High-gradient particle accelerator and cancer treatment device

Abstract

The invention discloses a high-gradient particle accelerator and a cancer treatment device, and the high-gradient particle accelerator comprises an ion source which is used for generating and leading out a particle beam for treatment; an inlet of the superconducting radio frequency quadrupole field accelerator is connected with the ion source through a low-energy transmission line, and the superconducting radio frequency quadrupole field accelerator is used for pre-accelerating the particle beam generated by the ion source to obtain a low-energy particle beam; an inlet of the superconducting linear acceleration section is connected with an outlet of the superconducting radio frequency quadrupole field accelerator through a first beam transport line, and the superconducting linear acceleration section is used for accelerating the low-energy particle beam led out by the superconducting radio frequency quadrupole field accelerator again to obtain an intermediate-energy particle beam; and an inlet of the annular accelerator is connected with an outlet of the superconducting linear acceleration section through a second beam transport line, and the annular accelerator is used for carrying out ultimate acceleration on the intermediate-energy particle beam led out by the superconducting linear acceleration section so as to obtain a high-energy particle beam with target energy. The scheme that the superconducting linear accelerator is combined with the annular accelerator is adopted, so that particle beam energy is accelerated to target energy meeting cancer treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of medical accelerators, and in particular to a high-gradient particle accelerator and a cancer treatment device. Background Art

[0002] According to data released by the World Health Organization's International Agency for Research on Cancer (IARC), there were approximately 20 million new cancer cases and 10 million deaths worldwide in 2020. Among them, my country had 4.57 million new cancer cases and 3 million deaths, respectively, ranking first in the world. The number of cancer patients and deaths from cancer in my country ranks first in the world. Tumor diseases have seriously threatened people's lives and health, mainly due to the lack of targeted and effective treatments.

[0003] At present, there are three main treatment methods for different tumor conditions in the world: surgery, chemotherapy and radiotherapy. Surgery is one of the earliest and most commonly used cancer treatment methods. It aims to cure or control cancer by removing the tumor and the surrounding affected tissues. Its advantage is that it can directly remove the tumor and quickly relieve symptoms. However, surgical treatment has a long recovery period, may produce multiple complications, and cannot completely remove cancer cells that have spread, so there is a possibility of recurrence. Chemotherapy can treat cancer that has spread throughout the body, and its effect is usually better than surgery, but its side effects are significant and may cause damage to normal cells. Radiotherapy uses rays to kill cancer cells or shrink tumors. It has the advantages of high precision and fewer side effects, and has shown significant advantages in cancer treatment. Particle therapy based on high-energy particle beams is one of the most advanced radiotherapy technologies for treating cancer.

[0004] The main devices currently used for cancer treatment include proton therapy and heavy ion therapy. The main technical route for proton therapy is a cyclotron or linear injector combined with a synchrotron; the technical route for heavy ion therapy includes cyclotron injection combined with a circular accelerator or a linear injector combined with a synchrotron. However, accelerator devices based on charged particles have two common problems: one is that the high-frequency power consumption is large. Normally, the power obtained by the particles is only one-quarter of the total power, and the remaining three-quarters are high-frequency power consumption, resulting in a large amount of power waste; the second is that energy regulation is difficult. Tumor treatment has certain specificity and selectivity. There are limitations in the treatment of tumors of different types and depths, which invisibly increases the cost of cancer treatment devices and limits the effectiveness of their market promotion. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a high-gradient particle accelerator and a cancer treatment device, which aims to accelerate the particle beam energy to a target energy that meets cancer treatment by using a superconducting linear accelerator combined with a circular accelerator.

[0006] To achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a high-gradient particle accelerator, comprising: an ion source for generating and extracting a therapeutic particle beam; a superconducting radio frequency quadrupole field accelerator, wherein the inlet of the superconducting radio frequency quadrupole field accelerator is connected to the ion source through a low-energy transmission line, and is used to pre-accelerate the particle beam generated by the ion source to obtain a low-energy particle beam; a superconducting linear acceleration section, wherein the inlet of the superconducting linear acceleration section is connected to the outlet of the superconducting radio frequency quadrupole field accelerator through a first beam transmission line, and is used to re-accelerate the low-energy particle beam extracted from the superconducting radio frequency quadrupole field accelerator to obtain a medium-energy particle beam; and a circular accelerator, wherein the inlet of the circular accelerator is connected to the outlet of the superconducting linear acceleration section through a second beam transmission line, and is used to ultimately accelerate the medium-energy particle beam extracted from the superconducting linear acceleration section to obtain a high-energy particle beam of target energy.

[0007] Preferably, the low-energy transmission line comprises several solenoids, a secondary magnet and a chopper; the solenoid is used to generate a magnetic field to control and focus the beam so as to keep the beam on the low-energy transmission line; the secondary magnet is used to analyze the impurity particle beam, and the secondary magnet optimizes the edge angle to achieve symmetrical transmission of the beam; the chopper is a beam transverse chopper with a rising edge not exceeding 20ns.

[0008] Preferably, the frequency of the superconducting radio frequency quadrupole accelerator is selected to be 125-200 MHz, the cavity voltage is selected to be 50-70 kV, the sparking coefficient is selected to be between 1 and 1.6, and the outlet energy is designed to be 1.5-3 MeV / u.

[0009] Preferably, the first beam transport line is composed of several quadrupole lenses and bunchers, and the quadrupole lenses and bunchers are used to match the low-energy particle beam led out by the superconducting radio frequency quadrupole field accelerator to the downstream superconducting linear acceleration section, so as to achieve high-efficiency transmission of the beam.

[0010] Preferably, the superconducting linear acceleration section comprises a cryostat, an interdigital superconducting cavity, a coupler and a tuner, wherein the interdigital superconducting cavity is arranged inside the cryostat, and the cryostat is used to provide a low-temperature, non-magnetic, vacuum environment for the interdigital superconducting cavity; the interdigital superconducting cavity comprises n-stage drift tubes arranged at intervals, the inlet of the first-stage drift tube is connected to the first beam transport line, and the outlet of the n-stage drift tube is connected to the second beam transport line; the coupler is connected to the coupling port of the interdigital superconducting cavity, and is used to feed radio frequency power to the interdigital superconducting cavity; the tuner is connected to the helium tank of the interdigital superconducting cavity through a flexible hinge, and the tuner is used to apply a mechanical force to the interdigital superconducting cavity through a scissor-fork conversion mechanism to achieve frequency adjustment of the interdigital superconducting cavity.

[0011] As a preference, the interdigital superconducting cavity adopts a multi-cell variable period structure, that is, the length and acceleration gap of the drift tube at each stage are variable. i The length of the drift tube 91 is ,in For the i The beam velocity at the exit of the drift tube is is the high frequency cycle time of the cavity, i =1,2,… n .

[0012] Preferably, the material of the interdigital superconducting cavity is Nb3Sn, MgB2 or NbN.

[0013] Preferably, the second beam transport line is mainly composed of a deflection magnet and several quadrupole lenses, wherein the deflection magnet is used to deflect the medium-energy particle beam to the downstream circular accelerator, and the quadrupole lens satisfies the beam matching from the linear accelerator to the circular accelerator, thereby realizing efficient transmission of the beam.

[0014] Preferably, the annular accelerator is a cyclotron, a synchrotron or a FFAG alternating gradient accelerator.

[0015] In a second aspect, the present invention provides a cancer treatment device, comprising the high gradient particle accelerator as described in the first aspect of the present invention and at least one treatment terminal, wherein the at least one treatment terminal is connected to the outlet of the circular accelerator.

[0016] The present invention adopts the above technical solution, which has the following advantages: 1. The present invention proposes a high-gradient particle accelerator based on a combination of a superconducting linear injector and a circular accelerator. The accelerator adopts a CH superconducting cavity with a multi-cell variable period structure, making full use of its high energy storage advantage. In the short pulse working mode, the CH superconducting cavity can work stably within a range of 1 to 2 times the design voltage parameter, so that the energy of the injected beam within 1 meter can reach 4MeV / u to 7MeV / u, thereby greatly improving the acceleration efficiency, greatly shortening the overall length of the linear injector, reducing the accelerator footprint, and reducing the construction cost of the accelerator.

[0017] 2. The injector acceleration structure of the present invention uses a superconducting RFQ accelerator and a multi-cell variable period structure CH superconducting cavity to achieve high-efficiency acceleration of particles. The high-frequency power loss is only tens of watts, and a power source of hundreds of watts can meet the operation of the injector. Compared with the room temperature RFQ accelerator, the high-frequency power consumption is reduced by two orders of magnitude, which not only significantly reduces the construction cost of the accelerator, but also greatly reduces its operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings: Figure 1 A schematic diagram of the structure of a high-gradient particle accelerator provided in Example 1 of the present invention; Figure 2 A schematic diagram of the structure of a superconducting linear acceleration section provided in Example 1 of the present invention; The marks in the figure are as follows: 1- ion source; 2- low energy transmission line; 3- superconducting RFQ accelerator; 4- first beam transport line; 5- superconducting linear acceleration section; 6- second beam transport line; 7- circular accelerator; 8- cryostat; 9- CH superconducting cavity; 10- coupler; 11- tuner; 91- drift tube. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0020] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0024] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0025] In an accelerator-based cancer treatment device, the main function of the accelerator is to provide ions with a certain energy and current intensity to the treatment terminal. Existing cancer treatment devices mostly use a combination of a room temperature linear accelerator and a cyclotron or synchrotron. A room temperature linear injector can accelerate the beam from a lower energy, but its high-frequency power consumption is large, accounting for almost 3 / 4 of the accelerator's operating power, generally in the order of a few kilowatts or even tens of kilowatts, and the operating cost is high. In order to solve this problem, the present invention provides a high-gradient particle accelerator and a cancer treatment device.

[0026] The high gradient particle accelerator and cancer treatment device provided by the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0027] Embodiment 1: See also Figure 1 , this embodiment provides a high gradient particle accelerator, comprising: An ion source 1, used for generating and extracting a particle beam (such as a proton beam or a heavy ion beam) for treatment. In particular, the beam intensity of the particle beam is not less than 10 mA and the energy is 30-50 keV; A superconducting RFQ (Radio Frequency Quadrupole Accelerator) accelerator 3, the entrance of which is connected to the ion source 1 via a low-energy transmission line 2, and is used for pre-accelerating the particle beam generated by the ion source 1 to obtain a low-energy particle beam; A superconducting linear acceleration section 5, the entrance of which is connected to the exit of the superconducting RFQ accelerator 3 through a first beam transport line 4, and is used to re-accelerate the low-energy particle beam drawn out of the superconducting RFQ accelerator 3 to obtain a medium-energy particle beam; The entrance of the circular accelerator 7 is connected to the exit of the superconducting linear acceleration section 5 through the second beam transport line 6, and is used to ultimately accelerate the medium-energy particle beam led out of the superconducting linear acceleration section 5 to obtain a high-energy particle beam with target energy.

[0028] In the above embodiment, preferably, the low-energy transmission line 2 includes several solenoids, a secondary magnet and a chopper. The solenoid is also called a spiral coil, which is used to generate a magnetic field. When it generates a magnetic field, the beam can be controlled and focused so that the beam remains on the low-energy transmission line 2. The secondary magnet is used for the analysis of the impurity particle beam, and the secondary magnet optimizes the edge angle to achieve symmetrical transmission of the beam. The chopper is a beam transverse chopper with a rising edge of no more than 20ns, which can cut off the "tail" ions before and after the beam to reduce the beam loss of the downstream accelerator.

[0029] In the above embodiment, preferably, the frequency of the superconducting RFQ accelerator 3 is selected to be 125-200 MHz, the cavity voltage is selected to be 50-70 kV, the sparking coefficient is selected to be between 1 and 1.6, and the outlet energy is designed to be 1.5-3 MeV / u.

[0030] In the above embodiment, preferably, the first beam transport line 4 is mainly composed of several quadrupole lenses and bunchers. The function of the quadrupole lenses and bunchers is to meet the matching of the low-energy particle beam led out by the superconducting RFQ accelerator 3 to the downstream superconducting linear acceleration section 5, so as to achieve high-efficiency transmission of the beam.

[0031] In the above embodiments, preferably, please refer to Figure 2 The superconducting linear acceleration section 5 includes a cryostat 8, a cross-digital (CH) superconducting cavity 9, a coupler 10 and a tuner 11. The CH superconducting cavity 9 is arranged inside the cryostat 8. The cryostat 8 is used to provide a low-temperature, non-magnetic, vacuum environment for the CH superconducting cavity 9. The CH superconducting cavity 9 includes n-stage drift tubes 91 arranged in intervals inside the cryostat 8. The inlet of the first-stage drift tube 91 is connected to the first beam transport line 4, and the outlet of the n-stage drift tube 91 is connected to the second beam transport line 6; the coupler 10 is connected to the coupling port of the CH superconducting cavity 9, and is used to feed radio frequency power to the CH superconducting cavity 9; the tuner 11 is connected to the helium tank of the CH superconducting cavity 9 through a flexible hinge, and the tuner 11 is used to apply a mechanical force to the CH superconducting cavity 9 through a scissor-fork conversion mechanism to achieve frequency adjustment of the CH superconducting cavity 9.

[0032] In the above embodiment, preferably, please continue to refer to Figure 2 , CH superconducting cavity 9 adopts a multi-cell variable period structure, The length of drift tube 91 and the acceleration gap are variable. i The length of the drift tube 91 is ,in For the i The beam velocity at the exit of the drift tube 91 is is the high frequency cycle time of the cavity, i =1,2,… n. Multi-cell variable period structure It changes with the beam speed, which can achieve a large acceptance of the CH superconducting cavity 9. At the same time, in the short pulse mode, the CH superconducting cavity 9 can operate at 1 to 2 times the cavity design voltage parameters, and achieve high-efficiency acceleration of the proton beam or heavy ion beam to 4MeV / u~7MeV / u within 1 meter.

[0033] In the above embodiments, preferably, the CH superconducting cavity 9 is made of low-temperature superconducting materials (such as Nb3Sn, MgB2 or NbN, etc.).

[0034] In the above embodiment, preferably, the CH superconducting cavity 9 adopts conduction cooling technology to maintain the cavity operating in a superconducting state, that is, it is proposed to transfer the generated heat to the cooling medium through the thermal conductivity of the material, and the cooling medium takes away the heat to maintain the overall low-temperature working state of the system.

[0035] In the above embodiment, preferably, the second beam transport line 6 is mainly composed of a deflection magnet and several quadrupole lenses, wherein the deflection magnet is used to deflect the medium-energy particle beam to the downstream circular accelerator 7, and the quadrupole lens satisfies the beam matching from the linear accelerator to the circular accelerator 7, thereby realizing efficient transmission of the beam.

[0036] In the above embodiment, preferably, the annular accelerator 7 may be a cyclotron accelerator, a synchrotron accelerator or a FFAG alternating gradient accelerator.

[0037] Embodiment 2: Based on the high gradient particle accelerator provided in Example 1, the present invention further provides a cancer treatment device, comprising the high gradient particle accelerator as in Example 1 and at least one treatment terminal, wherein the at least one treatment terminal is connected to the outlet of the circular accelerator 7 .

[0038] It should be noted that the implementation method of the above-mentioned high-gradient particle accelerator embodiment is also applicable to the embodiment of the cancer treatment device and can achieve the same technical effect, which will not be repeated here.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A high gradient particle accelerator, characterized in that: include: Ion source, used to generate and extract therapeutic particle beam; A superconducting radio frequency quadrupole field accelerator, the inlet of which is connected to the ion source via a low-energy transmission line, and is used to pre-accelerate the particle beam generated by the ion source to obtain a low-energy particle beam; A superconducting linear acceleration section, the entrance of which is connected to the exit of the superconducting radio frequency quadrupole accelerator through a first beam transport line, and is used to re-accelerate the low-energy particle beam drawn out by the superconducting radio frequency quadrupole accelerator to obtain a medium-energy particle beam; A ring accelerator, the entrance of which is connected to the exit of the superconducting linear acceleration section through a second beam transport line, and is used to ultimately accelerate the medium-energy particle beam led out of the superconducting linear acceleration section to obtain a high-energy particle beam of target energy.

2. The high gradient particle accelerator according to claim 1, characterized in that: The low-energy transmission line includes several solenoids, a secondary magnet and a chopper; the solenoid is used to generate a magnetic field to control and focus the beam so that the beam remains on the low-energy transmission line; the secondary magnet is used to analyze the impurity particle beam, and the secondary magnet optimizes the edge angle to achieve symmetrical transmission of the beam; the chopper is a beam transverse chopper with a rising edge of no more than 20ns.

3. The high gradient particle accelerator according to claim 1, characterized in that: The frequency of the superconducting radio frequency quadrupole accelerator is selected to be 125-200 MHz, the cavity voltage is selected to be 50-70 kV, the sparking coefficient is selected to be between 1 and 1.6, and the outlet energy is designed to be 1.5-3 MeV / u.

4. The high gradient particle accelerator according to claim 1, characterized in that: The first beam transport line is composed of several quadrupole lenses and bunchers, which are used to match the low-energy particle beam led out by the superconducting radio frequency quadrupole field accelerator to the downstream superconducting linear acceleration section, thereby realizing high-efficiency transmission of the beam.

5. The high gradient particle accelerator according to claim 1, characterized in that: The superconducting linear acceleration section includes a cryostat, an interdigital superconducting cavity, a coupler and a tuner. The interdigital superconducting cavity is arranged inside the cryostat. The cryostat is used to provide a low-temperature, non-magnetic and vacuum environment for the interdigital superconducting cavity. The interdigital superconducting cavity includes n-stage drift tubes arranged at intervals. The inlet of the first-stage drift tube is connected to the first beam transport line, and the outlet of the n-stage drift tube is connected to the second beam transport line. The coupler is connected to the coupling port of the interdigital superconducting cavity and is used to feed radio frequency power to the interdigital superconducting cavity. The tuner is connected to the helium tank of the interdigital superconducting cavity through a flexible hinge. The tuner is used to apply a mechanical force to the interdigital superconducting cavity through a scissor conversion mechanism to achieve frequency adjustment of the interdigital superconducting cavity.

6. The high gradient particle accelerator according to claim 5, characterized in that: The cross-finger superconducting cavity adopts a multi-cell variable period structure, that is, the length and acceleration gap of the drift tube at each stage are variable. i The length of the drift tube 91 is ,in For the i The beam velocity at the exit of the drift tube is is the high frequency cycle time of the cavity, i =1,2,… n .

7. The high gradient particle accelerator according to claim 5, characterized in that: The material of the cross-digital superconducting cavity is Nb3Sn, MgB2 or NbN.

8. The high gradient particle accelerator according to claim 1, characterized in that: The second beam transport line is mainly composed of a deflection magnet and several quadrupole lenses, wherein the deflection magnet is used to deflect the medium-energy particle beam to the downstream circular accelerator, and the quadrupole lens satisfies the beam matching from the linear accelerator to the circular accelerator, thereby realizing high-efficiency transmission of the beam.

9. The high gradient particle accelerator according to claim 1, characterized in that: The circular accelerator is a cyclotron, a synchrotron or a FFAG alternating gradient accelerator.

10. A cancer treatment device, characterized in that: It comprises the high gradient particle accelerator as claimed in any one of claims 1 to 9 and at least one treatment terminal, wherein the at least one treatment terminal is connected to the outlet of the circular accelerator.

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