, in the direction orthogonal to the irradiation direction, such as the position facing the side wall 20 d or the position facing the side wall 20 e) The collision of the neutron beam N with the drive unit 23 can be suppressed.

  In the phantom device 100 for neutron beam measurement according to the present embodiment, the support 22 is a first member 22 a that extends from the detection unit 21 to the outside of the housing 20 via the opening 20 f and the outside of the housing 20. And a second member 22b bent and extended from the first member 22a to the drive unit 23 side. With such a configuration, the support portion 22 can transmit the driving force from the drive portion 23 to the detection portion 21 in a state of being largely retracted from the inside of the housing portion 20. Thus, in a state where the drive unit 23 is sufficiently separated from the housing unit 20, the support unit 22 can transmit the driving force to the detection unit 21 without interference with the housing unit 20.

  In the phantom device 100 for neutron beam measurement according to the present embodiment, at least a part of the support portion 22 on the side of the detection portion 21 is made of an equivalent substance equivalent to water W. With such a configuration, it is possible to suppress the neutron beam N from being reflected by the support portion 22 in the vicinity of the detection portion 21, so that the detection accuracy of the detection portion 21 can be improved.

  The present invention is not limited to the embodiments described above.

  For example, the phantom device for neutron beam measurement according to the above-described embodiment has one detection unit for detecting the neutron beam N. However, the number of detection units is not particularly limited, and a plurality of detection units may be provided. For example, a plurality of detection units may be provided at different positions in the X-axis direction. In addition, a plurality of detection units may be provided at different positions in the Y-axis direction. In addition, a plurality of detection units may be provided at different positions in the Z-axis direction.

  Moreover, the drive part of the phantom device for neutron beam measurement concerning the above-mentioned embodiment was spaced apart and provided from the accommodation part toward the lower stream side of the irradiation direction of neutron beam N. Instead of this, the drive unit may be provided in a direction perpendicular to the irradiation direction of the neutron beam N and separated from the housing unit. For example, the drive unit may be provided on the X axis direction positive side (a position facing away from the side wall portion 20e) with respect to the housing portion, and the X axis direction negative side (spaced from the side wall portion 20d) (Oppositely facing each other). When the installation space of the drive unit can be secured, the drive unit may be provided on the Z axis direction positive side (a position facing away from the opening 20f) with respect to the storage unit, and It may be provided on the axial negative side (a position facing away from the side wall 20d). Further, even when the drive unit is provided to be separated from the housing unit toward the downstream side of the irradiation direction of the neutron beam N, a part of the drive unit is orthogonal to the irradiation direction of the neutron beam N It may extend in a direction away from the receptacle.

  Further, in the drive unit of the phantom device for neutron beam measurement according to the above-described embodiment, the X-axis actuator 32 supports the Y-axis actuator 33, and the Y-axis actuator 33 supports the Z-axis actuator 34. However, the combination of the respective actuators is not particularly limited. For example, the Y-axis actuator 33 may support the X-axis actuator 32, and the X-axis actuator 32 may support the Z-axis actuator 34. Alternatively, the X-axis actuator 32 may support the Z-axis actuator 34, and the Z-axis actuator 34 may support the Y-axis actuator 33. Also, the Z-axis actuator 34 may support the X-axis actuator 32, and the X-axis actuator 32 may support the Y-axis actuator 33. Alternatively, the Y-axis actuator 33 may support the Z-axis actuator 34, and the Z-axis actuator 34 may support the X-axis actuator 32. Alternatively, the Z-axis actuator 34 may support the Y-axis actuator 33, and the Y-axis actuator 33 may support the X-axis actuator 32.

  In addition, although the drive part of the phantom device for neutron beam measurement concerning the above-mentioned embodiment was a structure which can give driving force to 3 axial directions by linear motion, driving force is given to 2 axial directions or 1 axial direction. The structure may be The direction in which the drive unit can not apply the driving force may be coped with by providing a plurality of detection units. For example, when the drive unit can apply the driving force only in the X-axis direction and the Y-axis direction, detection units may be provided at a plurality of locations in the Z-axis direction. Furthermore, in addition to or instead of the linear motion actuator, a rotational motion actuator may be provided.

  DESCRIPTION OF SYMBOLS 1 ... Neutron capture therapy apparatus, 21 ... Detection part, 22 ... Support part, 22a ... 1st member, 22b ... 2nd member, 23 ... Drive part, 100 ... Phantom apparatus for neutron beam measurement.

Claims (4)

A housing portion capable of housing a human body simulation material to which neutron beams are irradiated, and having an opening at a position different from the upstream wall portion in the irradiation direction of the neutron beams;
A detection unit that detects the neutron beam;
A support portion that supports the detection portion in the storage portion and extends outward from the storage portion via the opening;
And a drive unit for applying a driving force to the support unit,
The drive unit moves the detection unit in a plurality of directions via the support unit without moving the storage unit, and includes an individual actuator corresponding to each of the plurality of directions.
A phantom for neutron beam measurement , wherein all the individual actuators are provided outside of the housing and not overlapping the opening when viewed from the direction separated from the housing and orthogonal to the opening apparatus.   2. The phantom device for neutron beam measurement according to claim 1, wherein the drive unit is provided to be separated from the accommodation unit toward the downstream side in the irradiation direction of the neutron beam.   The support portion is a first member extending from the detection portion to the outside of the storage portion via the opening, and bent from the first member outside the storage portion and extending to the drive portion side The phantom device for neutron beam measurement according to claim 1 or 2, further comprising:   The phantom for neutron beam measurement according to any one of claims 1 to 3, wherein at least a part of the support portion on the side of the detection portion is made of an equivalent substance equivalent to the human body mimic substance. apparatus.

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