Bragg peak detector and use method thereof

Abstract

The invention provides a Bragg peak detector and a use method thereof. The Bragg peak detector comprises a first framework; the first framework comprises a first base, a second base and an annular assembly, the second base is arranged on the first base, the annular assembly comprises a first annular part and a second annular part, and the first annular part and the second annular part are symmetrically arranged on the two end sides of the first base in the first direction; the multi-layer ionization chamber is located between the first annular component and the second annular component in the second direction and arranged on the second base; the first medium assembly is arranged between the first annular component and the multi-layer ionization chamber in the second direction; the second medium assembly is arranged between the multi-layer ionization chamber and the second annular part in the second direction; wherein the multi-layer ionization chamber can respectively set the lengths of the first medium assembly and the second medium assembly along the second direction by moving on the second base along the second direction, so as to respectively adjust the distribution lengths of the liquid medium in the first medium assembly and the second medium assembly along the second direction.

Description

Technical Field

[0001] This invention relates to the field of radiotherapy technology for particle therapy devices, and specifically to a Bragg peak detector and its usage method. Background Technology

[0002] Particle beam therapy is a novel cancer treatment method. Compared to traditional photon or electron therapy equipment, it offers both biological and dose distribution advantages, particularly the Bragg peak (where most of the ion energy is deposited at the end of the beam's range), enabling high precision and safety in clinical irradiation. During clinical particle therapy, the tumor is divided into several slices for irradiation. The irradiation depth is altered by changing the beam energy to target each tumor slice. However, due to the inherent uncertainty of the particle range, deviations in the Bragg peak position from the planned value can alter the actual dose received by both tumor and normal tissues. Therefore, accurately locating the Bragg peak is crucial for precise particle radiotherapy.

[0003] Since the human body is primarily composed of water, the Bragg curve, or dose distribution in human tissues, is clinically determined by analyzing the Bragg curve in water and a series of equivalent parameters between human tissue and water. Traditional Bragg curve testing methods employ a water tank ionization chamber system, using a stepper motor to change the position of the ionization chamber within the tank to obtain the Bragg curve of the incident particles. This method requires several seconds at each test point, and obtaining Bragg curves for all energies takes at least two hours. This poses significant inconvenience for physicists who frequently perform beam quality verification. Furthermore, the system's test results are affected by beam profile uniformity and beam intensity stability. In addition, during routine beam quality verification, the focus is more on the peak position of the Bragg curve for each energy than on the complete Bragg curve for each energy. Therefore, how to quickly and accurately test the peak positions of the Bragg curves for all energies is a pressing issue that needs to be addressed.

[0004] Another method for measuring Bragg curves utilizes a material equivalent to water. By varying its thickness, it simulates water at different depths. Simultaneously, a detector capable of measuring the irradiation dose is placed within this water-equivalent material of varying thicknesses, enabling a single measurement of the Bragg curve. In clinical applications, this detector simulates layered irradiation during actual particle therapy, obtaining Bragg curves for each layer. By superimposing these Bragg curves, the dose-depth distribution across the entire irradiation range can be obtained. However, this technique requires extremely high consistency in the thickness of all equivalent water materials (typically <1 mm) and very high precision in detector assembly; otherwise, it is difficult to guarantee the accuracy of the measured Bragg curves. To ensure testing accuracy and the range of measurable energies, this detector typically requires the design of energy reduction blocks of varying thicknesses. Testing different energy ranges necessitates replacing the corresponding energy reduction blocks, and frequent replacements reduce operational efficiency. Summary of the Invention

[0005] To achieve the above objectives, a first aspect of the present invention provides a Bragg peak detector, comprising: a first architecture; the first architecture including a first base, a second base, and an annular assembly, wherein the second base is disposed on the first base, and the annular assembly includes a first annular component and a second annular component, the first annular component and the second annular component being symmetrically arranged at both ends of the first base along a first direction; a multilayer ionization chamber located between the first annular component and the second annular component along a second direction and disposed on the second base; a first dielectric assembly disposed between the first annular component and the multilayer ionization chamber along the second direction; and a second dielectric assembly disposed between the multilayer ionization chamber and the second annular component along the second direction; wherein the multilayer ionization chamber can be moved along the second direction on the second base to respectively set the lengths of the first dielectric assembly and the second dielectric assembly along the second direction, so as to respectively adjust the distribution length of the liquid medium in the first dielectric assembly and the second dielectric assembly along the second direction.

[0006] In the above scheme, after the incident particle enters the Bragg peak detector, the distribution length of the liquid medium in the first medium component along the second direction corresponds to the plateau region of the Bragg curve of the incident particle, the distribution length of the liquid medium in the second medium component along the second direction corresponds to the post-peak region of the Bragg curve of the incident particle, and the length of the multilayer ionization chamber along the second direction corresponds to the peak region of the Bragg curve of the incident particle.

[0007] In the above scheme, the Bragg peak detector also includes: a motion control component, which is located on the second base and connected to the multi-layer ionization chamber; and a data acquisition component, which is located on the first base and below the second annular component.

[0008] In the above scheme, the multilayer ionization chamber includes multiple water equivalent plates and two water equivalent sealing surfaces. Both the water equivalent plates and the water equivalent sealing surfaces are made of solid water or polymethyl methacrylate water equivalents. The multiple water equivalent plates are arranged side by side along the second direction between the two water equivalent sealing surfaces, and the spacing between each pair of water equivalent plates is 0.1 mm to 2 mm.

[0009] In the above scheme, both sides of the water equivalent plate are coated with aluminum film, the thickness of the water equivalent plate ranges from 0.5mm to 2mm, and the thickness of the aluminum film ranges from 7μm to 25μm.

[0010] In the above scheme, the double-sided aluminum film of the water equivalent plate is led out through two sub-leads, which are respectively located at both ends of the water equivalent plate along a third direction; one side of the double-sided aluminum film serves as a signal electrode to collect beam signals, and the other side serves as a high-voltage electrode to provide a uniform electric field.

[0011] In the above scheme, both the first medium assembly and the second medium assembly include a telescopic hose, multiple support rods, and multiple support rings; the telescopic hose is disposed within the multiple support rings, and the support rings are connected to each other through the support rings; wherein, the telescopic hose contains a liquid medium.

[0012] In the above scheme, one end of the telescopic hose of the first medium assembly is connected to the first annular component along the second direction, and the other end is connected to the multilayer ionization chamber; one end of the telescopic hose of the second medium assembly is connected to the multilayer ionization chamber along the second direction, and the other end is connected to the second annular component; the liquid medium in the first medium assembly and the liquid medium in the second medium assembly are connected through a thin hose, which is arranged inside the shell of the multilayer ionization chamber.

[0013] In the above scheme, the motion control component includes a motor, a slider, and a guide chain. The slider is fixedly connected to the multi-layer ionization chamber. The motor can drive the slider to move the multi-layer ionization chamber on the second base along the second direction. The guide chain can protect the cable between the motor and the slider.

[0014] A second aspect of the present invention provides a method for using a Bragg peak detector, comprising: S1, positioning and preprocessing the detector; S2, adjusting motor parameters according to the energy range of the incident particles; S3, setting a motor control program to drive a slider to move a multi-layer ionization chamber on a second base along a second direction, and obtaining a certain energy test result; S4, based on the test result, repeatedly adjusting the distance the multi-layer ionization chamber moves along the second direction on the second base to complete all energy tests.

[0015] The technical solutions of the embodiments of the present invention have at least the following beneficial effects:

[0016] (1) The Bragg peak detector can quickly measure the Bragg peak position of all particle energies, and can also measure the layered irradiation of simulated actual particles in the treatment process, and obtain the entire Bragg curve of the particle beam in the human body.

[0017] (2) The Bragg peak detector can quickly measure the Bragg peak position of all particle energies. During the measurement, there is no need to enter or leave the treatment room to change the energy reduction block, which improves work efficiency.

[0018] (3) The multilayer ionization chamber of the Bragg peak detector is composed of multiple double-sided aluminum-plated water equivalent plates. By replacing the aluminum-plated polyimide film commonly used in gas detectors with double-sided aluminum-plated water equivalent plates, the size of the Bragg peak detector is greatly reduced, the measurement accuracy is significantly improved, and the assembly work becomes simple and efficient.

[0019] (4) The medium component of the Bragg peak detector completely seals the liquid medium inside the entire detector, which can measure the Bragg peak curve of the beam at any angle and meet the testing requirements of treatment heads at any angle such as 45° treatment head and rotating gantry.

[0020] (5) The Bragg peak detector has an external trigger control mode, which can automatically complete the test of the peak position of the Bragg peak or the entire Bragg curve of all energies based on the beam signal and transducer signal of different particle therapy devices as external trigger signals. Attached Figure Description

[0021] Figure 1 A schematic diagram of the Bragg peak detector according to an embodiment of the present invention is shown.

[0022] Figure 2 A schematic diagram of the main structure of a multilayer ionization chamber according to an embodiment of the present invention is shown.

[0023] Figure 3 The diagram schematically illustrates the Bragg peak curve of a particle according to an embodiment of the present invention;

[0024] Figure 4 The schematic diagram illustrates the working timing of the Bragg peak position fully automatic test mode according to an embodiment of the present invention;

[0025] Figure 5 The diagram illustrates the test results of the nominal energy Bragg peak position of carbon ions according to an embodiment of the present invention.

[0026] Figure 6 The diagram illustrates the accuracy results of the Bragg peak position test for carbon ion point scanning energy according to an embodiment of the present invention.

[0027] Figure 7The diagram schematically illustrates a comparison between the carbon ion point scanning energy and the test results of a standard water tank according to an embodiment of the present invention;

[0028] Figure 8 A flowchart illustrating a method of using a Bragg peak detector according to an embodiment of the present invention is shown. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0030] Figure 1 A schematic diagram of a Bragg peak detector according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of the main structure of a multilayer ionization chamber according to an embodiment of the present invention is shown.

[0031] like Figure 1 As shown, the Bragg peak detector includes: a first architecture 1; the first architecture 1 includes a first base 11, a second base 12, and an annular assembly, wherein the second base 12 is disposed on the first base 11, and the annular assembly includes a first annular component 131 and a second annular component 132, which are symmetrically arranged at both ends of the first base 11 along a first direction X1; a multilayer ionization chamber 2, located between the first annular component 131 and the second annular component 132 along a second direction X2, and disposed on the second base 12; a first dielectric assembly 3, disposed between the first annular component 131 and the multilayer ionization chamber 2 along the second direction X2; and a second dielectric assembly 4, disposed between the multilayer ionization chamber 2 and the second annular component 132 along the second direction X2.

[0032] Furthermore, such as Figure 1 As shown, the Bragg peak detector also includes a motion control component 5, which is mounted on the second base 11 and connected to the multilayer ionization chamber 2. This component is primarily used to drive and control the movement of the multilayer ionization chamber 2 along the second direction X2 on the second base 12. The Bragg peak detector also includes a data acquisition component 6, which is mounted on the first base 11 and located below the second annular component 132.

[0033] Based on the Bragg peak detector described above, the following is a detailed description of the embodiments. First, the first dielectric component and the second dielectric component of the Bragg peak detector will be described in detail.

[0034] Specifically, such as Figure 1 As shown, both the first media assembly 3 and the second media assembly 4 include a telescopic hose 41, multiple support rods 42, and multiple support rings 43. The telescopic hose 41 is disposed within the multiple support rings 43, and the support rings 43 are connected to each other through the support rings 43.

[0035] In an embodiment of the present invention, the telescopic hose 41 contains a liquid medium, which may be water.

[0036] Furthermore, such as Figure 1 As shown, one end of the telescopic hose 41 of the first dielectric assembly 3 along the second direction X2 is connected to the first annular component 131, and the other end is connected to the multilayer ionization chamber 2. One end of the telescopic hose 41 of the second dielectric assembly 4 along the second direction X2 is connected to the multilayer ionization chamber 2, and the other end is connected to the second annular component 132.

[0037] It should be noted that the liquid medium in the first medium assembly 3 and the liquid medium in the second medium assembly 4 are connected by a thin flexible tube, which is located inside the outer shell 23 of the multilayer ionization chamber 2.

[0038] In an embodiment of the present invention, as the multilayer ionization chamber 2 moves along the second direction X2 on the second base 12, the telescopic hose 41 of the first medium assembly 3 and the telescopic hose 41 of the second medium assembly 4 are stretched or compressed along the second direction X2, thereby setting the lengths of the first medium assembly 3 and the second medium assembly 4 along the second direction X2, respectively. This allows for adjustment of the distribution of the liquid medium along the second direction X2 in the first medium assembly 3 and the second medium assembly 4.

[0039] In an embodiment of the present invention, the medium assembly of the Bragg peak detector completely seals the liquid medium inside the entire detector, enabling the measurement of the Bragg peak curve of a beam at any angle, thus meeting the testing requirements of treatment heads at any angle, such as 45° treatment heads and rotating gantry.

[0040] In an embodiment of the present invention, for example, the incident particle enters the detector along the second direction X2 and is detected after passing through the first dielectric component 3, the multilayer ionization chamber 2 and the second dielectric component 4 in sequence.

[0041] Based on the Bragg peak detector described above, the multi-layer ionization chamber of the Bragg peak detector will be described in detail below.

[0042] Specifically, such as Figure 1 and Figure 2 As shown, the multi-layer ionization chamber 2 includes a structural body and a shell 23. The shell 23 is used to protect the multi-layer ionization chamber structural body, and the shell 23 is also connected to the aforementioned motion control component 5. Figure 2As shown, the structure of the multilayer ionization chamber 2 includes multiple water equivalent plates 21 and two water equivalent sealing surfaces 22. The multiple water equivalent plates 21 are arranged side by side along the second direction X2 between the two water equivalent sealing surfaces 22. The two water equivalent sealing surfaces 22 mainly play a sealing role to ensure that the multilayer ionization chamber 2 can be safely isolated from the liquid medium in the first medium assembly 3 and the liquid medium in the second medium assembly 4, respectively, to prevent the liquid medium from entering the multilayer ionization chamber 2.

[0043] For example, the water equivalent plate 21 and the water equivalent sealing surface 22 can both be made of solid water materials or materials such as polymethyl methacrylate (PMMA).

[0044] For example, both sides of the water equivalent plate 21 are coated with aluminum film, the thickness of the water equivalent plate 21 is in the range of 0.5mm to 2mm, and the thickness of the aluminum film is in the range of 7μm to 25μm.

[0045] For example, the number of water equivalent plates 21 can range from 20 to 100. The spacing between each pair of water equivalent plates 21 ranges from 0.1 mm to 2 mm, and the water equivalent plates 21 can be isolated from each other using ceramic rings.

[0046] In embodiments of the present invention, a double-sided aluminized water equivalent plate is used instead of the aluminized polyimide film commonly used in gas detectors. This significantly reduces the size of the detector and solves the problems of large workload and large accuracy errors caused by the current purely manual film stretching and assembly, making the assembly of Bragg peak detectors simple and efficient.

[0047] Furthermore, such as Figure 2 As shown, the double-sided aluminum film of the water equivalent plate 21 is led out through two sub-leads 211, which are respectively disposed at both ends of the water equivalent plate 21 along the third direction X3. One side of the double-sided aluminum film serves as a signal electrode to collect the beam signal, and the other side serves as a high-voltage electrode to provide a uniform electric field.

[0048] It should be noted that, in the embodiments of the present invention, the first direction X1, the second direction X2, and the third direction X3 are all perpendicular to each other.

[0049] It is understandable that each water equivalent plate is equivalent to a single ionization chamber, and each single ionization chamber will output a single channel signal.

[0050] In embodiments of the present invention, by synchronously sampling the output signal of a single ionization chamber, i.e. a single signal pole, the Bragg curve information of the incident particle can be obtained quickly without considering the influence of the incident particle intensity and axial distribution uniformity.

[0051] In an embodiment of the present invention, the multilayer ionization chamber 2 can be moved along the second direction X2 on the second base 12 to respectively set the lengths of the first medium component 3 and the second medium component 4 along the second direction X2, so as to adjust the distribution length of the liquid medium in the first medium component 3 and the second medium component 4 along the second direction X2.

[0052] Figure 3 The diagram illustrates the Bragg peak curve of a particle according to an embodiment of the present invention.

[0053] like Figure 3 As shown, the Bragg curve of the incident particle can be divided into three regions: the plateau region, which is the incident range when the dose deposition of the incident particle changes from the starting point to 50% of the peak value; the peak region, which is the incident range when the dose deposition of the incident particle changes from 50% of the peak value to the peak value and then falls back to 50% of the peak value; and the post-peak region, which is the incident range when the dose deposition of the incident particle changes from 50% of the peak value to close to 0.

[0054] In an embodiment of the present invention, the multilayer ionization chamber 2 can be controlled by the motor 51 of the motion control component 5 to move along the second direction X2 on the second base 12. During rapid, fully automatic Bragg peak position testing, this ensures that the peak region of the Bragg curve of the incident particle falls within the multilayer ionization chamber 2. The peak position of the Bragg peak curve of the incident particle is obtained through corresponding calculation software. The liquid medium in the entire detector automatically adjusts the distribution of the liquid medium in the first medium component 3 and the second medium component 4 along the second direction X2 as the central multilayer ionization chamber moves.

[0055] Specifically, the first dielectric component 3, the multilayer ionization chamber 2, and the second dielectric component 4 of the detector are divided according to the plateau, peak, and post-peak regions of the Bragg curve. The distribution length of the liquid medium along the second direction X2 in the first dielectric component 3 corresponds to the plateau region of the incident particle Bragg curve, i.e., the range corresponding to the change in dose deposition of the incident particles from the initial point to 50% of the peak value. The length of the multilayer ionization chamber 2 along the second direction X2 corresponds to the peak region of the incident particle Bragg curve, i.e., the range corresponding to the change in dose deposition of the incident particles from 50% of the peak value to the peak value and then back to 50% of the peak value. The distribution length of the liquid medium along the second direction X2 in the second dielectric component 4 corresponds to the post-peak region of the incident particle Bragg curve, i.e., the range corresponding to the change in dose deposition of the incident particles from 50% of the peak value to near zero.

[0056] Understandably, as the multilayer ionization chamber 2 moves along the second direction X2 on the second base 12, the telescopic hose 41 of the first medium assembly 3 and the telescopic hose 41 of the second medium assembly 4 are stretched or compressed along the second direction X2, thereby adjusting the lengths of the first medium assembly 3 and the second medium assembly 4 along the second direction X2. This allows for adjustment of the distribution length of the liquid medium along the second direction X2 in the first medium assembly 3 and the second medium assembly 4.

[0057] For example, when using this detector, by moving the multi-layer ionization chamber and thus changing the distribution length of water along the second direction X2 in the first medium component 3, the peak region of the Bragg curve of the incident particle falls on the part of the multi-layer ionization chamber. The position of the peak region of the Bragg curve of the incident particle is determined by the energy of the incident particle and can be obtained by appropriate calculation software.

[0058] Through the embodiments of the present invention, since the Bragg curve is an asymmetric curve that varies with the energy of the incident particle, the detector structure of the embodiments of the present invention corresponds to the shape of the Bragg curve, which can minimize the structural size of the detector while ensuring the measurement accuracy of the Bragg peak region.

[0059] like Figure 1 As shown, in an embodiment of the present invention, the motion control component 5 includes a motor 51, a slider 52, and a guide chain 53. The slider 52 is fixedly connected to the multi-layer ionization chamber 2; the motor 51 drives the slider 52 to move the multi-layer ionization chamber 2 along the second direction X2 on the second base 12; the guide chain 53 protects the cable between the motor 51 and the slider 52.

[0060] Understandably, the motion control assembly 5 is connected to the housing 23 of the multilayer ionization chamber 2, wherein the slider 52 is located on the second base 12 and is completely fixed to the bottom of the multilayer ionization chamber 2. The motor 51 is located on one side of the housing 23 to drive the slider 52 to move the multilayer ionization chamber 2 on the second base 12 along the second direction X2. The guide chain 53 is mainly used to protect the cable between the motor 51 and the slider 52.

[0061] It should be noted that the motion control component 5 is located on the outside of the detector, which effectively avoids immersion in water, improves measurement resolution, and ensures the measurable energy range of the detector.

[0062] Furthermore, the data acquisition component 6 is composed of a multi-channel weak current digitization highly integrated readout component. The weak current signals from multiple channels output by the multi-layer ionization chamber 2 enter a multi-channel current-to-digital conversion ASIC device, which directly converts the weak current signals into digital signals. Then, it interacts with the FPGA through a serial peripheral interface. The data in the FPGA is uploaded to the host computer for display and storage through a gigabit Ethernet interface.

[0063] In an embodiment of the present invention, the data acquisition component 6 has an external trigger mode, which can automatically complete the testing of the Bragg peak position of all energy or the entire Bragg curve based on the beam signal and transducer signal of different particle therapy devices as external trigger signals.

[0064] Figure 4 The schematic diagram illustrates the working timing of the Bragg peak position fully automatic test mode according to an embodiment of the present invention.

[0065] like Figure 4 As shown, taking a carbon ion therapy device as an example, the beam signal is extracted in a pulse manner. The entire extraction cycle is generally less than 6 seconds, and the pulse width is generally less than 1 second. During the fully automatic testing process, the detector of the carbon ion therapy device (i.e., the Bragg peak detector in this embodiment) can adjust the displacement of the multi-layer ionization chamber by reducing the beam pulse extraction according to the beam signal and the transducer signal, so as to ensure that the position of the multi-layer ionization chamber is adjusted before the next beam pulse arrives. At this time, the data acquisition component performs signal integration during the beam pulse, maintains a certain time for signal sampling after the beam pulse ends, and completes signal initialization before the next beam pulse arrives.

[0066] Through embodiments of the present invention, this Bragg peak detector, in fully automated testing mode, can rapidly determine the Bragg peak positions of all particle energies without requiring replacement of the energy reduction block during measurement, thus improving testing efficiency and corresponding treatment efficiency. For example, taking a carbon ion therapy system as an example, determining the Bragg peak positions of 123 energies from 120 MeV to 400 MeV takes only a few minutes. In contrast, existing technologies require approximately two hours for a standard water tank, and even fully equivalent water detectors require more than half an hour of testing time due to the need to replace the energy reduction plate.

[0067] Figure 5 The diagram illustrates the test results of the nominal energy Bragg peak position of carbon ions according to an embodiment of the present invention.

[0068] Based on the aforementioned Bragg peak detector, such as Figure 5As shown, in one embodiment, the detector was used to perform rapid Bragg peak position testing on four nominal energies of the carbon ion therapy system. After calibration of the water tank, the entire test time was 4 minutes, the peak position test accuracy was less than 0.2 mm, the test time was significantly shortened, and the test accuracy far exceeded the error range required by the design.

[0069] Figure 6 The diagram illustrates the accuracy results of the Bragg peak position test for carbon ion point scanning energy according to an embodiment of the present invention. Figure 7 The diagram illustrates a comparison between the carbon ion point scanning energy and the test results of a standard water tank according to an embodiment of the present invention.

[0070] In another embodiment, the detector was used to perform rapid Bragg peak position testing on 123 points of scanning energy of the carbon ion therapy system. After calibration of the water tank, the automatic testing mode was adopted, and the entire testing time was 8 minutes, with a peak position testing accuracy of less than 0.2 mm. Figure 6 and Figure 7 As shown, the test results for all energy levels are basically consistent with the test results for the standard water tank detector. The test time has been significantly shortened, and the test accuracy meets the error range required by the instrument.

[0071] Based on the above embodiments, the present invention provides a method for using a Bragg peak detector.

[0072] Figure 8 A flowchart illustrating a method of using a Bragg peak detector according to an embodiment of the present invention is shown.

[0073] like Figure 8 As shown, the method includes: S1, positioning and preprocessing the detector; S2, adjusting the parameters of motor 51 according to the energy range of the incident particles; S3, setting the control program for motor 51 to drive slider 52 to move the multilayer ionization chamber 2 along the second direction X2 on the second base 12 and obtain a certain energy test result; S4, based on the test result, repeatedly adjusting the distance the multilayer ionization chamber 2 moves along the second direction X2 on the second base 12 to complete all energy tests.

[0074] In one embodiment, please refer to Figure 1 and Figure 8As shown, the specific steps for using this detector to perform fully automated rapid Bragg peak position testing are as follows: First, the detector is positioned, and the testing software and corresponding parameter settings are checked. Then, based on the energy range of the incident particles, the motor parameters of the motion control component are set to adjust the movement of the multilayer ionization chamber, ensuring that the distribution of liquid water in the second direction X2 at the particle incident end (i.e., the first medium component) has a certain length. Further, the Bragg peak position is obtained by fitting the ionization chamber signal, determining whether the multilayer ionization chamber is within the peak region. Finally, the motor parameters are adjusted according to the determination results, and the next energy test is performed until all energy tests are completed.

[0075] In another embodiment, please combine Figure 1 and Figure 8 As shown, the specific steps for performing a complete Bragg peak curve test using this detector are as follows: First, position the detector and start the test software and check the corresponding parameter settings. Then, based on the energy range of the incident particles, adjust the motor parameters of the motion control component to move the multilayer ionization chamber to the foremost position along the second direction X2, closer to the first dielectric component, to ensure that the distribution length of liquid water in the particle incident end (i.e., the first dielectric component) along the second direction X2 is zero. Further, according to the beam period, set the motor control program to gradually move the multilayer ionization chamber until it moves to the rearmost position along the second direction X2, closer to the second dielectric component. Finally, repeat the above steps until all energy tests are completed.

[0076] Those skilled in the art will understand that although the invention has been shown and described with reference to specific exemplary embodiments thereof, they should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Therefore, the scope of the invention should not be limited to the above embodiments, but should be determined not only by the appended claims, but also by their equivalents.

[0077] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A Bragg peak detector, characterized in that, include: First architecture (1); The first structure (1) includes a first base (11), a second base (12) and an annular component, wherein the second base (12) is disposed on the first base (11), and the annular component includes a first annular component (131) and a second annular component (132), wherein the first annular component (131) and the second annular component (132) are symmetrically arranged on both ends of the first base (11) along a first direction; The multilayer ionization chamber (2) is located between the first annular component (131) and the second annular component (132) along the second direction and is disposed on the second base (12); The first dielectric assembly (3) is disposed along the second direction between the first annular component (131) and the multilayer ionization chamber (2); The second dielectric assembly (4) is disposed between the multilayer ionization chamber (2) and the second annular component (132) along the second direction; The multilayer ionization chamber (2) can be moved along the second direction on the second base (12) to set the length of the first medium assembly (3) and the second medium assembly (4) along the second direction, so as to adjust the distribution length of the liquid medium in the first medium assembly (3) and the second medium assembly (4) along the second direction.

2. The Bragg peak detector according to claim 1, characterized in that, After the incident particle enters the Bragg peak detector, the distribution length of the liquid medium in the first medium component (3) along the second direction corresponds to the Bragg curve plateau region of the incident particle, the distribution length of the liquid medium in the second medium component (4) along the second direction corresponds to the Bragg curve post-peak region of the incident particle, and the length of the multilayer ionization chamber (2) along the second direction corresponds to the Bragg curve peak region of the incident particle.

3. The Bragg peak detector according to claim 1, characterized in that, The Bragg peak detector also includes: A motion control component (5) is mounted on the second base (11) and connected to the multilayer ionization chamber (2); The data acquisition component (6) is located on the first base (11) and below the second annular component (132).

4. The Bragg peak detector according to claim 1, characterized in that, The multilayer ionization chamber (2) includes multiple water equivalent plates (21) and two water equivalent sealing surfaces (22), wherein the water equivalent plates (21) and the water equivalent sealing surfaces (22) are both made of solid water or water equivalents of polymethyl methacrylate; The plurality of water equivalent plates (21) are arranged side by side along the second direction between the two water equivalent sealing surfaces (22), and the spacing between each pair of water equivalent plates (21) is 0.1 mm to 2 mm.

5. The Bragg peak detector according to claim 4, characterized in that, The water equivalent plate (21) is coated with aluminum film on both sides. The thickness of the water equivalent plate (21) ranges from 0.5 mm to 2 mm, and the thickness of the aluminum film ranges from 7 μm to 25 μm.

6. The Bragg peak detector according to claim 5, characterized in that, The double-sided aluminum film of the water equivalent plate (21) is led out through two sub-leads (211), and the two sub-leads (211) are respectively located at both ends of the water equivalent plate (21) along a third direction; One side of the double-sided aluminum film serves as a signal electrode for collecting beam signals, while the other side serves as a high-voltage electrode for providing a uniform electric field.

7. The Bragg peak detector according to claim 1, characterized in that, Both the first media assembly (3) and the second media assembly (4) include a telescopic hose (41), multiple support rods (42) and multiple support rings (43); The telescopic hose (41) is disposed within the plurality of support rings (43), and the support rings (43) are connected to each other through the support rings (43); The telescopic hose (41) contains a liquid medium.

8. The Bragg peak detector according to claim 1 or 7, characterized in that, One end of the telescopic hose (41) of the first medium assembly (3) along the second direction is connected to the first annular component (131), and the other end is connected to the multilayer ionization chamber (2). The telescopic hose (41) of the second medium assembly (4) is connected at one end to the multilayer ionization chamber (2) along the second direction, and at the other end to the second annular component (132). The liquid medium in the first medium assembly (3) is connected to the liquid medium in the second medium assembly (4) through a thin hose, which is arranged inside the outer shell (23) of the multilayer ionization chamber (2).

9. The Bragg peak detector according to claim 3, characterized in that, The motion control component (5) includes a motor (51), a slider (52) and a guide chain (53), wherein the slider (52) is fixedly connected to the multilayer ionization chamber (2); The motor (51) can drive the slider (52) to move the multilayer ionization chamber (2) on the second base (12) along the second direction; The guide chain (53) can protect the cable between the motor (51) and the slider (52).

10. A method of using the Bragg peak detector as described in any one of claims 1 to 9, characterized in that, include: S1, Position and preprocess the detector; S2, adjust the parameters of the motor (51) according to the energy range of the incident particles; S3, set the motor (51) control program to drive the slider (52) to move the multilayer ionization chamber (2) on the second base (12) along the second direction and obtain a certain energy test result; S4. Based on the test results, the distance by which the multilayer ionization chamber (2) moves along the second direction on the second base (12) is adjusted multiple times to complete all energy tests.

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