JP2017020813A - Charged particle beam irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charged particle beam irradiation device capable of improving economical efficiency while being small in size.SOLUTION: A charged particle beam irradiation device comprises: an accelerator for accelerating charged particle beams; a plurality of irradiation chambers in which the charged particle beams emitted from the accelerator are applied; and a beam transportation section having a plurality of deflection electromagnets and transporting the charged particle beams from the accelerator to the plurality of irradiation chambers through the plurality of deflection electromagnets. The beam transportation section comprises: a common beam transportation section annularly disposed along the accelerator in a plan view; and a plurality of branch beam transportation sections branching from the common beam transportation section at predetermined intervals and individually reaching the plurality of irradiation chambers. The plurality of irradiation chambers is annularly disposed along the accelerator in the plan view.SELECTED DRAWING: Figure 1

Description

  Embodiments according to the present invention relate to a charged particle beam irradiation apparatus.

  The charged particle beam irradiation apparatus accelerates the charged particle beam to high energy with an accelerator and irradiates the target with the accelerated charged particle beam. In order to efficiently use the charged particle beam, the charged particle beam irradiation apparatus may include a plurality of irradiation lines.

  As a representative charged particle beam irradiation apparatus including a plurality of irradiation lines, a particle beam therapy apparatus is known. The particle beam treatment apparatus treats a tumor by irradiating the tumor with a high-energy charged particle beam. The particle beam therapy system systematically distributes charged particle beams to a plurality of irradiation lines so that the standby time due to preparation work or the like occurring in each irradiation line does not affect the overall beam utilization efficiency.

  For example, in the conventional particle beam therapy system, the charged particle beam extracted from the accelerator may be branched to each of a plurality of irradiation chambers arranged side by side. However, in this case, there is a problem that the site area of the entire apparatus including the beam transport system becomes very large.

  Further, in the conventional particle beam therapy system, in order to save space, there are cases where the number of branching beam lines at each branching point is increased or beam lines are branched hierarchically. However, in these cases, because of the large number of beam line branches, it is difficult to find a solution for guiding the beam to the irradiation chamber in all the beam lines after the branch for the upstream beam conditions. It was. As a result, there is a problem that it is necessary to increase the number of electromagnets for adjusting the beam line.

JP 2000-75100 A

“MEDICAL HEAVY ION ACCELERATOR PROPOSALS” Trans. Nucl. Sci. Vol. NS-32 No.5 October 1985

  Provided is a charged particle beam irradiation apparatus which can be miniaturized and can be economically improved.

  The charged particle beam irradiation apparatus according to the present embodiment includes an accelerator that accelerates the charged particle beam, a plurality of irradiation chambers that irradiate the charged particle beam emitted from the accelerator, and a plurality of deflection electromagnets. A beam transport unit that transports a charged particle beam to the irradiation chamber, and the beam transport unit branches in a ring shape along the accelerator in plan view, and branches from the common beam transport unit at predetermined intervals And a plurality of branch beam transport sections that respectively reach the plurality of irradiation chambers, and the plurality of irradiation chambers are arranged in an annular shape along the accelerator in plan view.

  According to the present invention, it is possible to reduce the size and improve the economy.

It is a top view of the charged particle beam irradiation apparatus which shows 1st Embodiment. It is a top view of the charged particle beam irradiation apparatus which shows the modification of 1st Embodiment. It is a top view of the charged particle beam irradiation apparatus which shows 2nd Embodiment. It is a side view of the common beam transport part which shows a 3rd embodiment. It is a perspective view of the charged particle beam irradiation apparatus which shows 4th Embodiment. It is a side view of the beam transport part which shows the modification of 4th Embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings. This embodiment does not limit the present invention.

(First embodiment)
FIG. 1 is a schematic plan view of a charged particle beam irradiation apparatus 1 showing the first embodiment. The charged particle beam irradiation apparatus 1 can be used, for example, for particle beam therapy or elementary particle experiment.

  As shown in FIG. 1, the charged particle beam irradiation apparatus 1 includes a synchrotron accelerator 11, which is an example of an accelerator, a beam transport unit (beam transport system) 12, and a plurality of irradiation chambers 13. The synchrotron accelerator 11 accelerates the charged particle beam. The irradiation chamber 13 irradiates the charged particle beam emitted from the synchrotron accelerator 11. The beam transport unit 12 transports a charged particle beam from the synchrotron accelerator 11 to the irradiation chamber 13.

  The beam transport unit 12 includes a common beam transport unit 121 and a plurality of branch beam transport units 122. The common beam transport unit 121 is a component that ensures a common transport path of charged particle beams to the irradiation chambers 13. The common beam transport unit 121 includes a plurality of first deflection electromagnets B1. The branch beam transport unit 122 is a component that secures an individual transport path of the charged particle beam to each irradiation chamber 13. The branched beam transport unit 122 includes a second bending electromagnet B2.

  Further, the charged particle beam irradiation apparatus 1 includes a power source 14 for exciting the first deflecting electromagnet B1, a power source 15 for exciting the second deflecting electromagnet B2, and a control device 10 for controlling the amount of excitation of the power sources 14, 15. Is provided. The detailed configuration of the synchrotron accelerator 11 is not shown.

  As shown in FIG. 1, the common beam transport unit 121 is arranged in a substantially polygonal (substantially hexagonal in FIG. 1) ring surrounding the synchrotron accelerator 11. That is, the common beam transport unit 121 is arranged in a ring shape along the synchrotron accelerator 11 in a plan view. The site area of the charged particle beam irradiation apparatus 1 can be reduced by arranging the beam transport unit 12 in an annular shape.

  First bending electromagnets B <b> 1 are disposed at a plurality of corners of the common beam transport unit 121. Each first deflection electromagnet B1 is connected to a power source 14. The power source 14 is connected to the control device 10. The common beam transport unit 121 may further include a quadrupole electromagnet for beam transport adjustment and an electromagnet for trajectory correction.

  The plurality of branched beam transport sections 122 branch from the common beam transport section 121 in the circumferential direction Dc at predetermined intervals and reach the plurality of irradiation chambers 13 respectively. Specifically, as shown in FIG. 1, each branch beam transport unit 122 branches from each of a plurality of branch points P taken at predetermined intervals in the circumferential direction Dc on the common beam transport unit 121, It extends linearly to the irradiation chamber 13. Each branch point P exists between adjacent first deflection electromagnets B1, and a second deflection electromagnet B2 is disposed at each branch point P. Each branch beam transport part 122 is not branched downstream of the branch point P (on the irradiation chamber 13 side).

  More specifically, each branch beam transport section 122 is inclined at a predetermined acute angle θ with respect to the common beam transport section 121 outward in the radial direction Dr. By having an angle θ smaller than a right angle with respect to the common beam transport part 121, the downstream end of the branch beam transport part 122 is disposed at a position close to the common beam transport part 121. Thereby, the site area of the charged particle beam irradiation apparatus 1 can be further suppressed.

  A second deflection electromagnet B2 is disposed at each branch point P. Each second deflection electromagnet B2 is connected to a power source 15. The power supply 15 is connected to the control device 10. The branched beam transport unit 122 may include a quadrupole electromagnet.

  The plurality of irradiation chambers 13 are arranged at intervals in the circumferential direction Dc at the downstream end of each branch beam transport section 122. That is, each irradiation chamber 13 is arranged in a ring shape (radially) along the synchrotron accelerator 11 in a plan view. By arranging the irradiation chamber 13 in an annular shape, the site area of the charged particle beam irradiation apparatus 1 can be further reduced. In each irradiation chamber 13, irradiation equipment (not shown) is arranged.

  In the charged particle beam irradiation apparatus 1 according to the first embodiment having the above-described configuration, the charged particle beam generated by the beam source is incident on the synchrotron accelerator 11 via an incident device. The charged particle beam may be, for example, a proton or carbon ion beam. The synchrotron accelerator 11 deflects the incident charged particle beam with a plurality of deflecting electromagnets and circulates along the orbit. At this time, the synchrotron accelerator 11 circulates the charged particle beam stably with a quadrupole electromagnet while causing betatron oscillation in the horizontal direction and the vertical direction. The synchrotron accelerator 11 accelerates the circulating charged particle beam in the high-frequency acceleration cavity. And the synchrotron accelerator 11 is accelerated | stimulated to required energy, and is radiate | emitted to the beam transport part 12 side via the apparatus for extraction | emission.

  Next, the beam transport unit 12 transports the charged particle beam emitted from the synchrotron accelerator 11 to the irradiation chamber 13. At this time, the common beam transport unit 121 transports the charged particle beam to the downstream side along the annular transport path by the first deflection electromagnet B1. The branch beam transport unit 122 branches the charged particle beam from the common beam transport unit 121 to the irradiation chamber 13 side by the second deflection electromagnet B2.

  More specifically, the control device 10 controls the power supply 14 so as to supply an excitation current to each first deflection electromagnet B1. When the exciting current is supplied from the power supply 14, each first deflection electromagnet B1 is excited to apply an electromagnetic force to the charged particle beam. By applying an electromagnetic force from the first deflection electromagnet B1, the charged particle beam is deflected in the direction of the next first deflection electromagnet B1 on the downstream side. In addition, the control device 10 controls the power supply 15 so as to supply an excitation current to the second deflection electromagnet B2 corresponding to the irradiation chamber 13 to be irradiated with the charged particle beam. When the exciting current is supplied from the power supply 15, the second deflection electromagnet B2 is excited to apply an electromagnetic force to the charged particle beam. The charged particle beam is branched (deflected) in the direction of the irradiation chamber 13 by applying an electromagnetic force from the second deflection electromagnet B2.

  Next, in the irradiation chamber 13, the charged particle beam emitted from the synchrotron accelerator 11 and branched by the branch beam transport unit 122 is irradiated to the irradiation target through the irradiation device. The irradiation target is an affected part of a patient such as a tumor, for example.

  According to the first embodiment, an extra space between the synchrotron accelerator 11 and the irradiation chamber 13 is reduced by arranging the beam transport unit 12 and the irradiation chamber 13 in an annular shape so as to surround the synchrotron accelerator 11. it can. Since the extra space can be reduced, the site area of the entire charged particle beam irradiation apparatus 1 including the beam transport unit 12 can be suppressed. Further, according to the first embodiment, by providing the branch point P only on the common beam transport unit 121, the number of branches of the branch beam transport unit 122 can be suppressed. Since the number of branches can be reduced, the number of electromagnets for adjusting the beam line can be reduced, and the cost can be reduced. Therefore, according to the first embodiment, it is possible to reduce the size and improve the economy.

(Modification)
Next, as a modified example of the first embodiment, an example of the charged particle beam irradiation apparatus 1 that suppresses dispersion will be described. In addition, in this modification, about the structure part corresponding to FIG. 1, the overlapping description is abbreviate | omitted using the same code | symbol. FIG. 2 is a schematic plan view of the charged particle beam irradiation apparatus 1 showing a modification of the first embodiment.

  As shown in FIG. 2, the common beam transport unit 121 of the present modification further includes a first quadrupole electromagnet Q <b> 1 that suppresses the dispersion of the charged particle beam in addition to the configuration of the first embodiment. Dispersion is a deviation of particle trajectory or particle distribution depending on momentum.

  As shown in FIG. 2, the first quadrupole electromagnet Q <b> 1 is disposed at the corner of the common beam transport unit 121 so as to be sandwiched between the pair of first deflection electromagnets B <b> 1. The first quadrupole electromagnet Q1 is not limited to the arrangement of FIG. 2, for example, and is arranged in the vicinity of the downstream or upstream of the first deflection electromagnet B1 arranged in the corner of the common beam transport unit 121. Also good.

  The first quadrupole electromagnet Q1 is connected to a power source 16 for excitation. The power supply 16 is connected to the control device 10.

  In the charged particle beam irradiation apparatus 1 of the present modification having the above-described configuration, the control apparatus 10 controls the power supply 16 so as to supply an excitation current to the first quadrupole electromagnet Q1. When the exciting current is supplied from the power supply 16, the first quadrupole electromagnet Q1 is excited to apply an electromagnetic force to the charged particle beam. By applying an electromagnetic force from the first quadrupole electromagnet Q1, the charged particle beam is converged and dispersion is suppressed.

  Here, when deflected by the first deflecting electromagnet B1, the charged particle beam has a slightly different deflection trajectory depending on the momentum due to the momentum dispersion of the charged particle beam (that is, variation in the speed of each charged particle). Take. Specifically, a charged particle beam with a large momentum (that is, a high speed) passes through a deflection trajectory outside in the radial direction Dr than a charged particle beam with a small momentum (that is, a low speed). Dispersion occurs by taking different deflection trajectories according to the momentum. If the first deflection electromagnet B1 repeatedly deflects the beam in the same direction, the dispersion increases, and as a result, the beam size increases. As the beam size increases, the beam transport efficiency deteriorates.

  In contrast, the first quadrupole electromagnet Q1 can suppress dispersion by converging a charged particle beam having a different deflection trajectory in accordance with the momentum in the radial direction Dr.

  Therefore, according to the modification of the first embodiment, since the dispersion can be suppressed by the first quadrupole electromagnet Q1, the beam size can be reduced and the beam transport efficiency can be improved.

(Second Embodiment)
Next, as a second embodiment, an embodiment in which the deflection electromagnet of the branch beam transport unit 122 is shared with the deflection electromagnet of the common beam transport unit 121 will be described. In addition, in 2nd Embodiment, about the structure part corresponding to 1st Embodiment, the overlapping description is abbreviate | omitted using the same code | symbol. FIG. 3 is a plan view of the charged particle beam irradiation apparatus 1 showing the second embodiment.

  As shown in FIG. 3, the common beam transport unit 121 according to the second embodiment includes a third deflection electromagnet B3 instead of the first deflection electromagnet B1 and the second deflection electromagnet B2. Unlike the first deflection electromagnet B1 dedicated to the common beam transport section 121 and the second deflection electromagnet B2 dedicated to the branch beam transport section 122, the third deflection electromagnet B3 is different between the common beam transport section 121 and the branch beam transport section 122. This is a common (shared) deflection electromagnet.

  The third deflection electromagnet B3 is connected to an excitation power source 17. The power supply 17 is connected to the control device 10.

  In the charged particle beam irradiation apparatus 1 of the second embodiment having the above-described configuration, the control apparatus 10 transfers the charged particle beam to the irradiation chamber 13 at the branch point P and transports it downstream of the common beam transport unit 121. The amount of excitation (intensity) of the third deflection electromagnet B3 is different depending on the case. By varying the amount of excitation of the third deflection electromagnet B3, the charged particle beam can be distributed between the irradiation chamber 13 side and the common beam transport unit 121 side.

  According to the second embodiment, both the transport path of the common beam transport unit 121 and the transport path of the branch beam transport unit 122 can be secured by the third deflecting electromagnet B3, so that the number of deflecting electromagnets can be reduced. Since the number of deflection electromagnets can be reduced, the economy can be further improved.

(Third embodiment)
Next, as a third embodiment, an embodiment in which the phase difference of betatron oscillation between branch points is set to an integral multiple of π will be described. In addition, in 3rd Embodiment, about the structure part corresponding to 1st Embodiment, the overlapping description is abbreviate | omitted using the same code | symbol. FIG. 4 is a schematic side view of the common beam transport unit showing the third embodiment.

  As shown in FIG. 4, the common beam transport unit 121 according to the third embodiment is adjacent to the first branch point P <b> 1 where the first branch beam transport unit 122 branches and the first branch beam transport unit 122. Four second quadrupole electromagnets Q2_F1, D1, F2, and D2 that adjust the phase of the charged particle beam are provided between the second branch point P2 at which the matching second branch beam transport unit 122 branches. The first branch beam transport unit 122 is an arbitrary branch beam transport unit 122 among the plurality of branch beam transport units 122. The second branch beam transport unit 122 is, for example, the branch beam transport unit 122 adjacent to the first branch beam transport unit 122 on the downstream side.

  Here, Q2_F1 is a converging second quadrupole electromagnet arranged first from the first branch point P1. Q2_D1 is a second quadrupole electromagnet for divergence arranged second from the first branch point P1. Q2_F2 is a second quadrupole electromagnet for convergence arranged third from the first branch point P1. Q2_D2 is a second quadrupole electromagnet for diverging arranged fourth from the first branch point P1.

  When the distance between the first branch point P1 and Q2_F1 is La, the distance between Q2_F1 and Q2_D1 is Lb, and the distance between Q2_D2 and the second branch point P2 is Lc, the distance between Q2_D1 and Q2_F2 is Lc + La. The distance between Q2_F2 and Q2_D2 is Lb.

  Each of the second quadrupole electromagnets Q2_F1, D1, F2, and D2 is connected to a power source 18 for excitation. The power source 18 is connected to the control device 10.

  In the charged particle beam irradiation apparatus 1 according to the third embodiment having the above-described configuration, the control apparatus 10 turns on the power source 18 so as to excite Q2_F1 and Q2_F2 in the same direction (the direction in which the charged particle beam converges) and at the same intensity. Control. In addition, the control device 10 controls the power supply 18 so that Q2_D1 and Q2_D2 are excited in the opposite direction (the direction in which the charged particle beam diverges) and the same intensity as Q2_F1 and Q2_F2. Thereby, a π section is formed between the adjacent branch points P1 and P2, and the phase difference of the betatron oscillation between the adjacent branch points P1 and P2 can be set to π (180 °).

  When the phase difference is π, the Twiss parameter that defines the beam transport conditions at the branch points P1 and P2 can be matched at each of the branch points P1 and P2. By matching the Twiss parameter, beam adjustment on the downstream side of the beam line can be simplified.

  Note that the number and arrangement of the second quadrupole electromagnets are not limited to those shown in FIG. 4, and for example, five or more second quadrupole electromagnets may be provided. Further, in the second quadrupole electromagnet, the phase difference between the adjacent branch points P1 and P2 may be an integer multiple of 2 or more of π.

  Further, the control device 10 is configured to branch the charged particle beam to the irradiation chamber 13 at the branch point downstream of the second quadrupole electromagnets Q2_F1, D1, F2, and D2 and to branch to the downstream side of the common beam transport unit 121. The second quadrupole electromagnets Q2_F1, D1, F2, and D2 may be excited with different strengths. When the charged particle beam is branched to the irradiation chamber 13, the control device 10 may adjust the excitation amount of the second quadrupole electromagnets Q <b> 2 </ b> _F <b> 1, D <b> 1, F <b> 2, and D <b> 2 to satisfy the beam transport conditions to the irradiation chamber 13. Good. Here, in order to transport the charged particle beam to the irradiation chamber 13 under desired beam transport conditions, the branch beam transport unit 122 is usually provided with a plurality of quadrupole electromagnets for phase adjustment. On the other hand, if the amount of excitation of the second quadrupole electromagnets Q2_F1, D1, F2, and D2 is adjusted so as to satisfy the beam transport conditions to the irradiation chamber 13, the number of quadrupole electromagnets to be provided in the branch beam transport section 122 is reduced. Can be reduced. Economic efficiency can be further improved by reducing the number of quadrupole electromagnets.

  As described above, according to the third embodiment, by configuring the π section with the second quadrupole electromagnets Q2_F1, D1, F2, and D2, beam adjustment on the downstream side of the beam line can be simplified. Thereby, the number of elements (number of quadrupole electromagnets and the like) necessary for beam adjustment on the downstream side of the beam line can be reduced, so that the economic efficiency can be further improved.

(Fourth embodiment)
Next, an embodiment in which the synchrotron accelerator 11 and the irradiation chamber 13 are provided at different levels will be described as a fourth embodiment. Note that in the fourth embodiment, the description of the components corresponding to those of the second embodiment will be omitted by using the same reference numerals. FIG. 5 is a schematic perspective view of the charged particle beam irradiation apparatus 1 showing the fourth embodiment. In FIG. 5, the irradiation chamber 13 is not shown.

  In the first to third embodiments, it is assumed that the synchrotron accelerator 11 and the irradiation chamber 13 are installed in the same level of the building. That is, in the first to third embodiments, the synchrotron accelerator 11 and the irradiation chamber 13 are substantially in the same horizontal reference.

  On the other hand, in the fourth embodiment, the synchrotron accelerator 11 and the irradiation chamber 13 are installed at different levels of the building. In FIG. 5, the irradiation chamber 13 is installed on the upper floor from the synchrotron accelerator 11. Further, in order to install the synchrotron accelerator 11 and the irradiation chamber 13 at different levels, as shown in FIG.

  The charged particle beam irradiation apparatus 1 in FIG. 5 includes the third deflection electromagnet B3 as in the second embodiment, but includes the first and second deflection electromagnets B1 and B2 as in the first embodiment. May be. Further, the irradiation chamber 13 may be disposed inward in the radial direction Dr with respect to the common beam transporting part 121 in a layer different from the synchrotron accelerator 11.

  According to the fourth embodiment, by installing the irradiation chamber 13 at a different level from the synchrotron accelerator 11, a more compact configuration can be realized by effectively using the space.

(Modification)
Next, as a modification of the fourth embodiment, an example in which a charged particle beam is irradiated in the irradiation chamber 13 in a different layer from the second bending electromagnet B2 will be described. In addition, in this modification, about the structure part corresponding to FIG. 5, the overlapping description is abbreviate | omitted using the same code | symbol. FIG. 6 is a schematic side view of the beam transport unit 12 showing a modification of the fourth embodiment.

  As shown in FIG. 6, in this modification, each irradiation chamber 13 includes a first irradiation device 131 for horizontal irradiation and a second irradiation device 132 for vertical irradiation. As shown in FIG. 6, the charged particle beam irradiation apparatus 1 includes a fourth deflection electromagnet B4 for vertical irradiation.

  The first irradiation device 131 is connected to the second bending electromagnet B <b> 2 at the same level as the first irradiation device 131 through the duct D. The first irradiation device 131 may be the same as the irradiation device in the configurations of the first to third embodiments and FIG.

  The second irradiation device 132 on the upper floor u is connected to the second deflection electromagnet B2 on the lower floor via a duct D1 passing through the fourth deflection electromagnet B4. The second irradiation device 132 on the lower floor d is connected to the second deflection electromagnet B2 on the upper floor u via a duct D2 passing through the fourth deflection electromagnet B4. The fourth deflection electromagnet B4 is common to the ducts D1 and D2.

  The fourth deflection electromagnet B4 is connected to an excitation power source 19. The power source 19 is connected to the control device 10.

  In the charged particle beam irradiation apparatus 1 of the present modification having the above-described configuration, the control apparatus 10 includes a power supply 15 so as to excite the deflection electromagnets B2 and B4 corresponding to the irradiation chamber 13 and the irradiation devices 131 and 132 to be used. 19 is controlled.

  For example, when the first irradiation device 131 is to be used in the irradiation room 13 on the upper floor u, the control device 10 causes the charged particle beam to branch to the first irradiation device 131 side on the upper floor u. The second deflection electromagnet B2 is excited. Accordingly, the charged particle beam can be horizontally irradiated from the first irradiation device 131 in the irradiation chamber 13 on the upper floor u. Note that the irradiation direction of the first irradiation device 131 may be inclined with respect to the horizontal direction.

  When the second irradiation device 132 is to be used in the irradiation room 13 on the lower floor d, the control device 10 causes the second deflection electromagnet on the upper floor u to branch the charged particle beam toward the fourth deflection electromagnet B4. Energize B2. In addition, the control device 10 excites the fourth deflection electromagnet B4 so as to deflect the charged particle beam toward the second irradiation device 132 on the lower floor d. Thereby, the charged particle beam can be vertically irradiated from the second irradiation device 132 in the irradiation chamber 13 on the lower floor d. Note that the irradiation direction of the second irradiation device 132 may be inclined with respect to the vertical direction.

  On the other hand, when the second irradiation device 132 is to be used in the irradiation room 13 on the upper floor u, the control device 10 causes the second deflection electromagnet on the lower floor d to branch the charged particle beam toward the fourth deflection electromagnet B4. Energize B2. Further, the control device 10 excites the fourth deflection electromagnet B4 so as to deflect the charged particle beam toward the second irradiation device 132 on the upper floor u. Thereby, the charged particle beam can be vertically irradiated from the second irradiation device 132 in the irradiation chamber 13 on the upper floor u.

  According to the modification of the fourth embodiment, the degree of freedom in selecting the irradiation direction of the charged particle beam can be improved with a simple and small configuration. Further, since the fourth deflection electromagnet B4 can be used for both vertical irradiation on the upper floor and vertical irradiation on the lower floor, the number of parts can be suppressed.

  The first to fourth embodiments and the modification examples can be combined as appropriate. For example, the first quadrupole electromagnet Q1 described in the modification of the first embodiment may be applied to the second to fourth embodiments. Further, the third bending electromagnet B3 described in the second embodiment may be applied to the third embodiment.

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

DESCRIPTION OF SYMBOLS 1 Charged particle beam irradiation apparatus 11 Synchrotron accelerator 12 Beam transport part 121 Common beam transport part 122 Branch beam transport part 13 Irradiation chamber

Claims (8)

An accelerator to accelerate the charged particle beam;
A plurality of irradiation chambers for irradiating the charged particle beam emitted from the accelerator;
A plurality of deflection electromagnets, and a beam transport unit that transports the charged particle beam from the accelerator to the irradiation chamber with the deflection magnets,
The beam transport unit includes a common beam transport unit arranged in an annular shape along the accelerator in plan view, and a plurality of branch beams that branch from the common beam transport unit at predetermined intervals to reach the plurality of irradiation chambers, respectively. A transportation section,
The plurality of irradiation chambers are charged particle beam irradiation apparatuses arranged in a ring shape along the accelerator in a plan view.   The charged particle beam irradiation apparatus according to claim 1, wherein the deflecting electromagnet of the branch beam transport unit is made common with the deflecting electromagnet of the common beam transport unit.   The charged particle beam irradiation apparatus according to claim 1, wherein the common beam transport unit includes a first quadrupole electromagnet that suppresses dispersion of the charged particle beam. The common beam transport unit includes a first branch point where the first branch beam transport unit is branched, and a second branch beam transport unit adjacent to the first branch beam transport unit. And at least four second quadrupole electromagnets for adjusting the phase of the charged particle beam between the branch points;
The said 2nd quadrupole electromagnet adjusts the phase difference of the betatron oscillation of the said charged particle beam between the said 1st branch point and the said 2nd branch point to the integral multiple of (pi). The charged particle beam irradiation apparatus according to claim 1.   The second quadrupole electromagnet is excited with different intensities depending on whether the charged particle beam is branched to the irradiation chamber at the branch point downstream of the second quadrupole magnet or transported downstream of the common beam transport unit. The charged particle beam irradiation apparatus according to claim 4.   The charged particle beam irradiation apparatus according to claim 1, wherein the accelerator and the irradiation chamber are provided at different levels.   The charged particle beam irradiation apparatus according to claim 6, wherein the common beam transport unit is arranged in a spiral shape.   The charged particle beam irradiation apparatus according to claim 1, wherein the irradiation room is a treatment room.

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