CN115499994A

CN115499994A - Compact beam switching deflection device and application thereof

Info

Publication number: CN115499994A
Application number: CN202211194664.7A
Authority: CN
Inventors: 马力祯; 石健; 彭伟壮; 吴巍; 梅恩铭
Original assignee: Lanzhou Kejin Taiji Corp ltd
Current assignee: Lanzhou Kejin Taiji Corp ltd
Priority date: 2022-09-28
Filing date: 2022-09-28
Publication date: 2022-12-20

Abstract

The invention provides a compact beam switching deflection device and application thereof, and relates to the technical field of ion accelerator equipment. The device comprises a superconducting beam splitter, a multi-channel vacuum chamber and a superconducting combined magnet which are sequentially connected, wherein: the superconducting beam splitter is used for splitting an input beam, the multi-channel vacuum chamber is provided with a plurality of leading-out ports, each leading-out port is connected to one branch beam line pipeline in a flange mode, and at least one branch beam line pipeline is provided with a superconducting combined magnet. The superconducting magnet is adopted to deflect the beam current, so that the maximum field intensity of the deflecting magnet is improved, the deflection radius of the beam current is reduced, and the occupied area is reduced. And moreover, the combined superconducting magnet is adopted, and a four-pole field is compounded to a two-pole field, so that the use of the four-pole magnet is reduced, and the occupied area is further reduced.

Description

Compact beam switching deflection device and application thereof

Technical Field

The invention relates to the technical field of ion accelerator equipment, in particular to a compact beam switching deflection device and application thereof.

Background

The medical ion accelerator is a device which accelerates and constrains ions by utilizing an electromagnetic field, accelerates the ions to higher energy, so that the ions can penetrate through the epidermis of a human body and reach a tumor position to treat tumors. The ion herein refers to an ion from hydrogen to neon in the periodic table, such as proton, helium ion, carbon ion, etc., and usually most commonly proton and carbon ion.

The medical ion accelerator has a series of thresholds of complex research and development technology, large capital investment, complex production and control process, high quality requirement and the like. Generally, the treatment with the beam takes a little time, but before the treatment, a relatively large amount of preparation is needed, such as detecting the position of a tumor with CT, positioning the patient, and so on. If a medical ion accelerator is only provided with one treatment room, much time is wasted on preparation work, and the beam current cannot be well utilized. An accelerator is usually equipped with several treatment rooms so that while one room is preparing the patient, another room can be treating the patient with the beam. To construct multiple treatment rooms, the beam is split so that the beam can be deflected in different directions.

Most of medical ion accelerators in the current market use conventional magnets, and the magnets are large due to the limitation of field intensity, so that the whole equipment is large in space volume, large in occupied area and large in investment amount. Therefore, the development of compact ion therapy devices, the reduction of the occupied area and the reduction of the investment amount become one of the current major consideration and research directions, which is also the development trend of future particle radiotherapy equipment.

Disclosure of Invention

In view of the above problems, the present invention provides a compact beam switching deflection apparatus and applications thereof.

The invention provides a compact beam switching deflection device, which comprises a superconducting beam splitter, a multi-channel vacuum chamber and a superconducting combined magnet which are sequentially connected, wherein: the superconducting beam splitter is used for splitting an input beam, the multi-channel vacuum chamber is provided with a plurality of leading-out ports, each leading-out port is connected to one branch beam line pipeline through a flange, and at least one branch beam line pipeline is provided with a superconducting combined magnet.

According to the embodiment of the invention, a hollow truncated cone-shaped vacuum pipeline is arranged at the inlet of the superconducting beam splitter, and the hollow truncated cone-shaped vacuum pipeline is connected to the main beam flow vacuum pipeline through a flange; the outlet flange of the superconductive beam splitter is connected with the multi-channel vacuum chamber.

According to an embodiment of the invention, the inner diameter of the superconducting beam splitter is larger than the inner diameter of the main beam vacuum conduit.

According to the embodiment of the invention, the multi-channel vacuum chamber comprises a three-channel vacuum chamber which is in a hollow quadrangular prism vacuum box structure.

According to an embodiment of the present invention, the superconducting composite magnet is a composite superconducting magnet formed by winding a four-pole magnet around a coil of a two-pole magnet.

According to an embodiment of the present invention, the breakout harness conduits include a first breakout harness conduit, a second breakout harness conduit, and a third breakout harness conduit, wherein: the first branch beam line pipeline is provided with a combined superconducting magnet and is used for deflecting and focusing the beam current in a first direction; the second branch beam line pipeline is provided with a quadrupole magnet for enabling the beam to pass through linearly; the third branch beam line pipeline is provided with a combined superconducting magnet for deflecting and focusing the beam current in a second direction.

According to the embodiment of the invention, the quadrupole magnet is FODO or triple structure, and the focusing magnetic field and the defocusing magnetic field are alternately arranged.

According to an embodiment of the invention, the device does not exceed 6m in both the length and width directions.

According to the embodiment of the invention, the input beam of the superconducting beam splitter is a convergent beam or a divergent beam; wherein, the field intensity of the quadrupole magnet is adjusted to be non-dispersive beam at the outlet.

The invention also provides application of the compact beam switching deflection device in tumor treatment and industrial irradiation.

Compared with the prior art, the compact beam switching deflection device and the application thereof provided by the invention at least have the following beneficial effects:

(1) The superconducting magnet is adopted to deflect the beam, so that the maximum field intensity of the deflection magnet is improved, and the deflection radius of the beam is reduced, thereby reducing the occupied area;

(2) The combined superconducting magnet is adopted to compound the four-pole field to the two-pole field, so that the use of the four-pole magnet is reduced, and the occupied area is further reduced.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 schematically shows a block diagram of a compact beam switching deflection apparatus according to an embodiment of the present invention;

FIG. 2 schematically illustrates an inlet elevation view, an overall elevation view, and an outlet elevation view of a multi-channel vacuum chamber according to an embodiment of the invention;

FIGS. 3 (a), 3 (b) and 3 (c) are schematic diagrams respectively showing three kinds of trajectory roadmaps of beam current when a magnetic field is changed by the superconducting beam splitter according to the embodiment of the present invention;

FIG. 4 schematically illustrates a layout of three breakout harness conduits in accordance with an embodiment of the present invention;

FIG. 5 is a graph schematically illustrating experimental results of optical parameters of a superconducting beam splitter according to an embodiment of the present invention at a first entrance parameter;

fig. 6 is a graph schematically showing a result of a beam envelope experiment of a superconducting beam splitter according to an embodiment of the present invention;

FIG. 7 is a graph schematically illustrating experimental results of optical parameters of a superconducting beam splitter according to an embodiment of the present invention at a second entrance parameter.

[ description of reference ]

Fig. 1 to 3: 1-a superconducting beam splitter; 2-a multi-channel vacuum chamber; 31-a first flange; 32-a second flange; 33-a third flange;

FIG. 4: 101-superconducting beam splitter; 102-a multi-channel vacuum chamber; 111-a first combined superconducting magnet; 112-second combined superconducting magnet; 121-a first quadrupole magnet; 122-a second quadrupole magnet; 131-third combination superconducting magnet; 132-fourth combination superconducting magnet.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments and the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprises," "comprising," and the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically connected, electrically connected or can communicate with each other; either directly or indirectly through intervening media, either internally or in any other suitable relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It is noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of this specification and should not be interpreted in an idealized or overly formal sense.

There are two main types of magnets in the accelerator, a dipole magnet and a quadrupole magnet. Quadrupole magnets provide a magnetic field with a gradient in the transverse direction (the direction perpendicular to the direction of ion motion) for transverse focusing of the beam stream. The beam current is mainly deflected by a uniform magnetic field provided by a dipolar magnet, and the higher the energy of the ions is, the larger the magnetic field required for deflecting the ions is. For ions with the same energy, the larger the field intensity of the deflecting magnetic field is, the smaller the deflecting radius is, the smaller the required dipolar magnet can be, and the occupied area can be reduced. However, in contrast to superconducting magnets, the maximum value of the magnetic field of conventional magnets is often not made too high, which determines that dipolar magnets cannot be made too small. A conventional magnet typically deflects the beam in only one direction because the field of the conventional magnet is too small and the aperture required to deflect the beam in both directions is very large. So that multiple dipole magnets are needed to deflect the beam at multiple angles.

For a typical carbon ion accelerator, the radius of the dipole magnet for deflecting carbon ions is generally about 4m, and two dipole magnets with a radius of 4m and a deflection angle of 45 ° are required to deflect carbon ions by 90 °. When deflecting carbon ions, in order to ensure that the ions keep converging and do not scatter in the moving process, a plurality of quadrupole magnets are also needed, so that a larger space is needed.

In short, the conventional beam splitter usually requires a relatively large number of dipole magnets and quadrupole magnets if the beam is to be deflected in two different directions. Moreover, because the field intensity of the conventional magnet is not large, the beam current can not be controlled to deflect in different directions in one magnet, and the length of the device can be too long. Therefore, the existing beam deflection device has the main defects of more used magnets and larger occupied area.

In view of this, the present invention provides a compact beam switching deflection apparatus and an application thereof, so as to provide a solution for solving the problem of distribution of beams to different treatment terminals in the medical ion treatment technology.

Fig. 1 schematically shows a block diagram of a compact beam switching deflection apparatus according to an embodiment of the present invention.

As shown in fig. 1, the compact beam switching deflector according to this embodiment includes a superconducting beam splitter 1, a multi-channel vacuum chamber 2, and a superconducting combined magnet, which are connected in this order. The superconducting beam splitter 1 is used for splitting an input beam, the multi-channel vacuum chamber 2 is provided with a plurality of leading-out ports, each leading-out port is connected to one branch beam line pipeline in a flange mode, and at least one branch beam line pipeline is provided with a superconducting combined magnet.

Through the embodiment, the superconducting magnet is adopted to deflect the beam current, and the field intensity which can be reached by the superconducting magnet is more than twice of that of a conventional magnet, so that the size of the magnet can be greatly reduced, the occupied area is reduced, and the cost is reduced.

The superconducting beam splitter 1 deflects the input beam current by different angles under the action of a self variable magnetic field, and splits the input beam current along different angles, so that the good field area of the superconducting beam splitter 1 is larger than that of a conventional magnet.

In the embodiment of the invention, the inlet of the superconducting beam splitter 1 is provided with a hollow truncated cone-shaped vacuum pipeline, and the hollow truncated cone-shaped vacuum pipeline is connected to the main beam flow vacuum pipeline through a flange.

Further, the inner diameter of the superconducting beam splitter 1 is larger than that of the main beam vacuum pipeline. Thus, the superconducting beam splitter 1 acts as a large-aperture vacuum conduit as compared to the main beam flow vacuum conduit. The main beam current vacuum pipeline is transited to the inlet of the superconducting beam splitter 1 through the hollow round table-shaped vacuum pipeline and the first flange 31 with the small aperture in sequence.

In the embodiment of the invention, the outlet flange of the superconducting beam splitter 1 is connected with the multi-channel vacuum chamber 2. Specifically, the outlet of the superconducting beam splitter 1 is connected to the multi-channel vacuum chamber 2 through a second flange 32 with a large aperture, and a plurality of outlets of the multi-channel vacuum chamber 2 are connected with branch beam line pipelines in the corresponding direction of the rear stage through a third flange 33 with a small aperture.

It should be noted that the shape structure of the vacuum chamber of the multi-channel vacuum chamber 2 itself and the number of the outlet channels can be flexibly designed according to the number of beam deflection directions and the specific angle determined by the superconducting beam splitter 1, as long as it is ensured that the beam is not shielded by the inner wall of the multi-channel vacuum chamber 2, and the invention is not limited in particular.

FIG. 2 schematically illustrates an inlet elevation view, an overall elevation view, and an outlet elevation view of a multi-channel vacuum chamber according to an embodiment of the invention.

As shown in fig. 2, in some embodiments of the present invention, the multi-channel vacuum chamber 2 comprises a three-channel vacuum chamber, which is a hollow quadrangular prism vacuum box structure, and is as compact as possible under the premise of being able to enclose the beam.

Fig. 3 (a), 3 (b) and 3 (c) schematically show three kinds of trajectory roadmaps of the beam current when the magnetic field changes in the superconducting beam splitter according to the embodiment of the present invention, respectively.

The main working principle of the compact beam switching deflection device explained above lies in that: first, when the coil of the superconducting beam splitter 1 is not energized, there will be no dipole magnetic field inside the beam splitter, and the ions will continue to move along a straight line without deflection, as shown in fig. 3 (a), the central straight line represents the trajectory of the beam current. Secondly, when the coil of the superconducting beam splitter 1 is energized, a dipolar magnetic field is generated inside the beam splitter to deflect the charged particles, and when the generated magnetic field is in a direction perpendicular to the plane of the paper and facing inwards, the ions are subjected to an upward force according to the lorentz force equation, and are deflected upwards, as shown in fig. 3 (b), and the central trajectory is deflected upwards. Then, when a current in the opposite direction is passed through the coil of the superconducting beam splitter 1, a magnetic field is generated which is perpendicular to the outside of the paper surface, and this magnetic field generates a downward force on the ions, so that the ions are deflected downward, as shown in fig. 3 (c), and the central trajectory is deflected downward.

When the particles are deflected by the superconducting beam splitter 1, dispersion is introduced due to the difference in momentum of the particles, making the central orbitals of different particles different. In order to eliminate dispersion, a superconducting combined magnet is required to be connected to a branch beam line pipeline which is subsequent to the upper deflection direction and the lower deflection direction.

In order to save space, the superconducting combined magnet is a combined superconducting magnet formed by winding a four-pole magnet around a coil of a two-pole magnet. In addition, in order to focus the beams in the horizontal direction and the vertical direction at the same time, the quadrupole magnet may be of FODO or Triplet structure, and the focusing and defocusing magnetic fields are alternately arranged.

It should be noted that parameters of the beam entering the superconducting beam splitter 1 are uncertain, and various conditions should be considered in the design. In designing the superconducting beam splitter 1, the following can be considered: the beam current is just at the beam waist position when entering the superconducting beam splitter 1; the beam current will converge when entering the superconducting beam splitter 1; the beam current is a divergent beam when entering the superconducting beam splitter 1; the dispersion of the beam upon entering the superconducting beam splitter 1 is not zero. In the above cases, the matching of beam parameters can be realized by adjusting the size of the quadrupole magnet on the combined superconducting magnet.

Based on the above-described operating principle, fig. 4 schematically shows the layout of three types of branching harness conduits according to an embodiment of the present invention.

As shown in fig. 4, in some embodiments of the present invention, the breakout harness conduits include a first breakout harness conduit, a second breakout harness conduit, and a third breakout harness conduit, wherein: the first branch beam line pipeline is provided with a combined superconducting magnet and is used for deflecting and focusing the beam current in a first direction; the second branch beam line pipeline is provided with a quadrupole magnet for enabling the beam to pass through linearly; the third branch beam line pipeline is provided with a combined superconducting magnet for deflecting and focusing the beam current in a second direction.

In particular, the combined superconducting magnet is provided on the first branch beamline conduit for the purpose of further deflecting and focusing the beam stream. The quadrupole magnet provided in the second branch beam line pipe corresponds to the case where no magnetic field is applied to the superconducting beam splitter 1. The combined superconducting magnet provided on the third branch beamline conduit is similar to the first branch beamline conduit, but differs therefrom in the arrangement of the deflection direction. The second direction may be different from the first direction, and preferably, the second direction and the first direction may be symmetrical to each other along a linear direction of the input beam.

With the arrangement shown in fig. 4, the length direction and the width direction of the whole compact beam current switching deflector do not exceed 6m. If a conventional magnet is used to achieve the same deflection effect on the beam, it is generally required to be about 10m in the longitudinal direction and about 13m in the width direction. Therefore, compared with the conventional beam deflection scheme, the beam deflection method has the advantages that the occupied area is reduced by more than 2/3, a lot of space is saved, the use of four-pole magnets is reduced, and the manufacturing cost is reduced.

The beam optics and beam envelope of the example under the layout shown in fig. 4 are obtained in fig. 5 and 6, respectively. Fig. 5 is a graph schematically showing experimental results of optical parameters of a superconducting beam splitter according to an embodiment of the present invention at a first entrance parameter. Fig. 6 is a graph schematically showing a result of a beam envelope experiment of the superconducting beam splitter according to the embodiment of the present invention.

As can be seen from fig. 5, the beam current is matched to a dispersion-free beam current at the end of the superconducting beam splitter 1. Meanwhile, as can be seen from fig. 6, the envelope of the beam current is very small, and is basically below 15mm, so that the aperture of the combined superconducting magnet does not need to be very large, and the processing difficulty can be further reduced.

Further, in order to make the application of the superconducting beam splitter 1 more extensive, the optical parameters at the entrance of the superconducting beam splitter 1 are changed, as shown in fig. 7, the input beam of the superconducting beam splitter 1 is a converged beam, and the dispersion value is not zero. Wherein, the field intensity of the quadrupole magnet is adjusted to be non-dispersive beam at the outlet. In this case, the optical re-matching to the actually required parameters can be achieved by changing the magnitude of the quadrupole magnet field component on the combined superconducting magnet.

It should be noted that, when the input beam of the superconducting beam splitter 1 is a divergent beam, the requirement can be satisfied by adjusting the quadrupole field, and details are not described here.

According to the embodiment of the invention, the superconducting magnet is adopted to deflect the beam, so that the maximum field intensity of the deflecting magnet is improved, the deflection radius of the beam is reduced, and the occupied area is reduced. And moreover, the combined superconducting magnet is adopted, and a four-pole field is compounded to a two-pole field, so that the use of the four-pole magnet is reduced, and the occupied area is further reduced.

Based on the above disclosure, another embodiment of the present invention provides an application of the above compact beam switching deflection apparatus in tumor therapy and industrial irradiation. For example, the compact beam switching deflection device can be applied to a medical particle accelerator, an isotope production accelerator, a nuclear track membrane production accelerator, a material irradiation accelerator, a muon generation accelerator, a neutron source and the like, and can provide beams for a plurality of different application terminals at the same time.

In summary, embodiments of the present invention provide a compact beam switching deflection apparatus and an application thereof, where the apparatus includes a large-aperture superconducting beam splitter, a multi-channel vacuum chamber, and a subsequent combined superconducting magnet in sequence. By using the device, the beam current can be rapidly switched and deflected to different treatment terminals according to treatment requirements. Meanwhile, the device has a compact structure, can reduce the traditional high-energy beam line multi-terminal beam deflection structure by more than half, and effectively reduces the device cost.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Throughout the drawings, like elements are represented by like or similar reference numerals. And conventional structures or constructions will be omitted when they may obscure the understanding of the present invention. And the shapes, sizes and positional relationships of the components in the drawings do not reflect the actual sizes, proportions and actual positional relationships.

Similarly, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various disclosed aspects. Reference to the description of the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. Furthermore, the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. Unless otherwise specified, the expressions "about", "substantially" and "about" mean within 10%, preferably within 5%.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a compact beam switches deflection device which characterized in that, includes superconductive beam splitter, multichannel vacuum chamber and superconductive combination magnet that connects gradually, wherein:

the superconducting beam splitter is used for splitting an input beam, the multi-channel vacuum chamber is provided with a plurality of leading-out ports, each leading-out port is connected to one branch beam line pipeline in a flange mode, and the superconducting combined magnet is arranged on at least one branch beam line pipeline.

2. The compact beam switching deflection device according to claim 1, wherein an inlet of the superconducting beam splitter is provided with a hollow truncated cone-shaped vacuum pipe, and the hollow truncated cone-shaped vacuum pipe is flange-connected to a main beam vacuum pipe;

and an outlet flange of the superconducting beam splitter is connected with the multi-channel vacuum chamber.

3. The compact beam switching deflector of claim 2, wherein the superconducting beam splitter has an inner diameter greater than an inner diameter of the main beam vacuum conduit.

4. The compact beam switching deflection device according to claim 1, wherein the multi-channel vacuum chamber comprises a three-channel vacuum chamber in the form of a hollow quadrangular prism vacuum box.

5. The compact beam switching deflection device according to claim 1, wherein the superconducting combination magnet is a combination-type superconducting magnet formed by winding a four-pole magnet around a coil of a two-pole magnet.

6. The compact beam current switching deflector of claim 5, wherein the breakout harness conduits comprise a first breakout harness conduit, a second breakout harness conduit, and a third breakout harness conduit, wherein:

the first branch beam line pipeline is provided with a combined superconducting magnet and is used for deflecting and focusing beam current in a first direction;

the second branch beam line pipeline is provided with a quadrupole magnet for enabling the beam to pass through linearly;

and the third branch beam line pipeline is provided with a combined superconducting magnet for deflecting and focusing the beam current in a second direction.

7. The compact beam switching deflector according to claim 5, wherein the quadrupole magnet is FODO or triple structure, and the focusing and defocusing magnetic fields are alternately arranged.

8. The compact beam switching deflector of claim 1, wherein the deflector does not exceed 6m in both the length and width directions.

9. The compact beam switching deflection device of claim 5, wherein the input beam of the superconducting beam splitter is a converging beam or a diverging beam;

and adjusting the field intensity of the quadrupole magnet to be a dispersion-free beam at the outlet.

10. Use of a compact beam switching deflector device according to any of claims 1-9 for tumor therapy and industrial irradiation.