A compact ion implanter and ion implantation method for tumor treatment

Abstract

The present invention relates to a compact ion implanter and an ion implantation method for tumor treatment, wherein the compact ion implanter comprises an ion source, a radio frequency quadrupole field accelerator and an ion transport pipeline, wherein the ion source and the radio frequency quadrupole field accelerator are respectively arranged at two ends of the ion transport pipeline; a pre-buncher is arranged on the ion transport pipeline for longitudinally focusing the ion beam flow along the ion transport pipeline. The compact ion implanter for tumor treatment disclosed by the present invention reduces the volume of the medical accelerator, reduces the manufacturing cost of the accelerator, fully and efficiently gives play to the advantages and characteristics of the proton beam and the heavy ion beam, and makes the proton therapy and carbon ion therapy more convenient and popular.

Description

Technical Field

[0001] The invention relates to the technical field of radiotherapy, and in particular to a compact ion implanter and an ion implantation method for tumor treatment. Background Art

[0002] In recent years, there has been widespread interest both internationally and domestically in spallation neutron sources, accelerator-driven energy sources and other high-power ion beam applications, which are increasingly being used in cancer treatment.

[0003] At present, cancer treatment mainly includes three methods: surgical treatment, chemotherapy and radiotherapy. Among them, radiotherapy includes photon therapy and ion therapy. Compared with photon therapy, ion therapy (including proton and heavy ion therapy) has the advantages of dosimetry advantages on the Bragg peak and high controllability of dose in three-dimensional direction, as well as relatively higher penetration into cell tissues. However, according to statistics, in the past few decades, the number of patients receiving ion therapy has been far lower than that of photon therapy. The reason is that photon therapy devices are small in size and easy to install in the treatment room, while ion therapy devices almost occupy the entire dedicated building. For example, the diameter of the synchrotron used to accelerate proton beams is usually 6-8 meters, and the diameter of the synchrotron used to accelerate carbon ions is 19-25 meters. The huge size and high cost of the accelerator device are important reasons that hinder the widespread popularization of ion therapy. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a compact ion implanter and ion implantation method for tumor treatment, which is used to solve the problem that the large size and high cost of accelerator devices hinder the large-scale popularization of ion therapy.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention discloses a compact ion implanter for tumor treatment, comprising

[0007] An ion source for generating an ion beam;

[0008] A radio frequency quadrupole field accelerator for accelerating ion beams;

[0009] An ion transport pipeline, wherein the ion source and the radio frequency quadrupole field accelerator are respectively arranged at two ends of the ion transport pipeline, and are used to transport the ion beam from the ion source to the radio frequency quadrupole field accelerator;

[0010] The pre-buncher is arranged on the ion transport pipeline and is used for longitudinally focusing the ion beam along the ion transport pipeline.

[0011] Preferably, at least one first solenoid is provided on the ion transport conduit between the ion source and the pre-buncher, for radially focusing the ion beam flow in the ion transport conduit between the ion source and the pre-buncher.

[0012] Preferably, the number of the first solenoid is one, and the first solenoid is arranged in the middle of the ion transport conduit between the ion source and the pre-buncher.

[0013] Preferably, at least one second solenoid is provided on the ion transport conduit between the pre-buncher and the radio frequency quadrupole accelerator for radially focusing the ion beam in the ion transport conduit between the pre-buncher and the radio frequency quadrupole accelerator.

[0014] Preferably, the number of the second solenoids is two, and the two second solenoids are respectively arranged at two ends of the ion transport pipeline between the pre-buncher and the radio frequency quadrupole field accelerator.

[0015] Preferably, the radio frequency quadrupole field accelerator comprises a shell having an octagonal or square shape, and four electrodes are arranged inside the shell to form a four-wing structure.

[0016] Preferably, the radio frequency frequency of the radio frequency quadrupole accelerator is between 470-750 MHz.

[0017] Preferably, the initial phase of the radio frequency quadrupole accelerator is not -90 degrees, but greater than -90 degrees.

[0018] Preferably, the pre-buncher comprises a metal cavity, which is cylindrical, and an ion beam inlet and an ion beam outlet are respectively arranged at two ends of the center line of the metal cavity, and the ion transport pipeline passes through the ion beam inlet of the pre-buncher and passes through the ion beam outlet;

[0019] A tuning port is provided on the side of the metal cavity, and a tuner is installed on the tuning port, and the tuner is used to tune the cavity frequency of the pre-buncher;

[0020] A power coupling port is provided on the side of the metal cavity, and a power coupler is installed on the power coupling port for feeding radio frequency power into the cavity of the pre-buncher, thereby establishing a radio frequency electromagnetic field in the cavity of the pre-buncher;

[0021] A vacuum acquisition port is provided on the side of the metal cavity, and the vacuum acquisition port can be connected to a vacuum pump to extract vacuum from the metal cavity.

[0022] In a second aspect, the present invention discloses an ion implantation method for tumor treatment, using the above-mentioned compact ion implanter for tumor treatment, comprising:

[0023] The ion source generates an ion beam, and the ion beam enters the ion transport pipeline;

[0024] The ion beam flows through a first solenoid, and the first solenoid radially focuses the ion beam in an ion transport conduit between an ion source and a pre-buncher;

[0025] The ion beam flows through a pre-buncher, and the pre-buncher focuses the ion beam in the longitudinal direction along the ion transport channel;

[0026] The ion beam flows through a second solenoid, and the second solenoid radially focuses the ion beam flow in an ion transport conduit between a pre-buncher and a radio frequency quadrupole field accelerator;

[0027] The ion beam passing through the second solenoid finally reaches the radio frequency quadrupole accelerator;

[0028] The ion beam is accelerated by a radio frequency quadrupole accelerator.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (I) The present invention discloses a compact ion implanter and ion implantation method for tumor treatment, wherein the compact ion implanter includes an ion source, a first solenoid, a pre-buncher, a second solenoid and a radio frequency quadrupole field accelerator, and the ion source, the first solenoid, the pre-buncher, the second solenoid and the radio frequency quadrupole field accelerator are sequentially arranged on the ion transport pipeline from left to right, with a compact structure, reducing the volume of the accelerator to reduce the construction scale, and operating at the front end of a miniaturized medical S-band high-gradient linear accelerator device, as a front-end implanter of a high-gradient linear accelerator, for proton and carbon ion tumor treatment. The compact ion implanter for tumor treatment disclosed by the present invention reduces the volume of the medical accelerator, reduces the manufacturing cost of the accelerator, fully and efficiently gives play to the advantages and characteristics of the proton beam and heavy ion beam, making proton therapy and carbon ion therapy more convenient and popular. The ion implantation method will have important value in cancer radiotherapy, and has significant advantages over the existing technology in terms of floor space and construction scale, and is more conducive to promotion and application in hospitals and other places.

[0031] (II) The present invention discloses a compact ion implanter and ion implantation method for tumor treatment. The radio frequency quadrupole accelerator operates in the frequency range of 470-750MHz, and can provide proton and carbon ion beams accelerated to a certain energy for the S-band high-gradient linear accelerator. The compact ion implanter adopts a pre-(external) bunching method to effectively shorten the length of the compact ion implanter and reduce the longitudinal emittance of the beam at the outlet of the radio frequency quadrupole accelerator, thereby achieving a better match between the beam at the outlet of the radio frequency quadrupole accelerator and the S-band high-gradient acceleration structure.

[0032] (III) The present invention discloses a compact ion implanter and an ion implantation method for tumor treatment. The initial phase of the radio frequency quadrupole field accelerator is not the traditional -90 degrees, but is greater than -90 degrees, thereby effectively shortening the length of the compact ion implanter and obtaining a smaller longitudinal emittance, providing a solution for a high-frequency compact ion implanter.

[0033] (IV) Using the compact ion implanter for tumor treatment disclosed in the present invention, a pre-buncher is provided on the ion transport pipeline for longitudinally focusing the ion beam along the ion transport pipeline. Compared with the traditional implanter, the pre-buncher is added to obtain a more compact and better beam transmission and acceleration effect. On the one hand, the length of the compact ion implanter can be shortened, and on the other hand, the longitudinal emittance of the radio frequency quadrupole accelerator outlet beam can be effectively reduced, so that the radio frequency quadrupole accelerator outlet beam can be better matched with the downstream S-band high gradient accelerator. The compact ion implanter for tumor treatment provided by the present invention belongs to a front-end implanter of a linear accelerator, and can manufacture an advanced miniaturized medical accelerator device, which can provide proton and carbon ion beams for tumor radiotherapy and has important social and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic structural diagram of a compact ion implanter for tumor treatment provided in Example 1 of the present invention;

[0035] Figure 2 is a three-dimensional view of the front side of the pre-buncher provided in Example 1 of the present invention;

[0036] Figure 3 It is a three-dimensional view of the side of the pre-buncher provided in Example 1 of the present invention.

[0037] Explanation of the reference numerals: 1-ion source; 2-ion transport pipeline; 3-pre-buncher, 31-ion beam inlet, 32-ion beam outlet, 33-tuning port, 34-power coupling port, 35-vacuum acquisition port; 4-radio frequency quadrupole field accelerator; 51-first solenoid; 52-second solenoid. DETAILED DESCRIPTION

[0038] The exemplary embodiments of the present invention will be described in more detail below with reference to 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.

[0039] In order to realize the miniaturization of medical ion accelerator devices, the present invention proposes a high-frequency compact ion implanter design with small longitudinal emittance, and serves as an implanter for an S-band high-gradient linear accelerator. In the ion implanter scheme provided by the present invention, the initial phase of the radio frequency quadrupole field accelerator is not the traditional -90 degrees, but greater than -90 degrees, thereby effectively shortening the length of the ion implanter, and obtaining a smaller longitudinal emittance, so as to achieve a better matching of the beam with the subsequent (S-band) high-gradient accelerator structure. However, this design will lead to a decrease in the transmission efficiency of the beam in the radio frequency quadrupole field accelerator. In order to overcome this shortcoming, the present invention proposes: before the radio frequency quadrupole field accelerator, a pre-buncher with a frequency consistent with that of the radio frequency quadrupole field accelerator is used to improve the beam transmission efficiency of the radio frequency quadrupole field accelerator. The present invention can be used for a new compact proton / carbon ion tumor treatment device, which has important social and economic benefits.

[0040] The present invention discloses a compact ion implanter for tumor treatment, which is a high-frequency compact implanter for S-band high-gradient linear accelerator. The overall device can generate and accelerate proton or carbon ion beams for tumor treatment. The specific implementation scheme is as follows:

[0041] (1) In order to match the high-gradient acceleration structure, the operating frequency of the radio frequency quadrupole accelerator is selected to be 1 / 4 or 1 / 6 of the operating frequency of the high-gradient structure, usually operating in the range of 470-750 MHz.

[0042] (2) The injection capacity of the first-stage accelerator of the radio frequency quadrupole accelerator depends on the extraction voltage of the ion source, and the extraction energy of the radio frequency quadrupole accelerator depends on the injection energy of the next-stage accelerator.

[0043] (3) In order to shorten the length of the ion implanter and obtain a smaller longitudinal emittance, the initial phase of the radio frequency quadrupole field accelerator is not the traditional -90 degrees, but greater than -90 degrees.

[0044] (4) In order to improve the transmission efficiency of the RF quadrupole accelerator, a pre-buncher with the same frequency as the RF quadrupole accelerator is placed upstream of the RF quadrupole accelerator. The pre-buncher can adopt a Pill-box structure. Matching elements such as solenoid lenses are also placed on the transmission line between the ion source and the RF quadrupole accelerator.

[0045] (5) Due to the high operating frequency of the ion implanter, the radio frequency quadrupole accelerator adopts a four-wing structure.

[0046] Example 1: A compact ion implanter for tumor treatment

[0047] Embodiment 1 of the present invention provides a compact ion implanter for tumor treatment, and the following structural drawings describe its structure in detail.

[0048] refer to Figure 1 The compact ion implanter for tumor treatment comprises an ion source 1, an ion transport pipeline 2, a pre-buncher 3 and a radio frequency quadrupole field accelerator 4.

[0049] The ion source 1 is used to generate an ion beam;

[0050] The radio frequency quadrupole field accelerator 4 is used to accelerate the ion beam;

[0051] The ion source 1 and the radio frequency quadrupole field accelerator 4 are respectively arranged at two ends of the ion transport pipeline 2 . After being emitted from the ion source 1 , the ion beam is transported to the radio frequency quadrupole field accelerator 4 through the ion transport pipeline 2 .

[0052] The ion transport pipeline 2 is provided with a pre-buncher 3 for focusing the ion beam in the longitudinal direction along the ion transport pipeline 2 .

[0053] At least one first solenoid 51 is provided on the ion transport conduit 2 between the ion source 1 and the pre-buncher 3 , and is used to radially focus the ion beam flow in the ion transport conduit 2 between the ion source 1 and the pre-buncher 3 .

[0054] Specifically, the number of the first solenoid 51 is one, and the first solenoid 51 is disposed in the middle of the ion transport pipe 2 between the ion source 1 and the pre-buncher 3 .

[0055] At least one second solenoid 52 is provided on the ion transport conduit 2 between the pre-buncher 3 and the radio frequency quadrupole accelerator 4 for radially focusing the ion beam in the ion transport conduit 2 between the pre-buncher 3 and the radio frequency quadrupole accelerator 4 .

[0056] Specifically, the number of the second solenoids 52 is two, and the two second solenoids 52 are respectively arranged at the two ends of the ion transport pipeline 2 between the pre-buncher 3 and the radio frequency quadrupole accelerator 4 .

[0057] The ion source 1 , the first solenoid 51 , the pre-buncher 3 , the second solenoid 52 and the radio frequency quadrupole accelerator 4 are sequentially arranged on the ion transport pipeline 2 from left to right.

[0058] Radio Frequency Quadrupole (RFQ) accelerator is a low-energy ion linear accelerator widely used as the front-end injector of large ion accelerators. RFQ accelerator can directly accelerate low-energy ions drawn from the ion source, and integrate multiple functions such as longitudinal acceleration, longitudinal clustering, transverse focusing and matching into one structure, so that it can efficiently accelerate high-current ion beams of tens or even hundreds of mA. As a universal pre-accelerator for low-energy and high-current accelerators, RFQ accelerators have been increasingly widely used in large scientific facilities such as spallation neutron sources, accelerator-driven clean nuclear energy systems, neutrino factories, and small accelerator neutron sources. At present, the four-wing RFQ has become a commonly selected acceleration structure in the initial stage of high-current accelerators (from ion sources to energies of several MeV).

[0059] The radio frequency quadrupole accelerator can be roughly divided into four sections from the perspective of beam dynamics. These four acceleration sections are, from front to back, radial matching section (RMS), shaping section (SH), smooth bunching section (GB) and acceleration section (AC). From the perspective of high-frequency structure, it can be divided into four-wing type, four-rod type, cross-finger type, separated coaxial type, etc.

[0060] As a specific implementation, the radio frequency quadrupole field accelerator 4 includes a shell, which is octagonal or square in shape, and four electrodes are arranged in the shell to form a four-wing structure.

[0061] The radio frequency quadrupole accelerator 4 is used as a front-end injector of an S-band high-gradient linear accelerator, and its operating frequency is selected to be 1 / 4 or 1 / 6 of the operating frequency of the high-gradient structure, and the operating range is 470-750 MHz.

[0062] Among them, the radio frequency quadrupole accelerator 4 is used as the first-stage accelerator, and its injection energy depends on the extraction voltage of the ion beam, and the extraction energy of the radio frequency quadrupole accelerator 4 depends on the injection energy of the next-stage accelerator.

[0063] The initial phase of the radio frequency quadrupole field accelerator 4 does not adopt the traditional -90 degrees, but is greater than -90 degrees.

[0064] As a specific implementation, the radio frequency quadrupole accelerator 4 with a four-wing structure inside is a high-frequency radio frequency quadrupole accelerator.

[0065] refer to Figure 2 and Figure 3 The pre-buncher 3 includes a metal cavity, which is cylindrical and has an ion beam inlet 31 and an ion beam outlet 32 ​​. The ion transport pipe 2 passes through the ion beam inlet 31 of the pre-buncher 3 and passes through the ion beam outlet 32 ​​.

[0066] A tuning port 33 is provided on the side of the metal cavity, and a tuner is installed on the tuning port 33, and the tuner is used to tune the cavity frequency of the pre-buncher 3;

[0067] A power coupling port 34 is provided on the side of the metal cavity, and a power coupler is installed on the power coupling port 34 for feeding radio frequency power into the cavity of the pre-buncher 3, thereby establishing a radio frequency electromagnetic field in the cavity of the pre-buncher 3;

[0068] A vacuum acquisition port 35 is provided on the side of the metal cavity, and the vacuum acquisition port 35 can be connected to a vacuum pump to extract vacuum from the metal cavity.

[0069] Specifically, the pre-buncher 3 may adopt a Pill-box structure, wherein the Pill-box is a cylindrical hollow structure radio frequency cavity, and the Pill-box cavity works in TE 010 In this mode, when a radio frequency power of a certain frequency is fed into the cavity, the electromagnetic field established therein will produce a bunching effect on the ion beam. The electromagnetic field frequency of the pre-buncher 3 is consistent with the frequency of the radio frequency quadrupole field accelerator 4.

[0070] Example 2: An ion implantation method for tumor treatment

[0071] Embodiment 2 of the present invention provides an ion implantation method for tumor treatment, using the compact ion implanter for tumor treatment provided in Embodiment 1, and the ion implantation method comprises the following steps:

[0072] The ion source 1 generates an ion beam, and the ion beam enters the ion transport pipeline 2;

[0073] The ion beam flows through the first solenoid 51, and the first solenoid 51 radially focuses the ion beam flow in the ion transport pipe 2 between the ion source 1 and the pre-buncher 3;

[0074] The ion beam flows through the pre-buncher 3, and the pre-buncher 3 focuses the ion beam in the longitudinal direction along the ion transport channel 2;

[0075] The ion beam flows through the second solenoid 52, and the second solenoid 52 radially focuses the ion beam flow in the ion transport pipe 2 between the pre-buncher 3 and the radio frequency quadrupole accelerator 4;

[0076] The ion beam passing through the second solenoid 52 finally reaches the radio frequency quadrupole accelerator 4;

[0077] The radio frequency quadrupole field accelerator 4 accelerates the ion beam.

[0078] Before the ion beam passes through the pre-buncher 3, the vacuum acquisition port 35 is connected to a vacuum pump to evacuate the metal cavity;

[0079] When the ion beam passes through the pre-buncher 3, the tuner of the pre-buncher 3 tunes the cavity frequency of the pre-buncher 3, and the power coupler of the pre-buncher 3 feeds radio frequency power into the cavity of the pre-buncher 3, thereby establishing a radio frequency electromagnetic field in the cavity of the pre-buncher 3.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention 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 make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compact ion implanter for tumor treatment, arranged at the front end of an S-band high-gradient linear accelerator device, as a front-end implanter of the high-gradient linear accelerator, characterized in that: include: An ion source (1) for generating an ion beam; A radio frequency quadrupole field accelerator (4), used for accelerating the ion beam; An ion transport pipeline (2), wherein the ion source (1) and the radio frequency quadrupole field accelerator (4) are respectively arranged at two ends of the ion transport pipeline (2), and are used to transport the ion beam from the ion source (1) to the radio frequency quadrupole field accelerator (4); A pre-buncher (3) is arranged on the ion transport pipe (2) and is used to concentrate the ion beam in the longitudinal direction along the ion transport pipe (2); The radio frequency of the radio frequency quadrupole accelerator (4) is between 470-750 MHz, and provides a proton and carbon ion beam accelerated to a certain energy for the S-band high-gradient linear accelerator; The initial phase of the radio frequency quadrupole accelerator (4) is greater than -90 degrees; The pre-buncher (3) comprises a metal cavity, which is cylindrical, and an ion beam inlet (31) and an ion beam outlet (32) are respectively arranged at two ends of the center line of the metal cavity, and the ion transport pipeline (2) passes through the ion beam inlet (31) of the pre-buncher (3) and passes through the ion beam outlet (32); A tuning port (33) is provided on the side of the metal cavity, and a tuner is installed on the tuning port (33), and the tuner is used to tune the cavity frequency of the pre-buncher (3); A power coupling port (34) is provided on the side of the metal cavity, and a power coupler is installed on the power coupling port (34) for feeding radio frequency power into the cavity of the pre-buncher (3), thereby establishing a radio frequency electromagnetic field in the cavity of the pre-buncher (3); A vacuum acquisition port (35) is provided on the side of the metal cavity, and the vacuum acquisition port (35) can be connected to a vacuum pump to extract vacuum from the metal cavity; The pre-buncher (3) adopts a Pill-box structure, wherein the Pill-box is a cylindrical hollow structure radio frequency cavity. The Pill-box cavity operates in a TE010 mode. When radio frequency power of a certain frequency is fed into the metal cavity, the electromagnetic field established therein will produce a bunching effect on the ion beam. The electromagnetic field frequency of the pre-buncher (3) is consistent with the frequency of the radio frequency quadrupole field accelerator (4).

2. The compact ion implanter for tumor treatment according to claim 1, characterized in that: At least one first solenoid (51) is arranged on the ion transport pipe (2) between the ion source (1) and the pre-buncher (3) and is used to radially focus the ion beam flow in the ion transport pipe (2) between the ion source (1) and the pre-buncher (3).

3. The compact ion implanter for tumor treatment according to claim 2, characterized in that: The number of the first solenoid (51) is one, and the first solenoid (51) is arranged in the middle of the ion transport pipe (2) between the ion source (1) and the pre-buncher (3).

4. The compact ion implanter for tumor treatment according to claim 3, characterized in that: At least one second solenoid (52) is arranged on the ion transport pipeline (2) between the pre-buncher (3) and the radio frequency quadrupole accelerator (4) to radially focus the ion beam flow in the ion transport pipeline (2) between the pre-buncher (3) and the radio frequency quadrupole accelerator (4).

5. The compact ion implanter for tumor treatment according to claim 4, characterized in that: The number of the second solenoids (52) is two, and the two second solenoids (52) are respectively arranged at two ends of the ion transport pipeline (2) between the pre-buncher (3) and the radio frequency quadrupole accelerator (4).

6. The compact ion implanter for tumor treatment according to claim 1, characterized in that: The radio frequency quadrupole field accelerator (4) comprises a shell which is in an octagonal or square shape, and four electrodes are arranged inside the shell to form a four-wing structure.

7. An ion implantation method for tumor treatment, using the compact ion implanter for tumor treatment according to any one of claims 1 to 6, characterized in that: include: The ion source (1) generates an ion beam, and the ion beam enters the ion transport pipeline (2); The ion beam flows through a first solenoid (51), and the first solenoid (51) radially focuses the ion beam flow in an ion transport pipe (2) between an ion source (1) and a pre-buncher (3); The ion beam flows through a pre-buncher (3), and the pre-buncher (3) focuses the ion beam in the longitudinal direction along the ion transport channel (2); The ion beam flows through a second solenoid (52), and the second solenoid (52) radially focuses the ion beam flow in an ion transport pipe (2) between a pre-buncher (3) and a radio frequency quadrupole accelerator (4); The ion beam passing through the second solenoid (52) finally reaches the radio frequency quadrupole accelerator (4); The radio frequency quadrupole field accelerator (4) accelerates the ion beam.

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