阅读说明：本技术 一种普惠型的轻离子肿瘤治疗装置 (Popular type light ion tumor treatment device ) 是由 詹文龙 杨建成 夏佳文 赵红卫 徐瑚珊 胡正国 马力祯 石健 杨磊 申国栋 吴巍 于 2020-12-15 设计创作，主要内容包括：本发明涉及一种普惠型的轻离子肿瘤治疗装置,包括：离子源,离子源包壳体以及设置在所述壳体内的进气管道、蒸发炉和波导管；直线注入器,直线注入器的输入端通过低能束运线与离子源的输出端连接,直线注入器包括加速腔以及套设在加速腔外部的磁聚焦元件；同步加速器,同步加速器的输入端通过中能束运线与直线注入器的输出端连接,同步加速器的束流输入端设置有注入切割磁铁、注入凸轨磁铁和注入静电偏转板；治疗终端,治疗终端通过高能束运线与同步加速器连接。本发明装置不仅可以利用质子进行全身治疗,同时还可以使用～3He、～4He、～7Li等轻离子束流进行浅层(≤8cm)肿瘤治疗。(The invention relates to a general type light ion tumor treatment device, which comprises: the ion source comprises a shell, and an air inlet pipeline, an evaporation furnace and a waveguide tube which are arranged in the shell; the input end of the linear injector is connected with the output end of the ion source through a low-energy beam transport line, and the linear injector comprises an acceleration cavity and a magnetic focusing element sleeved outside the acceleration cavity; the input end of the synchrotron is connected with the output end of the linear injector through an intermediate energy beam transport line, and the beam input end of the synchrotron is provided with an injection cutting magnet, an injection convex rail magnet and an injection static deflection plate; and the treatment terminal is connected with the synchrotron through a high-energy beam transport line. The device of the invention can not only utilize protons for whole body treatment, but also can be used 3 He、 4 He、 7 And (3) carrying out superficial layer (less than or equal to 8cm) tumor treatment by using light ion beams such as Li and the like.)

1. A general type of light ion tumor treatment device, characterized in that:

through the combination of a compact ECR ion source, a high-working-frequency linear injector, a variable-convex-track synchrotron and a treatment terminal, not only protons but also treatment can be accelerated³He、⁴He、⁷Li and light ions with atomic numbers of 4-20, so that the accelerator can not only realize the treatment of conventional protons adapting to cancer types, but also effectively cover shallow tumors;

the ion source comprises a shell (11), and a gas inlet pipeline (1), an evaporation furnace (2) and a waveguide tube (3) which are arranged in the shell (11), wherein the gas inlet pipeline (1) is used for conveying gas into the shell (11), the evaporation furnace (2) is used for evaporating solid molecules or atoms to generate gas, the waveguide tube (3) is used for feeding microwave power into the shell (11), and electrons collide with the gas molecules under the combined action of a magnetic field and microwaves to generate light ion beam current;

the linear implanter is characterized in that the input end of the linear implanter is connected with the leading-out end of the ion source through a low-energy beam transport line, the linear implanter comprises an accelerating cavity (9) and a magnetic focusing element (10) sleeved outside the accelerating cavity (9), and the magnetic focusing element (10) is used for generating a longitudinal magnetic field and providing an additional focusing force for light ion beam current;

the input end of the synchrotron is connected with the output end of the linear injector through an intermediate energy beam transport line, the beam input end of the synchrotron is provided with injection convex rail magnets (12-1-12-4) and an injection static deflection plate, the injection convex rail magnets (12-1-12-4) are used for raising a circulating beam balance track, so that the beam deflected by the injection static deflection plate enters the annular acceptance degree and gradually descends in the injection process, the loss of the returned beam hitting the injection static deflection plate is avoided, meanwhile, the smearing and filling of the beam in a phase space are completed, after the injection is completed, the light ion beam is accelerated to reach the energy required by treatment, and is led out to the high energy beam transport line through an extraction system;

and the treatment terminal is connected with the synchrotron through the high-energy beam transport line and is used for enabling the light ion beam to accurately reach the position of the tumor cell.

2. The light ion tumor treatment device according to claim 1, wherein an injection end magnetic ring (5) and a leading-out end magnetic ring (7) are respectively arranged at the injection end and the leading-out end of the housing (11), a hexapole magnetic ring (6) is arranged between the injection end magnetic ring (5) and the leading-out end magnetic ring (7), the injection end magnetic ring (5), the hexapole magnetic ring (6) and the leading-out end magnetic ring (7) jointly define an arc cavity, the air inlet pipe (1), the evaporation furnace (2), the waveguide tube (3) and the injection soft iron (4) are arranged in the arc cavity close to the injection end of the housing (11), and an extraction electrode (8) is arranged in the arc cavity close to the leading-out end of the housing (11) and used for extracting light ion beams out of the ion source.

3. The light ion tumor therapy device according to claim 1, wherein the longitudinal electric field generated by the acceleration chamber (9) provides an acceleration effect for the light ion beam, the generated transverse electric field provides a partial focusing effect for the light ion beam, and the magnetic focusing element (10) sleeved outside the acceleration chamber (9) provides another partial focusing effect for the light ion beam.

4. The light ion tumor treatment device according to claim 1, wherein the beam input end of the synchrotron is further provided with an injection cutting magnet for deflecting the beam close to the injection rail, and the injection electrostatic deflection plate is used for further deflecting the beam transmitted by the injection cutting iron to within the beam acceptance.

5. A method for operating the light ion tumor therapy device according to any one of claims 1 to 4, comprising the steps of:

a, when light ions needing gas ionization are treated, gas is conveyed into the arc cavity through the gas inlet pipeline (1), microwave power is fed into the arc cavity through the waveguide tube (3), electrons generate cyclotron resonance under the combined action of a magnetic field and microwaves, the speed is increased continuously, after the electrons collide with gas molecules, outer-layer electrons of the gas molecules are stripped to generate light ions, and the light ions are led out under the action of the leading-out electrode (8) and conveyed into the linear injector through the low-energy beam transport line;

b, when the solid molecules or atoms are required to be ionized to light ions for treatment, the solid molecules or atoms are evaporated through the evaporation furnace (2) to generate steam and are sent into the arc cavity, microwave power is fed into the arc cavity through the waveguide tube (3), electrons generate cyclotron resonance under the combined action of a magnetic field and microwaves, the speed is increased continuously, after the electrons collide with the steam, the outer electrons of the steam molecules or atoms are stripped to generate charged light ions, and the charged light ions are led out under the action of the leading-out electrode (8) and are conveyed into the linear injector through the low-energy beam transport line;

c, light ion beams transmitted by the low-energy beam transport line are injected into the accelerating cavity (9) in a radial matching mode, a longitudinal high-frequency electric field generated by the accelerating cavity (9) shapes, bunches and accelerates the light ion beams, a transverse electric field and a focusing magnetic field generated by the magnetic focusing element (10) focus the light ion beams, the light ion beams gradually reach the energy required by the injection of the synchrotron, and are conveyed into the synchrotron through the medium-energy beam transport line after being led out from the outlet of the linear injector;

d, after light ions are conveyed to the synchrotron, beam current is deflected by the injection cutting magnet and the injection static deflection plate, the beam current is gradually close to the synchrotron, the included angle between the beam current and a central track is gradually reduced, and the beam current reaches an injection preparation state, at the moment, the injection convex track magnet (12-1-12-4) is started, the central track of the synchrotron is locally protruded, and the injected beam current enters the acceptance of the synchrotron; in the injection process, the local convex rail magnets (12-1-12-4) gradually descend, injected beam current is smeared from inside to outside in a horizontal phase space, and the beam current gradually fills the whole acceptance;

and e, after the injection is finished, accelerating the light ion beam to reach the energy required by treatment, transmitting the light ion beam to the high-energy beam line through the extraction system, and distributing the light ion beam to the treatment terminal through the high-energy beam line.

Technical Field

The invention relates to a general type light ion tumor treatment device, and belongs to the technical field of medical equipment.

Background

Because the irradiation of the ion beam to the organism has reversed depth dose distribution and higher relative biological effect, the damage to normal cells can be better avoided while tumor cells are killed, so that the ion cancer therapy becomes an international advanced and effective cancer radiotherapy method. The ions most commonly used in ion therapy of cancer at present are protons and carbon ions, which have advantages and disadvantages in terms of indication and cost.

The carbon ion linear energy density, the relative biological effect and the side scattering have more remarkable advantages, can generate DNA Double Strand Break (DSB) which is difficult to repair, and is usually used as the optimal choice for treating cancer, but because the energy of a carbon ion accelerator is required to be more than 430MeV/u, the magnetic rigidity is larger, the occupied area of the device is large, and the investment scale is higher; the proton treatment device needs low magnetic rigidity, generally adopts a fixed energy accelerator, has low cost, relatively mature technology, small occupied area and low market popularization difficulty, but has low proton beam energy transfer linear density (LET), can only break a DNA single chain and has slightly poor treatment effect on tumors.

If it is possible to simultaneously provide ions having biological effects close to those of carbon ions within the range of the size and acceleration capability of a proton accelerator, e.g.) "³He”、“⁴He "or"⁷Li' can be used for treating conventional proton-adaptive cancers, and can also effectively cover superficial tumors such as melanoma, head and neck tumors of five sense organs, prostate tumors, breast tumors and the like, thereby achieving the purpose of one machine with multiple purposes.

Disclosure of Invention

Aiming at the problems, the invention provides a general light-ion tumor treatment device, which adopts the combination of a miniature high-charge state full-permanent-magnet ECR ion source, a high-working-frequency linear injector with an external magnetic focusing structure, a variable-convex-track synchrotron and a treatment terminal, improves from the aspects of beam supply type, ion source structure, linear injector structure, injection method and the like, widens the treatment range of cancer types, and reduces the occupied area and the manufacturing cost of the system.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a general type light ion tumor treatment device, which comprises the following components:

through the combination of a compact ECR ion source, a high-working-frequency linear injector, a variable-convex-track synchrotron and a treatment terminal, not only protons but also treatment can be accelerated³He、⁴He、⁷Li and light ions with atomic numbers of 4-20, so that the accelerator can not only realize the treatment of conventional protons adapting to cancer types, but also effectively cover shallow tumors;

the ion source comprises a shell, and an air inlet pipeline, an evaporation furnace and a waveguide tube which are arranged in the shell, wherein the air inlet pipeline is used for conveying gas into the shell, the evaporation furnace is used for evaporating solid molecules or atoms to generate gas, the waveguide tube is used for feeding microwave power into the shell, and electrons collide with gas molecules under the combined action of a magnetic field and microwaves to generate light ion beam current;

the linear injector is connected with the leading-out end of the ion source through a low-energy beam transport line and comprises an acceleration cavity and a magnetic focusing element sleeved outside the acceleration cavity, and the magnetic focusing element is used for generating a longitudinal magnetic field and providing extra focusing force for light ion beam current;

the input end of the synchrotron is connected with the output end of the linear injector through an intermediate energy beam transport line, the beam input end of the synchrotron is provided with an injection convex rail magnet and an injection static deflection plate, the injection convex rail magnet is used for raising a circulating beam balance track, so that the beam deflected by the injection static deflection plate enters the annular acceptance degree and gradually descends in the injection process, the loss caused by the fact that the returned beam hits the injection static deflection plate is avoided, meanwhile, the smearing and filling of the beam in a phase space are completed, after the injection is completed, the light ion beam is accelerated to reach the energy required by treatment, and the light ion beam is led out to the high energy beam transport line through an extraction system;

and the treatment terminal is connected with the synchrotron through the high-energy beam transport line and is used for enabling the light ion beam to accurately reach the position of the tumor cell.

The light ion tumor treatment device is characterized in that an injection end magnetic ring and a leading-out end magnetic ring are respectively arranged at an injection end and a leading-out end of the shell, a hexapole magnetic ring is arranged between the injection end magnetic ring and the leading-out end magnetic ring, an arc cavity is defined by the injection end magnetic ring, the hexapole magnetic ring and the leading-out end magnetic ring together, the air inlet pipeline, the evaporation furnace, the waveguide tube and the injection soft iron are arranged in the arc cavity close to the injection end of the shell, and a leading-out electrode is arranged in the arc cavity close to the leading-out end of the shell and used for leading light ion beams out of the ion source.

Preferably, the light ion tumor treatment device is characterized in that a longitudinal electric field generated by the acceleration cavity provides an acceleration effect for the light ion beam, a generated transverse electric field provides a partial focusing effect for the light ion beam, and the magnetic focusing element sleeved outside the acceleration cavity provides another partial focusing effect for the light ion beam.

In the light ion tumor treatment device, preferably, a beam input end of the synchrotron is further provided with an injection cutting magnet, the injection cutting magnet is used for deflecting the beam to be close to an injection track, and the injection electrostatic deflection plate is used for further deflecting the beam transmitted by the injection cutting magnet to be within a beam acceptance.

In a second aspect, the present invention provides a method for operating the above-mentioned conventional light ion tumor therapy device, comprising the following steps:

a when light ions needing gas ionization are treated, gas is conveyed into the arc cavity through the gas inlet pipeline, microwave power is fed into the arc cavity through the waveguide tube, electrons generate cyclotron resonance under the combined action of a magnetic field and microwaves, the speed is increased continuously, after the electrons collide with gas molecules, outer layer electrons of the gas molecules are stripped, light ions are generated, the light ions are led out under the action of the leading-out electrode and conveyed into the linear injector through the low-energy beam transport line;

b, when the solid molecules or atoms are required to be ionized to light ions for treatment, evaporating the solid molecules or atoms through the evaporation furnace to generate steam and sending the steam into the arc cavity, feeding microwave power into the arc cavity by using the waveguide tube, generating cyclotron resonance by electrons under the combined action of a magnetic field and microwaves at an increasing speed, stripping outer-layer electrons of the steam molecules or atoms after colliding with the steam to generate charged light ions, leading the charged light ions out under the action of the leading-out electrode, and conveying the charged light ions into the linear injector through the low-energy beam transport line;

c, injecting the light ion beam transmitted by the low-energy beam transport line into the accelerating cavity in a radial matching manner, forming, bunching and accelerating the light ion beam by a longitudinal high-frequency electric field generated by the accelerating cavity, focusing the light ion beam by a transverse electric field and a focusing magnetic field generated by the magnetic focusing element, leading the light ion beam to gradually reach the energy required by the injection of the synchrotron, and leading the light ion beam out of the outlet of the linear injector and then conveying the light ion beam into the synchrotron through the medium-energy beam transport line;

d, after light ions are conveyed to the synchrotron, beam current is deflected by the injection cutting magnet and the injection electrostatic deflection plate, the beam current is gradually close to the synchrotron, the included angle between the beam current and a central track is gradually reduced, and an injection preparation state is achieved; in the injection process, the local convex rail magnet gradually descends, injected beam current is smeared from inside to outside in a horizontal phase space, and the beam current gradually fills the whole acceptance;

and e, after the injection is finished, accelerating the light ion beam to reach the energy required by treatment, transmitting the light ion beam to the high-energy beam line through the extraction system, and distributing the light ion beam to the treatment terminal through the high-energy beam line.

Due to the adoption of the technical scheme, the invention has the following advantages:

1. the treatment device of the present invention may be directed to protons and³He、⁴He、⁷various light ions such as Li and the like are accelerated, and not only can the proton be utilized for the whole body treatment, but also the proton can be used³He、⁴He、⁷The light ion beam current such as Li is used for treating superficial (less than or equal to 8cm) tumors to improve the curative effect, such as melanoma, head and neck tumors of five sense organs, prostate tumors, breast tumors and the like, and various ions supplement each other, thereby widening the range of tumor indications of the proton accelerator. Meanwhile, the treatment device has low manufacturing cost and is compatible with a pure proton treatment device in scale, thereby being a general precise external irradiation treatment device.

2. The ion source of the device is different from the traditional proton accelerator, is different from a special carbon beam heavy ion accelerator, and adopts a compact high-charge-state full-permanent-magnet ECR ion sourceThe ion source has the biggest characteristics of simple structure, no injection end vacuum chamber, compact structure, and the diameter of the ion source is only 0.1-0.2 meter, while the diameter of the conventional ECR ion source is 0.4-0.8 meter. And the ion source can generate H with high efficiency₂ ⁺And can generate He in a high charge state²⁺And metallic Li³⁺And the like.

3. Different from conventional H₂ ⁺Or H^-The linear injector in the device is designed based on various light ion beam currents, adopts a high working frequency scheme with an external magnetic focusing structure, and can provide high-quality H₂ ⁺Bundle, and also has high-efficiency acceleration³He、⁴He、⁷The capability of light ion beams such as Li, and the like, and the injector adopts the working frequency of 500-900 MHz, so that the acceleration gradient is higher, the equipment size is more compact, and the occupied area of the device is further reduced.

4. Conventional proton synchrotron mostly injects H₂ ⁺Or H^-Ions are injected in a stripping mode, and the injection accelerator adopts a convex rail-variable multi-circle injection method, so that the high-efficiency injection of various light ion beams can be realized simultaneously. Space charge effects are the main reasons for using the variable-land-rail scheme, e.g. the mass-to-charge ratio of protons is 1, the injection flow is about 200euA strong,⁷Li³⁺the mass-to-charge ratio of the beam current was 7/3, the injection current was about 30euA stronger, and the space charge effect between the same number of injections was 15 times different. To reduce space charge effects of proton beams, increase⁷Li³⁺The invention relates to a device for injecting accumulated particle number by beam current, which adopts a multi-circle injection method of variable convex tracks: for the⁷Li³⁺When the beam with weak space charge effect is adopted, the slowly-descending convex rail is adopted, so that the acceptance of the synchrotron is filled as far as possible by a high-density core of the beam, and the cumulative beam intensity is improved; for beams with strong space charge effects such as protons, the fast-descending convex rail is adopted, so that the beams are distributed in a phase space as uniformly as possible, and the beam loss caused by the nonlinear space charge effect is reduced.

Drawings

FIG. 1 is a schematic diagram of a light ion tumor treatment device according to an embodiment of the present invention;

fig. 2 is a schematic diagram of the overall structure of the micro high-charge-state all-permanent-magnet ECR ion source according to the embodiment of the invention;

FIG. 3 is a schematic diagram of the overall structure of the linear injector with external magnetic focusing structure according to the embodiment of the present invention;

fig. 4 is a schematic diagram of multi-turn injection of beams in the synchrotron according to the embodiment of the present invention;

fig. 5(a) to 5(f) illustrate the phase space evolution during the multi-turn beam injection process according to the embodiment of the present invention;

FIG. 6 shows protons provided in this embodiment of the present invention⁷Li³⁺Injecting a convex rail magnet descending curve;

FIG. 7(a) shows a proton-implanted phase space according to the embodiment of the present invention, and FIG. 7(b) shows a proton-implanted phase space according to the embodiment of the present invention⁷Li³⁺Injecting a phase space;

the respective symbols in the figure are as follows:

1-an air inlet duct; 2-an evaporation furnace; 3-a waveguide; 4-injecting soft iron; 5-injection end magnetic ring; 6-a hexapole magnetic ring; 7-leading-out end magnetic ring; 8-leading out electrodes; 9-an acceleration chamber; 10-a magnetic focusing element; 11-a housing; 12-1 to 12-4 are injection convex rail magnets.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are described clearly and completely below, and it is obvious that the described embodiments are some, not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

The invention provides a general type light ion tumor treatment device, which adopts the combination of a miniature high-charge state full-permanent-magnet ECR ion source, a high-working-frequency linear injector with an external magnetic focusing structure, a variable-convex-track synchrotron and a treatment terminal, improves from the aspects of beam supply type, ion source structure, linear injector structure, injection method and the like, widens the treatment range of cancer types, and reduces the occupied area and the manufacturing cost of the system.

As shown in fig. 1-3, the present invention provides a general type of light ion tumor treatment device, comprising:

the ion source comprises a cylindrical shell 11, wherein an injection end magnetic ring 5 and a leading-out end magnetic ring 7 are respectively arranged at an injection end and a leading-out end of the shell 11, a hexapole magnetic ring 6 is arranged between the injection end magnetic ring 5 and the leading-out end magnetic ring 7, an arc cavity is jointly defined by the injection end magnetic ring 5, the hexapole magnetic ring 6 and the leading-out end magnetic ring 7, an air inlet pipeline 1, an evaporation furnace 2, a waveguide tube 3 and injection soft iron 4 are arranged in the arc cavity close to the injection end of the shell 11, the air inlet pipeline 1 is connected with a gas storage tank and used for conveying gas into the arc cavity, the evaporation furnace 2 is used for evaporating solid molecules or atoms to generate gas, the waveguide tube 3 is used for feeding microwave power into the arc cavity, electrons generate cyclotron resonance under the combined action of a magnetic field and microwaves, the speed is continuously increased, and after the electrons collide with the; an extraction electrode 8 is arranged in an arc cavity close to the extraction end of the shell 11 and is used for extracting light ion beams out of an ion source;

the linear injector is characterized in that the input end of the linear injector is connected with the output end of the ion source through a low-energy beam transport line, the linear injector comprises an acceleration cavity 9 and a magnetic focusing element 10 sleeved outside the acceleration cavity 9, and the magnetic focusing element 10 is used for generating a longitudinal magnetic field and providing extra focusing force for light ion beam current;

the input end of the synchrotron is connected with the output end of the linear injector through an intermediate energy beam transport line, and the beam input end of the synchrotron is provided with an injection cutting magnet, injection convex rail magnets 12-1-12-4 and an injection static deflection plate;

and the treatment terminal is connected with the synchrotron through the high-energy beam transport line and is used for enabling the light ion beam to accurately reach the position of the tumor cell.

Fig. 4 is a schematic diagram of a multi-turn beam injection process, in which the beam is deflected by an injection cutting magnet and an injection electrostatic deflection plate, and is gradually positioned close to a synchrotron, and the included angle between the beam and a central track is gradually reduced, so as to achieve an injection preparation state. At the moment, the convex rail magnets 12-1-12-4 are started, the central track of the synchrotron is locally protruded, and beam current is injected into the acceptance of the synchrotron. In the injection process, the local convex rail magnets 12-1-12-4 gradually descend, injected beams are smeared from inside to outside in the horizontal phase space, and the beams gradually fill the whole acceptance. Fig. 5(a) to 5(f) show the phase space evolution during the multi-turn implantation. The circle in the figure represents the acceptance of the synchrotron, the line in the vertical direction at the right side of the center of the circle represents the injection electrostatic deflection plate, the ellipse at the right side of the injection electrostatic deflection plate represents the injection beam group, the positions of the injection electrostatic deflection plate and the injection beam group are kept unchanged in the injection process, and different colors of the injection beam group represent different turns of injection. In the injection process, the convex rail magnet (namely the circle center) continuously descends, and the injected beam is smeared from the inner side to the outer side of the phase space to gradually fill the whole phase space.

The space charge effect is that the beam ions have charges, so that the ions or the ions and the wall of the vacuum tube have the effect of the charges, and the normal movement of the beam ions is interfered. The main factors influencing the space charge effect comprise energy, mass-to-charge ratio and strong injection flow, and the beam space current with lower energy, lower mass-to-charge ratio and higher injection flow isThe more pronounced the loading effect. The light ion tumor treatment device adopts the linear accelerator as the injector, the energy of different beams is basically consistent, but the difference between the mass-to-charge ratio and the injection flow is larger. For example, the proton mass to charge ratio is 1, the injection flow is about 200euA strong,⁷Li³⁺the mass-to-charge ratio of the beam current was 7/3, the injection current was about 30euA stronger, and the space charge effect between the same number of injections was 15 times different. To reduce space charge effects of proton beams, increase⁷Li³⁺The number of particles is accumulated by injecting the beam, and the light ion tumor treatment device adopts a multi-circle injection method of changing convex tracks. For the⁷Li³⁺When the beam with weak space charge effect is adopted, slowly-descending convex rail magnets 12-1-12-4 are adopted, so that the acceptance of the synchrotron is filled with high-density cores of the beam as much as possible, and the cumulative beam intensity is improved; for beams with strong space charge effects such as protons, fast-descending convex rail magnets 12-1-12-4 are adopted, so that the beams are distributed in a phase space as uniformly as possible, and the beam loss caused by the nonlinear space charge effect is reduced.

FIG. 6 shows protons and⁷Li³⁺and (3) injecting a descending curve of the convex rail magnet, wherein the number of turns in the graph refers to the number of turns of beam injection, the convex rail height is expressed by percentage, and the convex rail magnet 12-1-12-4 is linearly descended firstly and then exponentially descended in the injection process. The proton has strong space charge effect, less injection turns, fast descending speed of the convex rail magnets 12-1 to 12-4,⁷Li³⁺more turns are required to be injected to increase the flow intensity, and the descending speed of the convex track magnets 12-1 to 12-4 is slow.

FIG. 7 shows protons and⁷Li³⁺the horizontal phase space at the completion of the injection. The proton beam injection flow intensity is high, the mass-to-charge ratio is small, the space charge effect is strong, the injection turns are few (8 circles are injected in the figure), the descending speed of the convex rail magnet 12-1-12-4 is high, and a single circle of beam can be distinguished after the injection is finished;⁷Li³⁺the beam injection flow intensity is weak, the mass-to-charge ratio is large, the space charge effect is weak, the injection accumulated flow intensity is increased by increasing the number of injection turns, the convex rail magnets 12-1-12-4 descend slowly, and single-turn beams cannot be distinguished in a phase space after injection is completed.

In this embodiment, it is preferable that the atomic number of the gas or solid molecules or atoms transported by the gas inlet duct 1 is not more than 20.

In the present embodiment, preferably, the gas delivered by the gas inlet pipe 1 includes hydrogen, helium, methane, or a gas containing light ions; solid molecules or atoms include simple substances (e.g., lithium metal) or oxides.

In the present embodiment, the diameter of the housing 11 is preferably 0.1 to 0.2 m.

In this embodiment, the microwave power fed into the waveguide 3 is preferably 10 to 18 GHz.

In this embodiment, the linear injector preferably has an operating frequency of 500 to 900MHz, and the magnetic focusing element 10 is a solenoid. The acceleration chamber 9 in the linear injector provides the longitudinal electric field needed to accelerate the particles while providing a certain focusing effect. The linear injector adopts the working frequency of more than 500-900 MHz, has higher acceleration gradient, reduces the size of an acceleration cavity by about half compared with the conventional linear injector, and is favorable for further reducing the floor area of the device. However, the high operating frequency weakens the transverse electric field focusing ability, and the introduction of the external magnetic focusing element 10 (solenoid) provides the injector with sufficient focusing ability to ensure that it can not only provide high quality H₂ ⁺Bundle, and also has high-efficiency acceleration³He、⁴He、⁷Li, etc. light ion beam.

The invention also provides an operation method of the general type light ion tumor treatment device, which comprises the following steps:

a, when light ions needing gas ionization are treated, gas is conveyed into an arc cavity through a gas inlet pipeline 1, microwave power is fed into the arc cavity through a waveguide tube 3, electrons generate cyclotron resonance under the combined action of a magnetic field and microwaves, the speed is increased continuously, after the electrons collide with gas molecules, outer-layer electrons of the gas molecules are stripped, light ions are generated, the light ions are led out under the action of a leading-out electrode 8 and are conveyed into a linear injector through a low-energy beam transport line;

b, when the solid molecules or atoms are required to be ionized to light ions for treatment, evaporating the solid molecules or atoms through the evaporation furnace 2 to generate steam, sending the steam into the arc cavity, feeding microwave power into the arc cavity by using the waveguide tube 3, generating cyclotron resonance by electrons under the combined action of a magnetic field and microwaves at an increasing speed, stripping electrons on the outer layer of the steam molecules or atoms after colliding with the steam to generate charged light ions, leading the charged light ions out under the action of the leading-out electrode 8, and conveying the charged light ions into the linear injector through a low-energy beam transport line;

c, injecting light ion beams transmitted by a low-energy beam fortune line into an acceleration cavity 9 in a radial matching manner, forming, bunching and accelerating the light ion beams by a longitudinal high-frequency electric field generated by the acceleration cavity 9, focusing the light ion beams by a transverse electric field and a focusing magnetic field generated by a magnetic focusing element, leading the light ion beams to gradually reach the energy required by the injection of the synchrotron, and leading the light ion beams to the synchrotron through the medium-energy beam fortune line after being led out from an outlet of the linear injector;

d, after light ions are conveyed to the synchrotron, deflecting the beams through the injection cutting magnet and the injection static deflection plate, enabling the beams to be gradually close to the synchrotron, gradually reducing the included angle between the beams and the central track to achieve an injection preparation state, starting the injection convex track magnets 12-1-12-4 at the moment, locally protruding the central track of the synchrotron, and enabling the injected beams to enter the acceptance of the synchrotron; in the injection process, the local convex rail magnets 12-1-12-4 gradually descend, injected beams are smeared from inside to outside in a horizontal phase space, and the beams gradually fill the whole acceptance;

and e, after the injection is finished, the light ion beam current is accelerated to reach the energy required by the treatment, and is transmitted to a high-energy beam line through the extraction system, and then the light ion beam current is distributed to a treatment terminal through the high-energy beam line to carry out the cancer treatment.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.