阅读说明：本技术 粒子束装置 (Particle beam device ) 是由 户内豊 于 2021-03-17 设计创作，主要内容包括：本发明的目的在于提供一种能够实现小型化及低成本化的粒子束装置。粒子束装置(1)具备偏转电磁体(15),该偏转电磁体(15)能够导入来自离子种类互不相同的第1离子源(11)及第2离子源(12)的各离子束(B1、B2),且能够通过切换磁场强度将离子束(B1、B2)中的一个选择性地射出至射束传输系统(19),偏转电磁体(15)具有：偏转功能,使应该射出至射束传输系统(19)的离子束向射束传输系统(19)偏转；及分析功能,减少混合在该离子束中的不同种类的射束朝射束传输系统(19)的射出。(The invention aims to provide a particle beam device which can realize miniaturization and low cost. A particle beam device (1) is provided with a deflection electromagnet (15), wherein the deflection electromagnet (15) can introduce ion beams (B1, B2) from a 1 st ion source (11) and a 2 nd ion source (12) which are different in ion species from each other, and can selectively emit one of the ion beams (B1, B2) to a beam transport system (19) by switching the magnetic field strength, and the deflection electromagnet (15) is provided with: a deflection function of deflecting the ion beam to be emitted to the beam transport system (19) toward the beam transport system (19); and an analysis function for reducing the emission of the different types of beams mixed in the ion beam toward a beam transport system (19).)

1. A particle beam device, wherein,

which is provided with an electromagnet and a magnetic field generating device,

a device in which the electromagnet can introduce each ion beam from a plurality of ion sources having different ion species from each other, and can selectively emit one of the ion beams to the downstream side by switching the magnetic field intensity,

the electromagnet has:

a deflection function of deflecting the ion beam to be emitted to the downstream device toward the downstream device; and

and an analyzing function of reducing emission of the different types of beams mixed in the ion beam to the downstream device.

2. The particle beam device of claim 1,

it is provided with a current measuring device,

one of the ion beams introduced to the electromagnet is incident to the current measuring device, which is capable of measuring a beam current of the ion beam,

one of the ion beams different from the ion beam toward the device on the downstream side is incident to the current measuring device.

3. The particle beam device of claim 2,

the current measuring device is arranged inside the electromagnet.

Technical Field

The present invention relates to a particle beam device.

Background

As a conventional particle beam device, for example, a particle beam device described in the following non-patent document 1 is known. The particle beam apparatus includes two ion sources so that two types of ion beams can be supplied to the beam accelerating apparatus. The two beam propagation paths from the respective ion sources are merged in an electromagnet, and the beam propagation paths extend further to the downstream side from the electromagnet, and the downstream end of the beam propagation path is provided with a beam acceleration device. Deflection electromagnets are respectively present on the beam transport path between each ion source and the electromagnets, and the ion beam from the ion source is deflected by about 90 ° by the deflection electromagnets and transported to the electromagnets of the junction.

Non-patent document 1: balbinot et al, BEAM DIAGNOSTICSIN THE CNAO INJETION LINES COMMISONING, Proceedings of DIPAC09, Basel, Switzerland, p119-121.

Non-patent document 2: tim Winkelmann et al, LONG-TERMOPERRATION EXPERIENCE WITH TWOECRION SOURCES AND PLANNED EXTENSION AT HIT, Proceedingsof ECRIS2010, Grenoble, France, p153-155.

Non-patent document 3: winkelmann et al, INTERRATION OFA THIRD ION SOURCE FOR HEAVY ION RADIO THERAPY AT HIT, Proceedings of ECRIS2012, Sydney, Australia, p46-48.

Disclosure of Invention

In facilities in which such a particle beam device is installed, an installation space is generally limited, and therefore miniaturization of the particle beam device is expected. In addition, cost reduction of such a particle beam apparatus is also expected. The invention aims to provide a particle beam device which can realize miniaturization and low cost.

A particle beam apparatus according to the present invention includes an electromagnet capable of introducing each ion beam from a plurality of ion sources having different ion types and capable of selectively emitting one of the ion beams to a downstream side by switching a magnetic field intensity, the electromagnet including: a deflection function of deflecting the ion beam to be emitted to the downstream device toward the downstream device; and an analyzing function for reducing emission of the different types of beams mixed in the ion beam to a downstream device.

The particle beam apparatus of the present invention may include a current measuring device to which one of the ion beams introduced into the electromagnet is incident, the current measuring device being capable of measuring a beam current of the ion beam, and one of the ion beams different from the ion beam directed to the apparatus on the downstream side may be incident. Also, the current measuring device may be provided inside the electromagnet.

Effects of the invention

According to the present invention, a particle beam device that can be reduced in size and cost can be provided.

Drawings

Fig. 1 is a plan view showing a particle beam apparatus.

In fig. 2, (a) is a diagram schematically showing the vicinity of the deflecting electromagnet in the 1 st state, and (b) is a diagram schematically showing the vicinity of the deflecting electromagnet in the 2 nd state.

Fig. 3 is a diagram schematically showing the vicinity of a deflection electromagnet of a particle beam apparatus according to a modification.

In the figure: 1-particle beam device, 11-1 st ion source, 12-2 nd ion source, 15-deflection electromagnet, 17-beam diagnosis device (current measurement device), 19-beam transport system (device on the downstream side), B1-1 st ion beam, B2-2 nd ion beam.

Detailed Description

The particle beam device 1 according to the present invention will be described in detail below with reference to the drawings. Hereinafter, an XYZ rectangular coordinate system may be set as shown in the drawings, and X, Y, Z may be used to explain the positional relationship of each part.

The particle beam device 1 shown in fig. 1 is, for example, a device used for a particle beam therapy device and configured to supply an ion beam to a beam acceleration device 3 of the particle beam therapy device. The beam accelerator 3 is a linear accelerator such as an RFQ (radio-frequency quadrupole). The ion beam supplied from the particle beam device 1 and accelerated by the beam accelerator 3 is transmitted to a main body (not shown) of the particle beam therapy device. In the main body portion, particle beam therapy is performed by irradiating a treatment target patient with the ion beam. The particle Beam apparatus 1 includes two ion sources, i.e., a 1 st ion source 11 and a 2 nd ion source 12, a deflection electromagnet 15, a Beam diagnosis apparatus 17 (current measurement apparatus), and a Beam Transport system (LEBT: Low Energy Beam Transport) 19.

The 1 st ion source 11 and the 2 nd ion source 12 are devices for generating ions, such as ECR ion sources. The 1 st ion source 11 and the 2 nd ion source 12 generate ions different from each other. In the present embodiment, the positive and negative phases of the electric charges of the ions generated by the 1 st ion source 11 and the ions generated by the 2 nd ion source 12 are the sameThe same is true. In this embodiment, C is generated by the 1 st ion source 11⁴⁺2 nd ion source 12 for generating He²⁺(α particle) case will be described as an example.

As shown in fig. 1, the 1 st ion source 11, the deflection electromagnet 15, and the 2 nd ion source 12 are arranged in this order in the Y direction, that is, the deflection electromagnet 15 is disposed so as to be sandwiched between the 1 st ion source 11 and the 2 nd ion source 12 in the Y direction. The 1 st ion source 11 and the 2 nd ion source 12 emit ion beams in directions facing each other, and each ion beam is introduced into a deflection electromagnet 15. Specifically, the 1 st ion source 11 emits an ion beam B1 (hereinafter referred to as "1 st ion beam B1") in the + Y direction, and the 1 st ion beam B1 is incident on the deflection electromagnet 15. The 2 nd ion source 12 emits an ion beam B2 (hereinafter referred to as "2 nd ion beam B2") in the-Y direction, and the 2 nd ion beam B2 is incident on the deflection electromagnet 15. Here, the 1 st ion source 11 and the 2 nd ion source 12 operate simultaneously, and both the 1 st ion beam B1 and the 2 nd ion beam B2 are incident on the deflection electromagnet 15 simultaneously.

Further, from the 1 st ion source 11 to the deflecting electromagnet 15, it is not necessary to provide a beam converging device that converges the 1 st ion beam B1 by a magnetic field. Therefore, the beam emitting nozzle 11a of the 1 st ion source 11 is directly connected to the frame 15h of the deflection electromagnet 15. Similarly, the beam discharge nozzle 12a of the 2 nd ion source 12 is directly connected to the frame 15h of the deflection electromagnet 15 without providing a beam converging device for converging the 2 nd ion beam B2 by a magnetic field between the 2 nd ion source 12 and the deflection electromagnet 15.

The deflection electromagnet 15 includes a pair of magnetic poles 15a and 15b facing each other with a gap therebetween in the Z direction, and a frame 15h that houses the magnetic poles 15a and 15b and is evacuated inside. In the deflection electromagnet 15, a current is supplied to a coil (not shown) of the magnetic pole 15a and a coil (not shown) of the magnetic pole 15b, whereby a magnetic field is formed in a gap between the magnetic pole 15a and the magnetic pole 15 b. The 1 st ion beam B1 and the 2 nd ion beam B2 are introduced into the gap between the magnetic pole 15a and the magnetic pole 15B, and are deflected by passing through the magnetic field. By appropriately adjusting the magnetic field strength of the deflection electromagnet 15 (the magnetic field strength between the magnetic pole 15a and the magnetic pole 15B), one of the 1 st ion beam B1 and the 2 nd ion beam B2 is deflected toward the beam transport system 19, which is a downstream device, and the other is deflected toward the beam diagnosis device 17 (see fig. 2a and 2B).

As shown in fig. 2 (a) and 2 (b), the magnetic pole 15a and the magnetic pole 15b of the deflection electromagnet 15 have the same shape and overlap in the Z direction. The magnetic poles 15a, 15b have hexagonal shapes when viewed from the Z direction, and 4 of 6 sides of the hexagonal shape have corresponding edges 16p, 16q, 16r, 16 s. The 1 st ion beam B1 is introduced into the deflecting electromagnet 15 across the edge 16p, and the 2 nd ion beam B2 is introduced into the deflecting electromagnet 15 across the edge 16 q. One of the 1 st ion beam B1 and the 2 nd ion beam B2 deflected toward the beam transport system 19 is emitted from the deflection electromagnet 15 across the edge 16r, and the other deflected toward the beam diagnosis apparatus 17 is emitted from the deflection electromagnet 15 across the edge 16 s. The edges 16r, 16s are edges extending in the Y direction. The edge 16p is inclined with respect to the X direction, and the 1 st ion beam B1 introduced into the deflecting electromagnet 15 obliquely crosses the edge 16 p. Similarly, the edge 16q is also inclined with respect to the X direction, and the 2 nd ion beam B2 introduced into the deflecting electromagnet 15 obliquely crosses the edge 16 q. In this way, the 1 st ion beam B1 and the 2 nd ion beam B2 obliquely traverse the edges 16p, 16q of the deflecting electromagnet 15, and the 1 st ion beam B1 and the 2 nd ion beam B2 converge.

As shown in fig. 1, the beam diagnosis device 17, the deflection electromagnet 15, and the beam transport system 19 are arranged in the order of the X direction, that is, the deflection electromagnet 15 is disposed so as to be sandwiched between the beam diagnosis device 17 and the beam transport system 19 in the X direction. The beam transport system 19 transports the ion beam (one of the 1 st ion beam B1 or the 2 nd ion beam B2) emitted from the deflection electromagnet 15 in the + X direction to the beam acceleration device 3. The beam transport system 19 is constituted to include three electrostatic quadrupole electromagnets 19a which converge the ion beam.

An ion beam (the other of the 1 st ion beam B1 or the 2 nd ion beam B2) emitted from the deflection electromagnet 15 in the-X direction is incident on the beam diagnosing apparatus 17, and the beam current of the ion beam is measured by the beam diagnosing apparatus 17. In addition, the beam diagnostic apparatus 17 may also measure the beam distribution of the ion beam.

In the particle beam apparatus 1 of the above-described structure, any desired one of the 1 st ion beam B1 or the 2 nd ion beam B2 can be selectively supplied to the beam accelerating device 3 for particle beam therapy. A mechanism for switching between the state of the particle beam apparatus 1 that supplies the 1 st ion beam B1 to the beam accelerator 3 (hereinafter referred to as "1 st state") and the state of the particle beam apparatus 1 that supplies the 2 nd ion beam B2 (hereinafter referred to as "2 nd state") in this manner will be described below. Fig. 2 (a) is a diagram schematically showing the vicinity of the deflection electromagnet 15 in the 1 st state of the particle beam device 1, and fig. 2 (b) is a diagram schematically showing the vicinity of the deflection electromagnet 15 in the 2 nd state of the particle beam device 1.

(1 st state)

As shown in fig. 2 (a), in the 1 st state, the 1 st ion beam B1 is emitted from the beam emitting nozzle 11a of the 1 st ion source 11 in the + Y direction and introduced into the deflection electromagnet 15. Then, the 1 st ion beam B1 is bent by the lorentz force in the direction orthogonal to the traveling direction of the magnetic field of the deflection electromagnet 15, and finally exits from the deflection electromagnet 15 in the + X direction to be emitted to the beam transport system 19 (deflection function of the deflection electromagnet 15).

The direction and curvature of the bending of the 1 st ion beam B1 as described above depend on the magnetic field strength of the deflection electromagnet 15 (magnetic field strength between the magnetic pole 15a and the magnetic pole 15B), and therefore the 1 st ion beam B1 can be emitted to the beam transport system 19 by appropriately setting the magnetic field strength of the deflection electromagnet 15. That is, the magnetic field strength was set to 1 st ion beam B1 (C)⁴⁺Beam) may be deflected by 90 ° toward the beam transport system 19 side in the deflection electromagnet 15. In addition, the 1 st ion beam B1 incident to the beam transport system 19 passes through the beam accelerating device 3 as described above for particle beam therapy.

On the other hand, in the 1 st state, the 2 nd ion beam B2 is emitted in the-Y direction from the beam emitting nozzle 12a of the 2 nd ion source 12 and introduced into the deflection electromagnet 15. Then, the 2 nd ion beam B2 is bent by the lorentz force in the direction orthogonal to the traveling direction of the magnetic field of the deflecting electromagnet 15, and finally exits from the deflecting electromagnet 15 in the-X direction to be emitted to the beam diagnostic apparatus 17. In the beam diagnosis apparatus 17, the beam current of the 2 nd ion beam B2 is measured.

(2 nd state)

As shown in fig. 2 (B), in the 2 nd state, the 1 st ion beam B1 and the 2 nd ion beam B2 are subjected to the lorentz force opposite to the 1 st state, the 2 nd ion beam B2 is emitted to the beam transport system 19, and the 1 st ion beam B1 is emitted to the beam diagnosis apparatus 17. The 2 nd ion beam B2 incident to the beam transport system 19 passes through the beam acceleration device 3 for particle beam therapy as described above, and in the beam diagnosis device 17, the beam current of the 1 st ion beam B1 is measured. To realize this 2 nd state, the magnetic field strength of the deflecting electromagnet 15 is set to the 2 nd ion beam B2 (He)²⁺Beam) may be deflected by 90 ° toward the beam transport system 19 side in the deflection electromagnet 15.

(switching between the 1 st State and the 2 nd State)

Switching between the 1 st state and the 2 nd state as described above can be performed by switching the magnetic field strength of deflecting electromagnet 15. The switching of the magnetic field strength includes reversing the polarity of the magnetic poles 15a and 15 b. Specifically, such switching of the magnetic field strength of the deflection electromagnet 15 is realized by switching the current supplied to the coil (not shown) of the magnetic pole 15a and the coil (not shown) of the magnetic pole 15 b.

(analysis function of deflection electromagnet 15)

The deflecting electromagnet 15 has a deflecting function as described above, and in addition, has an analyzing function. The analysis function is a function of reducing the emission of different types of beams mixed in the ion beam to be transmitted to the beam transmission system 19 toward the beam transmission system 19. For example, in the 1 st ion source 11, the desired C is removed⁴⁺In addition to the beam, C is also generated²⁺Beam, C³⁺Beam, C⁵⁺Beams of different kinds such as nitrogen ion beam, oxygen ion beam, hydrogen ion beam, and C⁴⁺The beams are guided together into deflection electromagnet 15.

In the 1 st state, the magnetic field strength of the deflecting electromagnet 15 is set to C as described above⁴⁺The beam is deflected 90 to the beam delivery system 19 side. At this field strength, the different types of beams as described above differ in mass and charge by C⁴⁺The different curvatures of the beam are curved and,therefore, the beam hardly enters the beam transport system 19 by colliding with the frame 15h of the deflection electromagnet 15 or the like. By performing this analysis function by deflecting the electromagnet 15, the different kinds of beams transmitted to the beam accelerator 3 are reduced. Furthermore, since the deflection electromagnet 15 performs an analysis function, the 1 st ion source 11 and the deflection electromagnet 15 can be directly connected without providing a separate device (for example, another deflection electromagnet) having an analysis function between the 1 st ion source 11 and the deflection electromagnet 15.

Here, the analysis function performed in the 1 st state is described as an example, but the same analysis function is performed in the 2 nd state. That is, in the 2 nd ion source 12, He is desirably removed²⁺In addition to the beam, different kinds of beams such as nitrogen ion beam, oxygen ion beam, and hydrogen ion beam are generated, and in the 2 nd state, these different kinds of beams are mixed with He²⁺As a result of the beam being introduced into the deflection electromagnet 15, the deflection electromagnet 15 performs an analysis function in the same manner as described above, and the number of different types of beams transmitted to the beam accelerator 3 is reduced.

In the 1 st state, the magnetic field strength of the deflection electromagnet 15 causes the 1 st ion beam B1 (C)⁴⁺Beam) is deflected 90 deg., so that at this magnetic field strength, the 2 nd ion beam B2 (He)²⁺Beam) is not 90. Therefore, in the 1 st state, the 2 nd ion beam B2 is not incident on the central position of the beam diagnosis apparatus 17 completely in the-X direction. For the same reason, in the 2 nd state, the 1 st ion beam B1 is not incident completely in the-X direction to the central position of the beam diagnosis apparatus 17. That is, the incident positions of the 2 nd ion beam B2 in the 1 st state and the 1 st ion beam B1 in the 2 nd state to the beam diagnosis apparatus 17 are different in the Y direction. Therefore, the Y-direction size of the beam entrance port of the beam diagnostic apparatus 17 is set so that both the 2 nd ion beam B2 in the 1 st state and the 1 st ion beam B1 in the 2 nd state can enter the beam diagnostic apparatus 17.

As another configuration for causing both the 1 st ion beam B2 in the 1 st state and the 1 st ion beam B1 in the 2 nd state to be incident on the beam diagnostic apparatus 17, the beam diagnostic apparatus 17 may be provided inside the deflection electromagnet 15, as shown in fig. 3. The beam diagnosis device 17 at this time is sandwiched between the magnetic pole 15a and the magnetic pole 15b in the Z direction. In this case, the Y-direction size of the beam entrance port of the beam diagnostic apparatus 17 can be reduced as compared with the configuration of fig. 2.

Next, the operation and effect of the particle beam apparatus 1 will be described.

In the particle beam apparatus 1, the respective ion beams (1 st ion beam B1 and 2 nd ion beam B2) can be introduced from the plurality of ion sources (1 st ion source 11 and 2 nd ion source 12) into the deflection electromagnet 15. Then, by switching the magnetic field density of the deflection electromagnet 15, any one of the plurality of ion beams (1 st ion beam B1 and 2 nd ion beam B2) is selectively emitted to the beam transport system 19. At this time, the deflection electromagnet 15 functions to deflect the ion beam to be emitted to the beam transport system 19 toward the beam transport system 19. The deflection electromagnet 15 also performs an analysis function of reducing emission of a beam of a different type mixed in the ion beam to be emitted to the beam transport system 19 toward the beam transport system 19.

Since the plurality of ion beams having different ion species can be switched and transmitted to the beam transport system 19 by switching the magnetic field density of the deflection electromagnet 15, the plurality of ion beams can be selectively switched and used for the particle beam therapy while sharing the components on the downstream side of the beam from the beam transport system 19. Also, by switching the magnetic field density of the deflecting electromagnet 15, the switching of the ion beam as described above can be performed in a short time. Moreover, the deflection electromagnet 15 performs an analyzing function, and therefore, it is possible to reduce different kinds of beams transmitted to the downstream side by the beam transmission system 19. Further, since the deflection electromagnet 15 performs the analysis function, it is not necessary to separately provide a device having the analysis function (for example, another deflection electromagnet) between the 1 st ion source 11 and the deflection electromagnet 15 and between the 2 nd ion source 12 and the deflection electromagnet 15. Further, the 1 st ion source 11 and the deflection electromagnet 15 are directly connected, and the 2 nd ion source 12 and the deflection electromagnet 15 are directly connected, whereby the particle beam apparatus 1 can be downsized. Further, devices between the 1 st ion source 11 and the deflection electromagnet 15 and between the 2 nd ion source 12 and the deflection electromagnet 15 can be omitted, and cost reduction of the particle beam device 1 can be achieved.

Further, the ion sources (the 1 st ion source 11 and the 2 nd ion source 12) and the deflection electromagnet 15 are directly connected, and a beam transmission path from the ion sources to the deflection electromagnet 15 can be shortened. In this way, since the spread of the ion beam (the 1 st ion beam B1 and the 2 nd ion beam B2) from the ion source to the deflection electromagnet 15 is reduced, the number of beam focusing magnets that need to be provided on the beam propagation path can be reduced, and the cost of the particle beam apparatus 1 can be reduced.

Then, an ion beam different from the ion beam used for the particle beam therapy is incident on the beam diagnosis apparatus 17, and information such as a beam current of the ion beam can be obtained. As such, when the ion beam is not used for the particle beam therapy, the beam current or the like can be measured. Further, in order to obtain information such as the beam current, for example, a mechanical drive mechanism of the insertion/removal beam diagnostic apparatus may be constructed on the trajectory of the ion beam, but the cost of the particle beam apparatus 1 may be reduced by omitting the mechanical drive mechanism.

The present invention can be implemented in various ways, including the above-described embodiments, by implementing various modifications and improvements according to the knowledge of those skilled in the art. Further, the modifications of the embodiments may be configured by using the technical contents described in the above embodiments. The structures of the embodiments may be used in appropriate combinations.

For example, the particle beam apparatus does not necessarily need to include the beam diagnostic apparatus 17, and a beam stopper may be provided instead of the beam diagnostic apparatus 17. In the embodiment, the incident direction of the 1 st ion beam B1 and the incident direction of the 2 nd ion beam B2 that are incident on the deflection electromagnet 15 are opposed to each other, but these incident directions may intersect at a predetermined angle. In the embodiment, the 1 st ion source 11 and the 2 nd ion source 12 are operated simultaneously, but when one ion source is used for the particle beam therapy, the operation of the other ion source may be stopped.

In the embodiment, there are two ion sources (the 1 st ion source 11 and the 2 nd ion source 12) that introduce ion beams into the deflection electromagnet 15, but there may be three or more such ion sources. In the embodiments, the inventionC represents a number of ions of the 1 st ion beam B1 and the 2 nd ion beam B2 processed by the particle beam apparatus 1⁴⁺Beam and He²⁺The beam example has been described, but the beam is not limited to this, and for example, the 1 st ion beam B1 or the 2 nd ion beam B2 may be H⁺、H₂ ⁺、He²⁺、C⁴⁺And the like.