JP2013096949A - Scanning type electromagnet and charged particle beam irradiation device - Google Patents

Scanning type electromagnet and charged particle beam irradiation device Download PDF

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JP2013096949A
JP2013096949A JP2011242476A JP2011242476A JP2013096949A JP 2013096949 A JP2013096949 A JP 2013096949A JP 2011242476 A JP2011242476 A JP 2011242476A JP 2011242476 A JP2011242476 A JP 2011242476A JP 2013096949 A JP2013096949 A JP 2013096949A
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direction magnetic
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Takamichi Aoki
孝道 青木
Masumi Umezawa
真澄 梅澤
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Hitachi Ltd
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PROBLEM TO BE SOLVED: To secure a beam scanning range by taking a uniform magnetic field area as wide in a dual window frame type electromagnet.SOLUTION: Coils 101, 108, 111, 118 are arranged between a first sub area passing through Y direction magnetic field excitation current and a second sub area passing through the Y direction magnetic field excitation current, constituting a first sub area passing through X direction magnetic field excitation current; coils 109, 110, 119, 120 are arranged between main areas 221, 222 passing through the Y direction magnetic field excitation current and the first sub area passing through the Y direction magnetic field excitation current, constituting a second sub area passing through the X direction magnetic field excitation current; coils 201, 208, 211, 218 are arranged between the first sub area passing through the X direction magnetic field excitation current and a second sub area passing through the X direction magnetic field excitation current, constituting the first sub area passing through the Y direction magnetic field excitation current; and coils 209, 210, 219, 220 are arranged between main areas 121, 122 passing through the X direction magnetic field excitation current and the first sub area passing through the X direction magnetic field excitation current, constituting the second sub area passing through the Y direction magnetic field excitation current.

Description

本発明は、1つの電磁石でX方向・Y方向に励磁できる二重窓枠型電磁石およびこの走査電磁石を備える荷電粒子ビーム照射装置に関する。   The present invention relates to a double window frame type electromagnet that can be excited in the X direction and the Y direction by one electromagnet, and a charged particle beam irradiation apparatus including the scanning electromagnet.

がん治療法の一つとして、陽子あるいは炭素イオン等のイオンビームを患者の患部に照射する粒子線治療が知られている。陽子や炭素イオン等のイオンを高エネルギーで物質に入射すると、飛程の終端で多くの線量を周辺の物質に付与する。この性質を利用し、粒子線治療ではがん細胞で多くのエネルギーを失うように、イオンビームを患者に照射する。これにより、周囲の健康な組織に損傷を与えることなく、がん細胞を破壊できる。粒子線治療ではイオンビームの空間的な広がり、照射位置、エネルギーを調整し、患部の形状に合わせた線量分布を形成する。   As one of the cancer treatment methods, particle beam therapy is known in which an affected area of a patient is irradiated with an ion beam of protons or carbon ions. When ions such as protons and carbon ions are incident on a substance with high energy, a large dose is given to surrounding substances at the end of the range. Taking advantage of this property, ion beam irradiation is applied to the patient so that the ion beam therapy loses a lot of energy in the cancer cells. This can destroy cancer cells without damaging surrounding healthy tissue. In particle beam therapy, the spatial spread, irradiation position, and energy of the ion beam are adjusted to form a dose distribution that matches the shape of the affected area.

粒子線治療に用いる粒子線治療システムは、主に、イオン源、イオン源で発生したイオンを加速する加速器、加速器から出射したイオンビームを輸送するビーム輸送装置、所望の形状で患部にビームを照射する照射装置を備える。   The particle beam therapy system used for particle beam therapy mainly includes an ion source, an accelerator for accelerating ions generated from the ion source, a beam transport device for transporting an ion beam emitted from the accelerator, and irradiating the affected part with a beam in a desired shape An irradiation device is provided.

粒子線治療システムで用いられる加速器には、シンクロトロンやサイクロトロン等が挙げられる。どちらの加速器も入射したイオンを所定のエネルギーまで加速し、イオンビームとして出射する機能は共通である。   Examples of the accelerator used in the particle beam therapy system include a synchrotron and a cyclotron. Both accelerators share the function of accelerating the incident ions to a predetermined energy and emitting them as ion beams.

加速器から出射されたイオンビームはビーム輸送装置によって照射装置まで輸送される。ビーム輸送装置にはイオンビームの進行方向を変える偏向電磁石とステアリング電磁石、イオンビームに収束、発散の作用を与える四極電磁石などが備えられており、これらの電磁石の励磁量を適切に調整することで、適切なサイズ、位置のビームが照射装置まで輸送される。   The ion beam emitted from the accelerator is transported to the irradiation device by the beam transport device. The beam transport device is equipped with a deflecting electromagnet that changes the traveling direction of the ion beam, a steering electromagnet, and a quadrupole electromagnet that converges and diverges the ion beam. By appropriately adjusting the excitation amount of these electromagnets A beam of the appropriate size and position is transported to the irradiation device.

照射装置は、一般に、ビームの経路中の最も下流に備えられている。照射装置では、患部形状に合わせたイオンビームの照射野を形成する。照射装置での照射野形成の方法の例として、ウォブラー法とスキャニング照射法が知られている。どちらの照射装置も照射装置の上流部に走査電磁石を備え、走査電磁石により励磁された磁場をビームが通過することにより、ビームは偏向され、患部に対し一様な線量分布を付与する。   The irradiation device is generally provided in the most downstream in the beam path. In the irradiation apparatus, an ion beam irradiation field is formed in accordance with the shape of the affected part. As an example of a method for forming an irradiation field with an irradiation apparatus, a wobbler method and a scanning irradiation method are known. Both irradiation devices include a scanning electromagnet upstream of the irradiation device, and the beam is deflected when the beam passes through the magnetic field excited by the scanning electromagnet, thereby giving a uniform dose distribution to the affected area.

ウォブラー法では、走査電磁石の下流にビームの飛程を調整するエネルギー吸収体、照射範囲を設定するコリメータを配置する。走査電磁石は、X方向磁場とY方向磁場を発生させ、各磁場を励磁する電流を正弦波で変化させることで、ビームを進行方向に直交する平面内で円を描くように走査する。一方、コリメータにより患部の外側へ向かうビームは遮断され、患部には一様に近い線量分布が形成される。   In the wobbler method, an energy absorber that adjusts the range of the beam and a collimator that sets the irradiation range are arranged downstream of the scanning electromagnet. The scanning electromagnet generates a magnetic field in the X direction and a magnetic field in the Y direction, and changes the current for exciting each magnetic field with a sine wave, thereby scanning the beam so as to draw a circle in a plane orthogonal to the traveling direction. On the other hand, the beam directed to the outside of the affected area is blocked by the collimator, and a nearly uniform dose distribution is formed in the affected area.

スキャニング照射法の一例として、スポットスキャニング照射法について説明する。走査電磁石は、X方向磁場とY方向磁場を発生させ、各磁場を励磁する電流量を制御することで、ビームを進行方向に直交する平面内の所定のスポットに照射するように走査する。また、患部形状に一致した照射野を形成するために、加速器から出射されるビームのエネルギーを変更するか、あるいはビーム輸送装置に配置されたエネルギー吸収体の厚みを変えることで、照射装置に輸送されるビームのエネルギーを変更する。これにより、ビームのエネルギーによってブラッグピークの位置が変わり、患部形状に合わせた照射野が形成される。また、任意の方向からの照射を可能にするために、回転ガントリーに搭載されている照射装置もある。   As an example of the scanning irradiation method, the spot scanning irradiation method will be described. The scanning electromagnet generates a X-direction magnetic field and a Y-direction magnetic field, and controls the amount of current that excites each magnetic field, thereby scanning the beam to irradiate a predetermined spot in a plane orthogonal to the traveling direction. In addition, in order to form an irradiation field that matches the shape of the affected area, the energy of the beam emitted from the accelerator is changed, or the thickness of the energy absorber disposed in the beam transport device is changed, so that it is transported to the irradiation device. Change the energy of the emitted beam. As a result, the position of the Bragg peak changes depending on the energy of the beam, and an irradiation field matching the shape of the affected area is formed. There is also an irradiation device mounted on the rotating gantry to enable irradiation from an arbitrary direction.

ウォブラー法、スキャニング照射法のどちらにおいても一般的に、X方向磁場を励磁する電磁石とY方向磁場を励磁する電磁石の2つの電磁石を、ビーム進行方向に対し直列に配置する(第1従来技術)。   In both the wobbler method and the scanning irradiation method, generally two electromagnets, an electromagnet that excites the X-direction magnetic field and an electromagnet that excites the Y-direction magnetic field, are arranged in series in the beam traveling direction (first conventional technology). .

ところで、粒子線治療システムは、加速器やビーム輸送装置や照射装置などの各機器から構成され、設置には数十メートル四方の敷地が必要である。粒子線治療システムの低コスト化には、設置面積の低減が有効である。その一つとして、照射装置の小型化が検討されている。照射装置を小型軽量化することにより、回転ガントリーも小型化でき、建屋の小型化にもなり、その結果、システム全体の小型化、低コスト化を図ることができる。   By the way, the particle beam therapy system is composed of various devices such as an accelerator, a beam transport device, and an irradiation device, and installation requires a site of several tens of meters. To reduce the cost of the particle beam therapy system, it is effective to reduce the installation area. As one of them, downsizing of the irradiation apparatus is being studied. By reducing the size and weight of the irradiation device, the rotating gantry can be reduced in size and the building can be reduced in size. As a result, the entire system can be reduced in size and cost.

例えば、非特許文献1には、二重窓枠型電磁石が提案されている(第2従来技術)。この二重窓枠型電磁石は、一台の電磁石でX方向磁場とY方向磁場の2つの磁場を励磁できる。X方向磁場とY方向磁場とをベクトル合成することで任意の磁場を励磁できる。二重窓枠型電磁石を用いる第2従来技術は、2つの電磁石を直列に配置する第1従来技術に比べて、走査電磁石から照射点までの距離が短くなり、照射装置の小型化を図ることができる。   For example, Non-Patent Document 1 proposes a double window frame type electromagnet (second prior art). This double window frame type electromagnet can excite two magnetic fields of an X direction magnetic field and a Y direction magnetic field with one electromagnet. An arbitrary magnetic field can be excited by vector synthesis of the X direction magnetic field and the Y direction magnetic field. The second prior art using a double window frame type electromagnet is shorter in distance from the scanning electromagnet to the irradiation point than the first prior art in which two electromagnets are arranged in series, and the irradiation apparatus is downsized. Can do.

Vladimir Anferov他 「Combined X-Y scanning magnet for conformal proton radiation therapy」Medical Physics 32(3), 2005年3月Vladimir Anferov et al. "Combined XY scanning magnet for conformal proton radiation therapy" Medical Physics 32 (3), March 2005

しかし、二重窓枠型電磁石(第2従来技術)では、異なる系統のコイルが互いに干渉して、いわゆる六極磁場が発生し、周辺部において一様磁場領域とならない。一様磁場領域から外れたビームはビームサイズが元の値から変化する等、照射計画に通りの線量を患部に付与できない恐れがある。大きな一様磁場領域が得られない結果、走査電磁石の内部でのビーム通過領域を第1従来技術に比べて狭くせざるを得ず、ビームの走査範囲に制限が課されてしまう。   However, in the double window frame type electromagnet (second prior art), coils of different systems interfere with each other to generate a so-called hexapole magnetic field and do not become a uniform magnetic field region in the peripheral portion. A beam deviating from the uniform magnetic field region may not be able to give a dose according to the irradiation plan to the affected area because the beam size changes from the original value. As a result of not being able to obtain a large uniform magnetic field region, the beam passing region inside the scanning electromagnet has to be narrower than that of the first prior art, and the beam scanning range is limited.

X方向磁場を励磁する電磁石とY方向磁場を励磁する電磁石の2つの電磁石を用いる第1従来技術の場合、それぞれの電磁石において、コイルのギャップに比べて磁極幅を長くする(X・Y非対称)ことにより、上記の課題を軽減できる。   In the case of the first prior art using two electromagnets, an electromagnet that excites an X-direction magnetic field and an electromagnet that excites a Y-direction magnetic field, the magnetic pole width of each electromagnet is made longer than the gap of the coil (XY asymmetry). As a result, the above problems can be reduced.

しかし、二重窓枠型電磁石は、X方向磁場とY方向磁場の2方向の磁場を励磁するため、その磁極形状はXとYが対称(直線Y=Xに対し対称)となる。第1従来技術のようにX・Y非対称とすることはできない。   However, since the double window frame type electromagnet excites the magnetic field in two directions of the X direction magnetic field and the Y direction magnetic field, the magnetic pole shape is symmetric with respect to X and Y (symmetric with respect to the straight line Y = X). As in the first prior art, it cannot be made XY asymmetry.

本発明の目的は、X方向磁場とY方向磁場の2方向の磁場を励磁する二重窓枠型電磁石において、一様磁場領域を広く取ることにより、X方向磁場を励磁する電磁石とY方向磁場を励磁する電磁石の2つの電磁石を用いる場合(第1従来技術)と同等のビーム走査範囲を維持できる走査電磁石を提供することである。   An object of the present invention is to provide a double window frame type electromagnet that excites two magnetic fields, an X direction magnetic field and a Y direction magnetic field, by widening a uniform magnetic field region, thereby exciting the X direction magnetic field and the Y direction magnetic field. It is to provide a scanning electromagnet that can maintain a beam scanning range equivalent to that in the case of using two electromagnets of the electromagnet that excites (a first prior art).

(1)上記目的を達成するために、本発明は、磁極周りに巻かれた複数のX方向磁場励磁用コイルと、前記磁極周りに巻かれた複数のY方向磁場励磁用コイルと備えた二重窓枠型電磁石であって、前記磁極内であって、前記複数のX方向磁場励磁用コイルに電流が流れる領域は、X方向磁場励磁電流通過メイン領域とX方向磁場励磁電流通過サブ領域から構成され、前記磁極内であって、前記複数のY方向磁場励磁用コイルに電流が流れる領域は、Y方向磁場励磁電流通過メイン領域とY方向磁場励磁電流通過サブ領域から構成され、前記X方向磁場励磁電流通過サブ領域は、前記Y方向磁場励磁電流通過メイン領域と前記Y方向磁場励磁電流通過サブ領域の間に配置され、X方向磁場励磁時に前記X方向磁場励磁電流通過メイン領域に発生するY方向磁場の影響を軽減し、前記Y方向磁場励磁電流通過サブ領域は、前記X方向磁場励磁電流通過メイン領域と前記X方向磁場励磁電流通過サブ領域の間に配置され、Y方向磁場励磁時に前記Y方向磁場励磁電流通過メイン領域に発生するX方向磁場の影響を軽減する。   (1) In order to achieve the above object, the present invention includes a plurality of X-direction magnetic field excitation coils wound around a magnetic pole and a plurality of Y-direction magnetic field excitation coils wound around the magnetic pole. A heavy window frame type electromagnet, wherein the current flows through the plurality of X direction magnetic field excitation coils within the magnetic poles from an X direction magnetic field excitation current passing main region and an X direction magnetic field excitation current passing subregion. The region in the magnetic pole, in which current flows through the plurality of Y-direction magnetic field excitation coils, includes a Y-direction magnetic field excitation current passing main region and a Y-direction magnetic field excitation current passing sub-region, and the X direction The magnetic field excitation current passing sub-region is disposed between the Y-direction magnetic field excitation current passing main region and the Y-direction magnetic field excitation current passing sub-region, and is generated in the X-direction magnetic field excitation current passing main region during X-direction magnetic field excitation. The Y-direction magnetic field excitation current passing sub-region is disposed between the X-direction magnetic field excitation current-passing main region and the X-direction magnetic field excitation current-passing sub-region. Sometimes, the influence of the X-direction magnetic field generated in the Y-direction magnetic field excitation current passing main region is reduced.

このように構成した本発明においては、例えば、Y方向磁場励磁の場合、Y方向磁場励磁電流通過メイン領域に隣接するX方向磁場励磁電流通過サブ領域は励磁されない。従って、従来技術に比べてX方向の磁場は軽減される。   In the present invention configured as described above, for example, in the case of Y-direction magnetic field excitation, the X-direction magnetic field excitation current passing sub-region adjacent to the Y-direction magnetic field excitation current passing main region is not excited. Therefore, the magnetic field in the X direction is reduced compared to the prior art.

更に、X方向磁場励磁電流通過メイン領域に隣接するY方向磁場励磁電流通過サブ領域はX方向に発生する磁場の向きをY方向に変える様に作用する。   Further, the Y-direction magnetic field excitation current passage sub-region adjacent to the X-direction magnetic field excitation current passage main region acts to change the direction of the magnetic field generated in the X direction to the Y direction.

これらの作用により、六極磁場の影響は軽減され、第2従来技術に比べて大きな一様磁場領域が得られる。すなわち、第1従来技術と同等の一様磁場領域が得られる。   By these actions, the influence of the hexapole magnetic field is reduced, and a large uniform magnetic field region can be obtained as compared with the second prior art. That is, a uniform magnetic field region equivalent to the first prior art can be obtained.

(2)上記(1)において、好ましくは、前記磁極が断面正方形の筒状体である。   (2) In the above (1), preferably, the magnetic pole is a cylindrical body having a square section.

磁極断面が正方形であることにより、二重窓枠型電磁石はX・Y対称な断面形状となる。   Since the magnetic pole cross section is square, the double window frame type electromagnet has an X / Y symmetrical cross section.

(3)上記(2)において、好ましくは、前記X方向磁場励磁電流通過サブ領域は、X方向磁場励磁電流通過第1サブ領域とX方向磁場励磁電流通過第2サブ領域とから構成され、前記Y方向磁場励磁電流通過サブ領域は、Y方向磁場励磁電流通過第1サブ領域とY方向磁場励磁電流通過第2サブ領域とから構成され、前記X方向磁場励磁電流通過メイン領域は、前記正方形の一の相対向する辺に配置され、前記Y方向磁場励磁電流通過メイン領域は、前記正方形の他の相対向する辺に配置され、前記X方向磁場励磁電流通過第1サブ領域は、前記Y方向磁場励磁電流通過第1サブ領域と前記Y方向磁場励磁電流通過第2サブ領域の間に配置され、前記X方向磁場励磁電流通過第2サブ領域は、前記Y方向磁場励磁電流通過メイン領域と前記Y方向磁場励磁電流通過第1サブ領域の間に配置され、前記Y方向磁場励磁電流通過第1サブ領域は、前記X方向磁場励磁電流通過第1サブ領域と前記X方向磁場励磁電流通過第2サブ領域の間に配置され、前記Y方向磁場励磁電流通過第2サブ領域は、前記X方向磁場励磁電流通過メイン領域と前記X方向磁場励磁電流通過第1サブ領域の間に配置される。   (3) In the above (2), preferably, the X-direction magnetic field excitation current passing sub-region is composed of an X-direction magnetic field excitation current passing first sub-region and an X-direction magnetic field excitation current passing second sub-region, The Y-direction magnetic field excitation current passage sub-region includes a Y-direction magnetic field excitation current passage first sub-region and a Y-direction magnetic field excitation current passage second sub-region, and the X-direction magnetic field excitation current passage main region has the square shape. The Y-direction magnetic field excitation current passing main region is disposed on the other opposite sides of the square, and the X-direction magnetic field excitation current passing first sub-region is disposed in the Y direction. The magnetic field excitation current passage first sub-region and the Y-direction magnetic field excitation current passage second sub-region are disposed, and the X-direction magnetic field excitation current passage second sub-region is formed between the Y-direction magnetic field excitation current passage main region and the Y-direction magnetic field excitation current passage main region. The Y-direction magnetic field excitation current passage first sub-region is disposed between the X-direction magnetic field excitation current passage first sub-region and the X-direction magnetic field excitation current passage second sub-region. The Y-direction magnetic field excitation current passage second subregion is disposed between the X-direction magnetic field excitation current passage main region and the X-direction magnetic field excitation current passage first subregion.

(4)上記(1)において、好ましくは、前記磁極が円筒体である。   (4) In the above (1), preferably, the magnetic pole is a cylindrical body.

磁極断面が円形であることにより、二重窓枠型電磁石はX・Y対称な断面形状となる。   Due to the circular cross section of the magnetic pole, the double window frame type electromagnet has an X / Y symmetrical cross section.

(5)上記(1)の走査電磁石は、好ましくは、荷電粒子ビーム照射装置に備えられる。   (5) The scanning electromagnet of (1) is preferably provided in a charged particle beam irradiation apparatus.

二重窓枠型電磁石により照射装置の小型化を図ることができる。その結果、システム全体の小型化、低コスト化を図ることができる。   The irradiation apparatus can be reduced in size by the double window frame type electromagnet. As a result, the entire system can be reduced in size and cost.

本発明によれば、二重窓枠型電磁石を用いることにより、X方向磁場を励磁する電磁石とY方向磁場を励磁する電磁石の2つの電磁石を用いる場合(第1従来技術)に比べて、照射装置の小型化を図ることができる。   According to the present invention, by using a double window frame type electromagnet, compared to the case of using two electromagnets, an electromagnet that excites an X-direction magnetic field and an electromagnet that excites a Y-direction magnetic field (first prior art), irradiation is performed. The size of the apparatus can be reduced.

また、第2従来技術のコイル配置を変更することで、一様磁場領域を広く取り、第1従来技術と同等のビーム走査範囲を維持できる。   In addition, by changing the coil arrangement of the second conventional technique, a uniform magnetic field region can be widened and the beam scanning range equivalent to the first conventional technique can be maintained.

粒子線治療システムの概略構成図である。It is a schematic block diagram of a particle beam therapy system. 照射装置の概略構成図である(第1実施形態)。It is a schematic block diagram of an irradiation apparatus (1st Embodiment). 走査電磁石の断面図である(第1実施形態)。It is sectional drawing of a scanning electromagnet (1st Embodiment). 走査電磁石の断面図である(従来技術)。It is sectional drawing of a scanning electromagnet (prior art). X方向の磁場分布を示す図である(Y方向励磁)。It is a figure which shows the magnetic field distribution of a X direction (Y direction excitation). Y方向の磁場分布を示す図である(Y方向励磁)。It is a figure which shows the magnetic field distribution of a Y direction (Y direction excitation). Y方向磁場を示す図ある(第1実施形態)It is a figure which shows a Y direction magnetic field (1st Embodiment). 走査電磁石の断面図である(第2実施形態)。It is sectional drawing of a scanning electromagnet (2nd Embodiment). 照射装置の概略構成図である(第3実施形態)。It is a schematic block diagram of an irradiation apparatus (3rd Embodiment). 走査電磁石の断面図である(第3実施形態)。It is sectional drawing of a scanning electromagnet (3rd Embodiment). 走査電磁石の断面図である(従来技術・円筒体)。It is sectional drawing of a scanning electromagnet (prior art and cylindrical body). X方向の磁場分布を示す図である(Y方向励磁)。It is a figure which shows the magnetic field distribution of a X direction (Y direction excitation). Y方向の磁場分布を示す図である(Y方向励磁)。It is a figure which shows the magnetic field distribution of a Y direction (Y direction excitation).

<第1実施形態>
以下、本発明の第1実施形態を図面を用いて説明する。
<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

〜構成〜
図1は本実施例における粒子線治療システム100の概略構成図である。本システム100は、イオン源200、入射用加速器300、主加速器400、ビーム輸送装置500、照射装置600から構成される。本システム100は陽子線を用いた治療装置であり、イオン源200で水素イオン、すなわち陽子を発生させ、入射用加速器300で予備加速されたイオンは主加速器400に入射される。主加速器400では患者ごとの治療計画によって計画されたビームの飛程に合わせたエネルギーまでビームが加速され、ビーム輸送装置500に出射される。出射されたビームはビーム輸送装置500によって適切なサイズに調整され、照射装置600まで輸送される。ビーム輸送装置500は、回転ガントリー510を有し、回転軸520を軸としてビーム輸送装置500と、それに接続された照射装置600が回転する。これにより、患者ごとの治療計画によって定められた照射方向から、照射点700にビームが照射される。
~Constitution~
FIG. 1 is a schematic configuration diagram of a particle beam therapy system 100 in the present embodiment. The system 100 includes an ion source 200, an incident accelerator 300, a main accelerator 400, a beam transport device 500, and an irradiation device 600. This system 100 is a treatment apparatus using proton beams, and hydrogen ions, that is, protons are generated by the ion source 200 and ions preliminarily accelerated by the incident accelerator 300 are incident on the main accelerator 400. In the main accelerator 400, the beam is accelerated to the energy that matches the range of the beam planned by the treatment plan for each patient, and is emitted to the beam transport device 500. The emitted beam is adjusted to an appropriate size by the beam transport device 500 and transported to the irradiation device 600. The beam transport apparatus 500 has a rotating gantry 510, and the beam transport apparatus 500 and the irradiation apparatus 600 connected thereto rotate around the rotating shaft 520. Thereby, the irradiation point 700 is irradiated with the beam from the irradiation direction determined by the treatment plan for each patient.

図2は照射装置600の概略構成図である。照射装置600はスキャニング照射法の照射装置である。図示上方からビームが入射され、走査電磁石610によるビーム軌道に垂直な磁場成分からの力により偏向され、照射点700に対し、所定の走査範囲710内でビームを走査できる。走査電磁石610の下流にはビーム位置を確認するビーム位置モニタ620が設置されており、このモニタ620によって照射中に、有感部621を通過したビーム位置を測定し、その照射位置を確認している。   FIG. 2 is a schematic configuration diagram of the irradiation apparatus 600. The irradiation device 600 is a scanning irradiation method irradiation device. A beam is incident from above and is deflected by a force from a magnetic field component perpendicular to the beam trajectory by the scanning electromagnet 610, so that the irradiation point 700 can be scanned within a predetermined scanning range 710. A beam position monitor 620 for confirming the beam position is installed downstream of the scanning electromagnet 610. During irradiation, the beam position that has passed through the sensitive part 621 is measured by this monitor 620, and the irradiation position is confirmed. Yes.

図2では、走査電磁石610のコイルの一部のみ図示している。走査電磁石610にはX方向磁場励磁用コイル611とY方向磁場励磁量コイル612が備えられており、それぞれのコイル611、612にはX方向磁場励磁用電源(図示せず)とY方向磁場励磁用電源(図示せず)がそれぞれ接続されており、治療計画装置によって計画された患者ごとのビーム照射位置と照射経路に従って、制御装置からの指令によって計算した電流パターンを出力する。   In FIG. 2, only a part of the coil of the scanning electromagnet 610 is illustrated. The scanning electromagnet 610 is provided with an X-direction magnetic field excitation coil 611 and a Y-direction magnetic field excitation amount coil 612. Each of the coils 611 and 612 has an X-direction magnetic field excitation power source (not shown) and a Y-direction magnetic field excitation. A power source (not shown) is connected to each other, and a current pattern calculated by a command from the control device is output according to the beam irradiation position and irradiation path for each patient planned by the treatment planning device.

磁極613は断面正方形の筒状体をしており、窓枠状の厚さ約0.5mmの電磁鋼板を積層したものである。その平面形状は正方形であり、ビーム通過領域615も正方形である。照射装置600の長さは走査電磁石の磁場と照射野サイズの比で決められている。例えば、片側ビームサイズが5mm、運動エネルギー220MeVの陽子線を一辺400mmの正方形の範囲で、最大磁場0.2T、磁極長700mmの電磁石で走査する。走査電磁石の下流側の端面と照射点の距離は2900mmとなる。一方、一様磁場領域615は一辺54mmの正方形となる。   The magnetic pole 613 has a cylindrical body with a square cross section, and is a laminate of electromagnetic steel plates having a window frame shape thickness of about 0.5 mm. The planar shape is a square, and the beam passage region 615 is also a square. The length of the irradiation device 600 is determined by the ratio between the magnetic field of the scanning electromagnet and the irradiation field size. For example, a proton beam with a one-side beam size of 5 mm and a kinetic energy of 220 MeV is scanned with an electromagnet having a maximum magnetic field of 0.2 T and a magnetic pole length of 700 mm within a square range of 400 mm on a side. The distance between the end face on the downstream side of the scanning electromagnet and the irradiation point is 2900 mm. On the other hand, the uniform magnetic field region 615 is a square with a side of 54 mm.

X方向磁場励磁用コイル611とY方向磁場励磁用コイル612が磁極613周りに巻かれている。   An X-direction magnetic field excitation coil 611 and a Y-direction magnetic field excitation coil 612 are wound around the magnetic pole 613.

図3は、走査電磁石610の断面図である。X方向磁場励磁用コイル611は複数のコイルから構成され、磁極内のコイル101〜120を無地で示す。Y方向磁場励磁用コイル612は複数のコイルから構成され、磁極内のコイル201〜220をハッチングで示す。本発明の特徴的構成は各コイルの配置にある。   FIG. 3 is a cross-sectional view of the scanning electromagnet 610. The X-direction magnetic field excitation coil 611 is composed of a plurality of coils, and the coils 101 to 120 in the magnetic poles are shown as plain. The Y-direction magnetic field excitation coil 612 includes a plurality of coils, and the coils 201 to 220 in the magnetic poles are indicated by hatching. The characteristic configuration of the present invention resides in the arrangement of each coil.

図示正方形上側には、コイル102〜107が配置され、図示正方形下側には、コイル112〜117が配置され、X方向磁場励磁電流通過メイン領域121,122を構成している。図示正方形右側には、コイル202〜207が配置され、図示正方形左側には、コイル212〜217が配置され、Y方向磁場励磁電流通過メイン領域221,222を構成している。   The coils 102 to 107 are disposed on the upper side of the illustrated square, and the coils 112 to 117 are disposed on the lower side of the illustrated square to configure the X-direction magnetic field excitation current passing main regions 121 and 122. Coils 202 to 207 are arranged on the right side of the square in the figure, and coils 212 to 217 are arranged on the left side of the square in the figure to constitute the Y-direction magnetic field excitation current passing main regions 221 and 222.

図示正方形上側において、コイル101は、コイル218とコイル219との間に配置され、コイル108は、コイル201とコイル220との間に配置され、図示正方形下側において、コイル111は、コイル208とコイル209との間に配置され、コイル118は、コイル211とコイル210との間に配置され、それぞれ、X方向磁場励磁電流通過第1サブ領域を構成している。   On the upper side of the illustrated square, the coil 101 is disposed between the coil 218 and the coil 219, the coil 108 is disposed between the coil 201 and the coil 220, and on the lower side of the illustrated square, the coil 111 is connected to the coil 208. The coil 118 is disposed between the coil 209, and the coil 118 is disposed between the coil 211 and the coil 210. Each of the coils 118 constitutes an X-direction magnetic field excitation current passing first subregion.

図示正方形右側において、コイル109は、メイン領域221とコイル201との間に配置され、コイル110は、メイン領域221とコイル208との間に配置され、図示正方形左側において、コイル119は、メイン領域222とコイル211との間に配置され、コイル120は、メイン領域222とコイル218との間に配置され、それぞれ、X方向磁場励磁電流通過第2サブ領域を構成している。   On the right side of the square, the coil 109 is disposed between the main region 221 and the coil 201, the coil 110 is disposed between the main region 221 and the coil 208, and on the left side of the square, the coil 119 is disposed on the main region. The coil 120 is disposed between the main region 222 and the coil 218, and each constitutes an X-direction magnetic field excitation current passing second sub-region.

図示正方形右側において、コイル201は、コイル108とコイル109との間に配置され、コイル208は、コイル111とコイル110との間に配置され、図示正方形左側において、コイル211は、コイル118とコイル119との間に配置され、コイル218は、コイル101とコイル120との間に配置され、それぞれ、Y方向磁場励磁電流通過第1サブ領域を構成している。   On the right side of the square shown, the coil 201 is disposed between the coil 108 and the coil 109, the coil 208 is disposed between the coil 111 and the coil 110, and on the left side of the square illustrated, the coil 211 is composed of the coil 118 and the coil 110. The coil 218 is disposed between the coil 101 and the coil 120, and constitutes a Y-direction magnetic field excitation current passing first sub-region.

図示正方形上側において、コイル219は、メイン領域121とコイル101との間に配置され、コイル220は、メイン領域121とコイル108との間に配置され、図示正方形下側において、コイル209は、メイン領域122とコイル111との間に配置され、コイル210は、メイン領域122とコイル118との間に配置され、それぞれ、Y方向磁場励磁電流通過第2サブ領域を構成している。   On the upper side of the square shown in the figure, the coil 219 is arranged between the main area 121 and the coil 101, the coil 220 is arranged between the main area 121 and the coil 108, and on the lower side of the square shown in the figure, the coil 209 is connected to the main area 121. It arrange | positions between the area | region 122 and the coil 111, and the coil 210 is arrange | positioned between the main area | region 122 and the coil 118, and each comprises the Y direction magnetic field excitation current passage 2nd sub area | region.

X方向磁場励磁用コイル611では、電源からコイル101〜120まで順次直列接続され電源に戻る回路が構成されている。X方向磁場励磁用コイル611に電流を流した場合は図示X方向に磁場が励磁される。Y方向磁場励磁用コイル612では、別の電源からコイル201〜220まで順次直列接続され電源に戻る回路が構成されている。Y方向磁場励磁用コイル612に電流を流した場合は図示Y方向に磁場が励磁される。異なるコイル通過領域を通過するコイル間の接続は磁極外のコイル接続部614(図2参照)を介して行われている。   In the X-direction magnetic field excitation coil 611, a circuit is configured in which a power supply to the coils 101 to 120 are sequentially connected in series and returned to the power supply. When a current is passed through the X direction magnetic field excitation coil 611, the magnetic field is excited in the X direction shown in the figure. In the Y-direction magnetic field excitation coil 612, a circuit is configured in which the coils 201 to 220 are sequentially connected in series from another power source and returned to the power source. When a current is passed through the Y-direction magnetic field excitation coil 612, the magnetic field is excited in the Y direction shown in the figure. Connections between coils passing through different coil passage regions are made via a coil connection portion 614 (see FIG. 2) outside the magnetic pole.

〜作用・効果〜
従来技術に係る二重窓枠型電磁石(第2従来技術)と比較することにより、本実施形態の効果を説明する。
-Action and effect-
The effect of this embodiment will be described by comparing with a double window frame type electromagnet (second prior art) according to the prior art.

図4は、従来技術に係る走査電磁石の断面図である。本実施形態のX方向磁場励磁用コイル109,110,119,120の配置位置に、Y方向磁場励磁用コイル231,232,233,234が配置され、本実施形態のY方向磁場励磁用コイル219,220,209,210の配置位置に、X方向磁場励磁用コイル131,132,133,134が配置される。   FIG. 4 is a cross-sectional view of a scanning electromagnet according to the prior art. The Y-direction magnetic field excitation coils 231, 232, 233, and 234 are disposed at the positions where the X-direction magnetic field excitation coils 109, 110, 119, and 120 according to this embodiment are disposed, and the Y-direction magnetic field excitation coil 219 according to this embodiment. , 220, 209, 210 are arranged in the X direction magnetic field exciting coils 131, 132, 133, 134.

すなわち、従来技術においては、正方形の上側および下側全域に、X方向磁場励磁電流通過領域が構成され、正方形の右側および左側全域に、Y方向磁場励磁電流通過領域が構成される。メイン領域、サブ領域といった区分はない(全てメイン領域)。   That is, in the prior art, an X-direction magnetic field excitation current passing region is configured in the entire upper and lower sides of the square, and a Y-direction magnetic field excitation current passing region is configured in the entire right and left sides of the square. There is no division such as main area and sub area (all main areas).

ところで、鉄や電磁鋼などの磁性体の最大比透磁率はおおよそ5000から8000程度である。このような比透磁率の大きい磁性体のまわりに生じる磁場は磁性体表面に対しほぼ垂直な方向に生じる。この性質を用い、窓枠型電磁石では長方形の開口を持つ磁性体を磁極として用いる。例えば、長方形開口部の左右の端に設けられた励磁用コイルに互いに逆向きの電流を流すことで、開口部内に上下方向の磁場を励起できる。   By the way, the maximum relative permeability of a magnetic material such as iron or electromagnetic steel is about 5000 to 8000. A magnetic field generated around a magnetic body having such a high relative permeability is generated in a direction substantially perpendicular to the surface of the magnetic body. Using this property, a window frame type electromagnet uses a magnetic body having a rectangular opening as a magnetic pole. For example, a vertical magnetic field can be excited in the opening by flowing currents in opposite directions to excitation coils provided at the left and right ends of the rectangular opening.

X方向磁場とY方向磁場の2方向の磁場を励磁する二重窓枠型電磁石においては、磁極および開口部の形状は正方形となる。X方向磁場励磁用コイル611に電流を流した場合は図示X方向に磁場が励磁され、Y方向磁場励磁用コイル612に電流を流した場合は図示Y方向に磁場が励磁される。   In a double window frame type electromagnet that excites a magnetic field in two directions of an X-direction magnetic field and a Y-direction magnetic field, the shapes of the magnetic pole and the opening are square. When a current is passed through the X direction magnetic field excitation coil 611, the magnetic field is excited in the X direction shown in the figure. When a current is passed through the Y direction magnetic field excitation coil 612, the magnetic field is excited in the Y direction shown in the figure.

従来技術の課題について説明する。例えば、Y方向磁場励磁用コイル612によりY方向に磁場が励磁される場合、二極磁場である。しかしながら、Y方向磁場励磁用コイル612周辺では、僅かながらX方向の磁場が生じる。このX方向磁場は中心からの距離の2乗に比例するように開口部の端に向けて大きくなっていく。その結果、特にコイル201,208,211,218周辺でのX方向磁場は無視できなくなり、いわゆる六極磁場となる。発生する磁場の概略を図4に追加する。   The problems of the prior art will be described. For example, when a magnetic field is excited in the Y direction by the Y-direction magnetic field excitation coil 612, the magnetic field is a dipole magnetic field. However, a slight X-direction magnetic field is generated around the Y-direction magnetic field exciting coil 612. This X-direction magnetic field increases toward the end of the opening so as to be proportional to the square of the distance from the center. As a result, the magnetic field in the X direction around the coils 201, 208, 211, and 218 cannot be ignored and becomes a so-called hexapole magnetic field. An outline of the generated magnetic field is added to FIG.

Y方向磁場に対し、X方向磁場は10-2から10-1程度の大きさとなるため、大きな一様磁場領域615が得られない。この課題を図5、図6において更に詳しく説明する。 Since the X direction magnetic field is about 10 −2 to 10 −1 with respect to the Y direction magnetic field, a large uniform magnetic field region 615 cannot be obtained. This problem will be described in more detail with reference to FIGS.

図5は、X方向の磁場分布を示す図であり、図6はY方向の磁場分布を示す図である。ともに、Y方向磁場励磁用コイル612によりY方向の磁場を励磁する場合、中心磁場で規格化した磁場について示している。従来技術の磁場分布について実線で示す。   FIG. 5 is a diagram showing the magnetic field distribution in the X direction, and FIG. 6 is a diagram showing the magnetic field distribution in the Y direction. In both cases, the magnetic field normalized by the central magnetic field when the magnetic field in the Y direction is excited by the Y-direction magnetic field exciting coil 612 is shown. The magnetic field distribution of the prior art is shown by a solid line.

X・Y方向ともに、中心から離れるに従って、六極磁場の影響が大きくなり、一様磁場でなくなる。   In both the X and Y directions, as the distance from the center increases, the influence of the hexapole magnetic field increases and the magnetic field is not uniform.

一方、本実施形態の構成は以下のように作用する。   On the other hand, the configuration of the present embodiment operates as follows.

図7は、走査電磁石610の断面図(図3)にY方向磁場励磁用コイル612により発生するY方向の磁場の概略を追加したものである。メイン領域221に隣接するX方向磁場励磁用コイル109,110およびメイン領域222に隣接するX方向磁場励磁用コイル119,120は励磁されない。従って、従来技術に比べてX方向の磁場は軽減される。   FIG. 7 is obtained by adding an outline of the magnetic field in the Y direction generated by the Y direction magnetic field exciting coil 612 to the sectional view of the scanning electromagnet 610 (FIG. 3). The X direction magnetic field excitation coils 109 and 110 adjacent to the main region 221 and the X direction magnetic field excitation coils 119 and 120 adjacent to the main region 222 are not excited. Therefore, the magnetic field in the X direction is reduced compared to the prior art.

更に、メイン領域121に隣接するY方向磁場励磁用コイル219,220およびメイン領域122に隣接するY方向磁場励磁用コイル209,210はX方向に発生する磁場の向きをY方向に変える様に作用する。   Further, the Y-direction magnetic field excitation coils 219 and 220 adjacent to the main region 121 and the Y-direction magnetic field excitation coils 209 and 210 adjacent to the main region 122 act to change the direction of the magnetic field generated in the X direction to the Y direction. To do.

これらの作用により、六極磁場の影響は軽減され、従来技術に比べて大きな一様磁場領域615が得られる。この効果を図5、図6において更に詳しく説明する。図5、図6に、本実施形態の磁場分布について破線で示す。   By these actions, the influence of the hexapole magnetic field is reduced, and a larger uniform magnetic field region 615 is obtained as compared with the prior art. This effect will be described in more detail with reference to FIGS. 5 and 6 show the magnetic field distribution of the present embodiment by broken lines.

X・Y方向ともに、中心から離れるに従って、六極磁場の影響が大きくなり、一様磁場でなくなるという傾向は従来技術と同じである。しかし、従来技術にくらべて、本実施形態のほうが、X・Y方向ともに、より広い範囲で磁場が一様である(規格磁場が1に近い)ことが分かる。したがって、より大きな一様磁場領域615が得られる。   In both the X and Y directions, as the distance from the center increases, the influence of the hexapole magnetic field increases and the tendency to lose the uniform magnetic field is the same as in the prior art. However, it can be seen that the magnetic field is more uniform in the X and Y directions in a wider range than the conventional technique (the standard magnetic field is close to 1). Therefore, a larger uniform magnetic field region 615 is obtained.

なお、Y方向磁場励磁の場合について述べたが、X方向磁場励磁の場合も同様である。   Although the case of Y-direction magnetic field excitation has been described, the same applies to the case of X-direction magnetic field excitation.

また、本実施形態は、二重窓枠型電磁石を用いることにより、照射装置の小型化を図ることができる。   Moreover, this embodiment can achieve size reduction of an irradiation apparatus by using a double window frame type electromagnet.

<第2実施形態>
〜構成〜
図8は、第2実施形態に係る走査電磁石の断面図である。第1実施形態(図3参照)のX方向磁場励磁用コイル109,110,119,120の配置位置に、Y方向磁場励磁用コイル231,232,233,234が配置され、第1実施形態のY方向磁場励磁用コイル219,220,209,210の配置位置に、X方向磁場励磁用コイル131,132,133,134が配置される。さらに、第1実施形態のX方向磁場励磁用コイル101,108,111,118の配置位置に、Y方向磁場励磁用コイル236,237,238,239が配置され、第1実施形態のY方向磁場励磁用コイル201,208,211,218の配置位置に、X方向磁場励磁用コイル136,137,138,139が配置される。
Second Embodiment
~Constitution~
FIG. 8 is a cross-sectional view of the scanning electromagnet according to the second embodiment. The Y-direction magnetic field excitation coils 231, 232, 233, and 234 are disposed at the arrangement positions of the X-direction magnetic field excitation coils 109, 110, 119, and 120 of the first embodiment (see FIG. 3). X-direction magnetic field excitation coils 131, 132, 133, and 134 are disposed at positions where the Y-direction magnetic field excitation coils 219, 220, 209, and 210 are disposed. Furthermore, Y-direction magnetic field excitation coils 236, 237, 238, and 239 are disposed at the positions where the X-direction magnetic field excitation coils 101, 108, 111, and 118 according to the first embodiment are arranged, and the Y-direction magnetic field according to the first embodiment. X-direction magnetic field excitation coils 136, 137, 138, and 139 are arranged at positions where the excitation coils 201, 208, 211, and 218 are arranged.

言い換えると、従来技術(図4参照)のX方向磁場励磁用コイル101,108,111,118の配置位置に、Y方向磁場励磁用コイル236,237,238,239が配置され、従来技術のY方向磁場励磁用コイル201,208,211,218の配置位置に、X方向磁場励磁用コイル136,137,138,139が配置される。   In other words, the Y-direction magnetic field excitation coils 236, 237, 238, and 239 are arranged at the arrangement positions of the X-direction magnetic field excitation coils 101, 108, 111, and 118 of the conventional technique (see FIG. 4). X direction magnetic field excitation coils 136, 137, 138, and 139 are disposed at the positions where the directional magnetic field excitation coils 201, 208, 211, and 218 are disposed.

すなわち、図示正方形上側には、コイル131,102〜107,132が配置され、図示正方形下側には、コイル133,112〜117,134が配置され、X方向磁場励磁電流通過メイン領域121,122を構成している。図示正方形右側には、コイル231,202〜207,232が配置され、図示正方形左側には、コイル233,212〜217,234が配置され、Y方向磁場励磁電流通過メイン領域221,222を構成している。   That is, the coils 131, 102 to 107, 132 are disposed on the upper side of the illustrated square, and the coils 133, 112 to 117, 134 are disposed on the lower side of the illustrated square, and the X direction magnetic field excitation current passing main regions 121, 122 are disposed. Is configured. Coils 231, 202 to 207, 232 are arranged on the right side of the illustrated square, and coils 233, 212 to 217, 234 are arranged on the left side of the illustrated square to constitute the Y direction magnetic field excitation current passing main regions 221, 222. ing.

図示正方形右側において、コイル136は、メイン領域221とコイル237との間に配置され、コイル137は、メイン領域221とコイル238との間に配置され、図示正方形左側において、コイル138は、メイン領域222とコイル239との間に配置され、コイル139は、メイン領域222とコイル236との間に配置され、それぞれ、X方向磁場励磁電流通過サブ領域を構成している。   On the right side of the illustrated square, the coil 136 is disposed between the main region 221 and the coil 237, the coil 137 is disposed between the main region 221 and the coil 238, and on the left side of the illustrated square, the coil 138 is disposed on the main region. The coil 139 is disposed between the main region 222 and the coil 236, and constitutes an X-direction magnetic field excitation current passing sub-region.

図示正方形上側において、コイル236は、メイン領域121とコイル139との間に配置され、コイル237は、メイン領域121とコイル136との間に配置され、図示正方形下側において、コイル238は、メイン領域122とコイル137との間に配置され、コイル239は、メイン領域122とコイル138との間に配置され、それぞれ、Y方向磁場励磁電流通過サブ領域を構成している。   The coil 236 is disposed between the main region 121 and the coil 139 on the upper side of the illustrated square, the coil 237 is disposed between the main region 121 and the coil 136, and the coil 238 is disposed on the lower side of the illustrated square. The coil 239 is disposed between the region 122 and the coil 137, and the coil 239 is disposed between the main region 122 and the coil 138, and each constitutes a Y-direction magnetic field excitation current passing sub-region.

〜作用・効果〜
第1実施形態と同様に、Y方向磁場励磁の場合を例に、本実施形態の作用・効果を説明する。発生するY方向の磁場の概略を図8に追加する。
-Action and effect-
As in the first embodiment, the operation and effect of this embodiment will be described by taking the case of Y-direction magnetic field excitation as an example. An outline of the generated magnetic field in the Y direction is added to FIG.

メイン領域221に隣接するX方向磁場励磁用コイル136,137およびメイン領域222に隣接するX方向磁場励磁用コイル138,139は励磁されない。従って、従来技術に比べてX方向の磁場は軽減される。   The X direction magnetic field excitation coils 136 and 137 adjacent to the main region 221 and the X direction magnetic field excitation coils 138 and 139 adjacent to the main region 222 are not excited. Therefore, the magnetic field in the X direction is reduced compared to the prior art.

更に、メイン領域121に隣接するY方向磁場励磁用コイル236,237およびメイン領域122に隣接するY方向磁場励磁用コイル238,239はX方向に発生する磁場の向きをY方向に変える様に作用する。   Further, the Y-direction magnetic field excitation coils 236 and 237 adjacent to the main region 121 and the Y-direction magnetic field excitation coils 238 and 239 adjacent to the main region 122 act to change the direction of the magnetic field generated in the X direction to the Y direction. To do.

これらの作用により、六極磁場の影響は軽減され、従来技術(図4参照)に比べて大きな一様磁場領域615が得られる。なお、Y方向磁場励磁の場合について述べたが、X方向磁場励磁の場合も同様である。   By these actions, the influence of the hexapole magnetic field is reduced, and a larger uniform magnetic field region 615 is obtained as compared with the prior art (see FIG. 4). Although the case of Y-direction magnetic field excitation has been described, the same applies to the case of X-direction magnetic field excitation.

<第3実施形態>
〜構成〜
第1実施形態および第2実施形態は、本発明を断面正方形の筒状体の磁極613に適用したものであるのに対し、第3実施形態は、本発明を円筒体の磁極616に適用したものである。
<Third Embodiment>
~Constitution~
In the first embodiment and the second embodiment, the present invention is applied to a cylindrical magnetic pole 613 having a square section, whereas in the third embodiment, the present invention is applied to a cylindrical magnetic pole 616. Is.

図9は照射装置600の概略構成図である。照射点700に対し半径200mmの範囲720でビームを走査するように、一様磁場領域617は一辺27mmの円形となる。   FIG. 9 is a schematic configuration diagram of the irradiation apparatus 600. The uniform magnetic field region 617 has a circular shape with a side of 27 mm so that the beam is scanned in a range 720 having a radius of 200 mm with respect to the irradiation point 700.

図10は、第3実施形態に係る走査電磁石610の断面図である。X方向磁場励磁用コイル611は複数のコイルから構成され、磁極内のコイル151〜166を無地で示す。Y方向磁場励磁用コイル612は複数のコイルから構成され、磁極内のコイル251〜266をハッチングで示す。   FIG. 10 is a cross-sectional view of a scanning electromagnet 610 according to the third embodiment. The X-direction magnetic field excitation coil 611 is composed of a plurality of coils, and the coils 151 to 166 in the magnetic poles are shown as plain. The Y-direction magnetic field exciting coil 612 is composed of a plurality of coils, and the coils 251 to 266 in the magnetic pole are indicated by hatching.

ここで、X軸を0°とし反時計回りに角度を規定する。説明の便宜上、45°〜135°の範囲を図示円周上側、135°〜225°の範囲を図示円周左側、225°〜315°の範囲を図示円周下側、315°〜405°(45°)の範囲を図示周右側と呼ぶ。   Here, the X axis is set to 0 °, and the angle is defined counterclockwise. For convenience of explanation, the range of 45 ° to 135 ° is the upper side of the circumference of the drawing, the range of 135 ° to 225 ° is the left side of the circumference of the drawing, the range of 225 ° to 315 ° is the lower side of the circumference of the drawing, 315 ° to 405 ° ( The range of 45 ° is referred to as the right side in the figure.

図示円周上側には、コイル151〜156が配置され、図示円周下側には、コイル159〜164が配置され、X方向磁場励磁電流通過メイン領域171,172を構成している。図示円形右側には、コイル252〜257が配置され、図示円周左側には、コイル260〜265が配置され、Y方向磁場励磁電流通過メイン領域271,272を構成している。   Coils 151 to 156 are arranged on the upper side in the figure, and coils 159 to 164 are arranged on the lower side in the figure to configure the X-direction magnetic field excitation current passing main regions 171 and 172. Coils 252 to 257 are arranged on the right side in the figure, and coils 260 to 265 are arranged on the left side in the figure to constitute the Y-direction magnetic field excitation current passing main regions 271 and 272.

図示円周右側において、コイル157は、メイン領域271とコイル251との間に配置され、コイル158は、メイン領域271とコイル258との間に配置され、図示円周左側において、コイル165は、メイン領域272とコイル259との間に配置され、コイル166は、メイン領域272とコイル266との間に配置され、それぞれ、X方向磁場励磁電流通過サブ領域を構成している。   On the right side of the illustrated circle, the coil 157 is disposed between the main region 271 and the coil 251, the coil 158 is disposed between the main region 271 and the coil 258, and on the left side of the illustrated circle, the coil 165 is Arranged between the main region 272 and the coil 259, the coil 166 is disposed between the main region 272 and the coil 266, and each constitutes an X-direction magnetic field excitation current passing sub-region.

図示円周上側において、コイル266は、メイン領域171とコイル166との間に配置され、コイル251は、メイン領域171とコイル157との間に配置され、図示円周下側において、コイル258は、メイン領域172とコイル158との間に配置され、コイル259は、メイン領域172とコイル165との間に配置され、それぞれ、Y方向磁場励磁電流通過サブ領域を構成している。   On the upper side in the figure, the coil 266 is disposed between the main area 171 and the coil 166, the coil 251 is disposed between the main area 171 and the coil 157, and on the lower side in the figure, the coil 258 is The coil 259 is disposed between the main region 172 and the coil 165, and constitutes a Y-direction magnetic field excitation current passing sub-region.

〜作用・効果〜
従来技術と比較することにより、本実施形態の効果を説明する。なお、従来技術の磁極613は断面正方形の筒状体であるが、従来技術に係るコイル配置(図4参照)を円筒体の磁極616に適用した場合を仮定して、本実施形態の従来技術とする。
-Action and effect-
The effect of this embodiment will be described by comparing with the prior art. The conventional magnetic pole 613 is a cylindrical body having a square cross section. However, assuming that the coil arrangement according to the conventional technique (see FIG. 4) is applied to the magnetic pole 616 of the cylindrical body, the prior art of this embodiment is used. And

図11は、従来技術に係るコイル配置を円筒体の磁極616に適用した場合の走査電磁石の断面図である。本実施形態のX方向磁場励磁用コイル157,158,165,166の配置位置に、Y方向磁場励磁用コイル281,282,283,284が配置され、本実施形態のY方向磁場励磁用コイル251,258,259,266の配置位置に、X方向磁場励磁用コイル181,182,183,184が配置される。   FIG. 11 is a cross-sectional view of a scanning electromagnet when a coil arrangement according to the prior art is applied to a magnetic pole 616 of a cylindrical body. Y direction magnetic field excitation coils 281, 282, 283, and 284 are disposed at positions where the X direction magnetic field excitation coils 157, 158, 165, and 166 of the present embodiment are disposed, and the Y direction magnetic field excitation coil 251 of the present embodiment. , 258, 259, and 266 are arranged X-direction magnetic field exciting coils 181, 182, 183, and 184.

すなわち、従来技術においては、円周の上側および下側全域に、X方向磁場励磁電流通過領域が構成され、円周の右側および左側全域に、Y方向磁場励磁電流通過領域が構成される。メイン領域、サブ領域といった区分はない。   That is, in the prior art, an X-direction magnetic field excitation current passing region is configured in the entire upper and lower sides of the circumference, and a Y-direction magnetic field excitation current passing region is configured in the entire right and left sides of the circumference. There is no division such as main area and sub area.

例えば、Y方向磁場励磁用コイル612によりY方向に磁場が励磁される場合、二極磁場である。しかしながら、Y方向磁場励磁用コイル612周辺では、僅かながらX方向の磁場が生じる。このX方向磁場は中心からの距離の2乗に比例するように開口部の端に向けて大きくなっていく。その結果、特にコイル281,282,283,284周辺でのX方向磁場は無視できなくなり、いわゆる六極磁場となり、大きな一様磁場領域617が得られない。この課題を図12、図13において更に詳しく説明する。   For example, when a magnetic field is excited in the Y direction by the Y-direction magnetic field excitation coil 612, the magnetic field is a dipole magnetic field. However, a slight X-direction magnetic field is generated around the Y-direction magnetic field exciting coil 612. This X-direction magnetic field increases toward the end of the opening so as to be proportional to the square of the distance from the center. As a result, the magnetic field in the X direction around the coils 281, 282, 283, and 284 is not negligible, and becomes a so-called hexapole magnetic field, and a large uniform magnetic field region 617 cannot be obtained. This problem will be described in more detail with reference to FIGS.

図12は、X方向の磁場分布を示す図であり、図13はY方向の磁場分布を示す図である。ともに、Y方向磁場励磁用コイル612によりY方向の磁場を励磁する場合、中心磁場で規格化した磁場について示している。従来技術の磁場分布について実線で示す。   FIG. 12 is a diagram illustrating the magnetic field distribution in the X direction, and FIG. 13 is a diagram illustrating the magnetic field distribution in the Y direction. In both cases, the magnetic field normalized by the central magnetic field when the magnetic field in the Y direction is excited by the Y-direction magnetic field exciting coil 612 is shown. The magnetic field distribution of the prior art is shown by a solid line.

X・Y方向ともに、中心から離れるに従って、六極磁場の影響が大きくなり、一様磁場でなくなる。発生する磁場の概略を図11に追加する。   In both the X and Y directions, as the distance from the center increases, the influence of the hexapole magnetic field increases and the magnetic field is not uniform. An outline of the generated magnetic field is added to FIG.

一方、本実施形態の磁場分布について破線で示す。X・Y方向ともに、中心から離れるに従って、六極磁場の影響が大きくなり、一様磁場でなくなるという傾向は従来技術と同じである。しかし、従来技術にくらべて、本実施形態のほうが、X・Y方向ともに、より広い範囲で磁場が一様である(規格磁場が1に近い)ことが分かる。   On the other hand, the magnetic field distribution of this embodiment is indicated by a broken line. In both the X and Y directions, as the distance from the center increases, the influence of the hexapole magnetic field increases and the tendency to lose the uniform magnetic field is the same as in the prior art. However, it can be seen that the magnetic field is more uniform in the X and Y directions in a wider range than the conventional technique (the standard magnetic field is close to 1).

本実施形態において発生するY方向の磁場の概略を図10に追加する。   An outline of the magnetic field in the Y direction generated in this embodiment is added to FIG.

メイン領域271に隣接するX方向磁場励磁用コイル157,158およびメイン領域272に隣接するX方向磁場励磁用コイル165,166は励磁されない。従って、従来技術に比べてX方向の磁場は軽減される。   The X direction magnetic field excitation coils 157 and 158 adjacent to the main region 271 and the X direction magnetic field excitation coils 165 and 166 adjacent to the main region 272 are not excited. Therefore, the magnetic field in the X direction is reduced compared to the prior art.

更に、メイン領域171に隣接するY方向磁場励磁用コイル251,266およびメイン領域172に隣接するY方向磁場励磁用コイル258,259はX方向に発生する磁場の向きをY方向に変える様に作用する。   Further, the Y-direction magnetic field excitation coils 251 and 266 adjacent to the main region 171 and the Y-direction magnetic field excitation coils 258 and 259 adjacent to the main region 172 act to change the direction of the magnetic field generated in the X direction to the Y direction. To do.

これらの作用により、六極磁場の影響は軽減され、従来技術(図11参照)に比べて大きな一様磁場領域617が得られる。なお、Y方向磁場励磁の場合について述べたが、X方向磁場励磁の場合も同様である。   By these actions, the influence of the hexapole magnetic field is reduced, and a larger uniform magnetic field region 617 is obtained as compared with the conventional technique (see FIG. 11). Although the case of Y-direction magnetic field excitation has been described, the same applies to the case of X-direction magnetic field excitation.

100 粒子線治療システム
200 イオン源
300 入射用加速器
400 主加速器
500 ビーム輸送装置
510 回転ガントリー
520 回転ガントリーの回転軸
600 照射装置
610 走査電磁石
611,101〜184 X方向磁場励磁用コイル
612,201〜284 Y方向磁場励磁用コイル
613,616 磁極
614 コイル接続部
615,617 一様磁場領域
616 走査電磁石の中心軸
620 ビーム位置モニタ
700 照射点
710,720 ビーム走査範囲
DESCRIPTION OF SYMBOLS 100 Particle beam therapy system 200 Ion source 300 Incident accelerator 400 Main accelerator 500 Beam transport device 510 Rotating gantry 520 Rotating gantry rotating shaft 600 Irradiating device 610 Scanning electromagnets 611, 101-184 X-direction magnetic field exciting coils 612, 201-284 Y direction magnetic field exciting coil 613, 616 Magnetic pole 614 Coil connection portion 615, 617 Uniform magnetic field region 616 Scanning magnet central axis 620 Beam position monitor 700 Irradiation point 710, 720 Beam scanning range

Claims (5)

磁極周りに巻かれた複数のX方向磁場励磁用コイルと、前記磁極周りに巻かれた複数のY方向磁場励磁用コイルと備えた二重窓枠型電磁石であって、
前記磁極内であって、前記複数のX方向磁場励磁用コイルに電流が流れる領域は、X方向磁場励磁電流通過メイン領域とX方向磁場励磁電流通過サブ領域から構成され、
前記磁極内であって、前記複数のY方向磁場励磁用コイルに電流が流れる領域は、Y方向磁場励磁電流通過メイン領域とY方向磁場励磁電流通過サブ領域から構成され、
前記X方向磁場励磁電流通過サブ領域は、前記Y方向磁場励磁電流通過メイン領域と前記Y方向磁場励磁電流通過サブ領域の間に配置され、X方向磁場励磁時に前記X方向磁場励磁電流通過メイン領域に発生するY方向磁場の影響を軽減し、
前記Y方向磁場励磁電流通過サブ領域は、前記X方向磁場励磁電流通過メイン領域と前記X方向磁場励磁電流通過サブ領域の間に配置され、Y方向磁場励磁時に前記Y方向磁場励磁電流通過メイン領域に発生するX方向磁場の影響を軽減する
ことを特徴とする走査電磁石。
A double window frame type electromagnet comprising a plurality of X direction magnetic field excitation coils wound around a magnetic pole and a plurality of Y direction magnetic field excitation coils wound around the magnetic pole;
A region in the magnetic pole, in which a current flows through the plurality of X-direction magnetic field excitation coils, includes an X-direction magnetic field excitation current passing main region and an X-direction magnetic field excitation current passing sub-region,
A region in the magnetic pole, in which a current flows through the plurality of Y-direction magnetic field excitation coils, includes a Y-direction magnetic field excitation current passing main region and a Y-direction magnetic field excitation current passing sub-region,
The X-direction magnetic field excitation current passage sub-region is disposed between the Y-direction magnetic field excitation current passage main region and the Y-direction magnetic field excitation current passage sub-region, and the X-direction magnetic field excitation current passage main region during X-direction magnetic field excitation. Reduce the influence of the Y-direction magnetic field generated in the
The Y-direction magnetic field excitation current passage sub-region is disposed between the X-direction magnetic field excitation current passage main region and the X-direction magnetic field excitation current passage sub-region, and the Y-direction magnetic field excitation current passage main region at the time of Y-direction magnetic field excitation. The scanning electromagnet characterized by reducing the influence of the X direction magnetic field which generate | occur | produces.
請求項1記載の走査電磁石において、
前記磁極が断面正方形の筒状体である
ことを特徴とする走査電磁石。
The scanning electromagnet according to claim 1, wherein
The magnetic pole is a cylindrical body having a square cross section.
請求項2記載の走査電磁石において、
前記X方向磁場励磁電流通過サブ領域は、X方向磁場励磁電流通過第1サブ領域とX方向磁場励磁電流通過第2サブ領域とから構成され、
前記Y方向磁場励磁電流通過サブ領域は、Y方向磁場励磁電流通過第1サブ領域とY方向磁場励磁電流通過第2サブ領域とから構成され、
前記X方向磁場励磁電流通過メイン領域は、前記正方形の一の相対向する辺に配置され、
前記Y方向磁場励磁電流通過メイン領域は、前記正方形の他の相対向する辺に配置され、
前記X方向磁場励磁電流通過第1サブ領域は、前記Y方向磁場励磁電流通過第1サブ領域と前記Y方向磁場励磁電流通過第2サブ領域の間に配置され、
前記X方向磁場励磁電流通過第2サブ領域は、前記Y方向磁場励磁電流通過メイン領域と前記Y方向磁場励磁電流通過第1サブ領域の間に配置され、
前記Y方向磁場励磁電流通過第1サブ領域は、前記X方向磁場励磁電流通過第1サブ領域と前記X方向磁場励磁電流通過第2サブ領域の間に配置され、
前記Y方向磁場励磁電流通過第2サブ領域は、前記X方向磁場励磁電流通過メイン領域と前記X方向磁場励磁電流通過第1サブ領域の間に配置される
ことを特徴とする走査電磁石。
The scanning electromagnet according to claim 2, wherein
The X-direction magnetic field excitation current passage sub-region is composed of an X-direction magnetic field excitation current passage first sub-region and an X-direction magnetic field excitation current passage second sub-region,
The Y-direction magnetic field excitation current passage sub-region is composed of a Y-direction magnetic field excitation current passage first sub-region and a Y-direction magnetic field excitation current passage second sub-region,
The X-direction magnetic field excitation current passing main region is disposed on one opposite side of the square,
The Y-direction magnetic field excitation current passing main region is disposed on the opposite side of the square,
The first X direction magnetic field excitation current passing sub-region is disposed between the first Y direction magnetic field excitation current passing sub region and the second Y direction magnetic field excitation current passing sub region.
The X direction magnetic field excitation current passing second sub-region is disposed between the Y direction magnetic field excitation current passing main region and the Y direction magnetic field excitation current passing first sub region,
The Y direction magnetic field excitation current passing first sub-region is disposed between the X direction magnetic field excitation current passing first sub region and the X direction magnetic field excitation current passing second sub region,
The Y-direction magnetic field excitation current passage second subregion is disposed between the X-direction magnetic field excitation current passage main region and the X-direction magnetic field excitation current passage first subregion.
請求項1記載の走査電磁石において、
前記磁極が円筒体である
ことを特徴とする走査電磁石。
The scanning electromagnet according to claim 1, wherein
The scanning electromagnet, wherein the magnetic pole is a cylindrical body.
請求項1記載の走査電磁石を備える荷電粒子ビーム照射装置。   A charged particle beam irradiation apparatus comprising the scanning electromagnet according to claim 1.
JP2011242476A 2011-11-04 2011-11-04 Scanning type electromagnet and charged particle beam irradiation device Pending JP2013096949A (en)

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Publication number Priority date Publication date Assignee Title
WO2016067820A1 (en) * 2014-10-28 2016-05-06 国立研究開発法人 放射線医学総合研究所 Charged particle beam irradiation device
JP2016083344A (en) * 2014-10-28 2016-05-19 国立研究開発法人放射線医学総合研究所 Charged particle beam irradiation device
CN111161902A (en) * 2020-01-17 2020-05-15 桂林狮达技术股份有限公司 Control method of multiphase winding deflection scanning device

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JPH05264797A (en) * 1992-03-17 1993-10-12 Hitachi Ltd Method and device for beam irradiation
JP2007260222A (en) * 2006-03-29 2007-10-11 Osaka Univ Charged particle beam deflector and irradiator

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Publication number Priority date Publication date Assignee Title
WO2016067820A1 (en) * 2014-10-28 2016-05-06 国立研究開発法人 放射線医学総合研究所 Charged particle beam irradiation device
JP2016083344A (en) * 2014-10-28 2016-05-19 国立研究開発法人放射線医学総合研究所 Charged particle beam irradiation device
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CN111161902A (en) * 2020-01-17 2020-05-15 桂林狮达技术股份有限公司 Control method of multiphase winding deflection scanning device
CN111161902B (en) * 2020-01-17 2020-09-22 桂林狮达技术股份有限公司 Control method of multiphase winding deflection scanning device

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