Ionization chamber structure

Abstract

The embodiment of the invention provides an ionization chamber structure. The ionization chamber structure comprises a plurality of electrode plates which are arranged at intervals. The electrode plates comprise polar plates, high-voltage electrodes, collectors and protection electrodes, the high-voltage electrodes and the collectors are arranged on the two opposite sides of the polar plates in the interval direction respectively, and the high-voltage electrodes and the collectors of every two adjacent electrode plates are oppositely arranged; the protection electrode is arranged around the collector in the circumferential direction and is spaced from the collector. The ionization chamber structure is high in measurement efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of particle beam depth dose distribution measurement, and in particular to an ionization chamber structure. Background Art

[0002] The Bragg Peak (BP) effect refers to the phenomenon that when a proton beam enters a tissue, the speed of the protons remains almost constant in the initial path. Due to the extremely fast speed, fewer ionization events occur per unit path, and the energy loss is relatively small. Near the end of the path, due to the continuous occurrence of ionization events, the protons lose energy and slow down, while the slow protons cause more ionization, resulting in an energy deposition peak and then suddenly dropping to zero. Compared with X-rays, electron beams, neutrons and negative π particles commonly used in radiotherapy, proton beams are unanimously evaluated by the high-energy physics and medical communities as a treatment method with better efficacy and fewer side effects due to their special Bragg Peak effect and good radiation biological effects.

[0003] If the Bragg peak can be accurately positioned to cover the tumor area, it is possible to give the tumor a larger dose of radiation while reducing damage to normal tissues and organs and reducing the occurrence of side effects. Therefore, the accurate measurement of the depth dose distribution is directly related to the effect of proton therapy and the personal safety of the patient. In order to give full play to the advantages of precise treatment of radiotherapy (especially proton therapy and heavy ion therapy), protect the patient's normal tissues from irradiation while treating cancer, and minimize the radiation dose, and improve the safety and accuracy of radiotherapy, it is necessary to conduct depth dose distribution measurements every week to ensure the effectiveness of radiotherapy.

[0004] However, when performing particle beam depth dose distribution scanning measurement in related technologies, the measurement efficiency is low. Summary of the invention

[0005] In view of this, the main purpose of the embodiments of the present application is to provide an ionization chamber structure with high measurement efficiency.

[0006] To achieve the above purpose, the technical solution of the embodiment of the present application is implemented as follows:

[0007] The embodiment of the present application provides an ionization chamber structure, including:

[0008] A plurality of electrode plates are arranged at intervals, wherein the electrode plates include an electrode plate, a high-voltage electrode, a collecting electrode and a protective electrode. The high-voltage electrode and the collecting electrode are respectively arranged on opposite sides of the electrode plate along the spacing direction, and the high-voltage electrode and the collecting electrode of two adjacent electrode plates are arranged oppositely; the protective electrode is arranged around the circumference of the collecting electrode and is arranged at intervals from the collecting electrode.

[0009] In one embodiment, the ionization chamber structure includes a shell having a housing cavity, the electrode plate is arranged in the housing cavity, and the shell is electrically connected to the high voltage power supply and the high voltage electrode respectively.

[0010] In one embodiment, the ionization chamber structure includes a high-voltage lead and a wire crimping terminal, the shell includes a lead support plate, the lead support plate has an electrical connection hole, the wire crimping terminal is arranged in the electrical connection hole, one end of the high-voltage lead is connected to the high-voltage pole, and the other end is connected to the wire crimping terminal.

[0011] In one embodiment, the ionization chamber structure includes a signal processor, and the collecting electrode and the protecting electrode are electrically connected to the signal processor respectively.

[0012] In one embodiment, the ionization chamber structure includes an aviation socket and a shell having a accommodating cavity, the electrode plate is arranged in the accommodating cavity, the shell includes an aviation socket support plate, the aviation socket support plate has a mounting hole, the aviation socket is arranged in the mounting hole, and the collecting electrode and the protective electrode are electrically connected to the aviation socket respectively.

[0013] In one embodiment, the ionization chamber structure includes a collecting wire and a protective wire, the collecting electrode is electrically connected to the aviation socket via the collecting wire, the protective electrode is electrically connected to the aviation socket via the protective wire, and an insulating tube is provided at the connection between at least one of the collecting wire and the protective wire and the aviation socket.

[0014] In one embodiment, the ionization chamber structure includes a fastener, and the plurality of electrode plates arranged at intervals include a first electrode plate, a second electrode plate and a third electrode plate, the first electrode plate, the second electrode plate and the third electrode plate are arranged in sequence along the interval direction, the fastener includes a first fastener and a second fastener, the first electrode plate and the second electrode plate are fastened and connected on opposite sides along the first direction by the first fastener respectively; the second electrode plate and the third electrode plate are fastened and connected on opposite sides along the second direction by the second fastener respectively; wherein the first direction, the second direction and the interval direction are perpendicular.

[0015] In one embodiment, the fastener is a PEEK screw.

[0016] In one embodiment, a sensitive area is formed between the high voltage electrode of the electrode plate and the collecting electrode of the adjacent electrode plate, the electrode plate has an air flow channel, the sensitive area is connected to the outside through the air flow channel, and the extension direction of the air flow channel is located within the cross section of the electrode plate; and / or,

[0017] The electrode plate has a first lead channel, the high voltage electrode is electrically connected to the high voltage power supply through the first lead channel, and the extension direction of the first lead channel is located within the cross section of the electrode plate; and / or,

[0018] The ionization chamber structure includes a signal processor, the electrode plate has a second lead channel, the collecting electrode and the protective electrode are electrically connected to the signal processor through the second lead channel respectively, and the extension direction of the second lead channel is located within the cross section of the electrode plate.

[0019] In one embodiment, the material of the electrode plate is polymethyl methacrylate.

[0020] An embodiment of the present application provides an ionization chamber structure, which includes a plurality of electrode plates arranged at intervals. The electrode plates include an electrode plate, a high-voltage electrode, a collecting electrode, and a protective electrode. The electrode plates are respectively provided with a high-voltage electrode and a collecting electrode on opposite sides along the spacing direction, and the high-voltage electrode and the collecting electrode of two adjacent electrode plates are arranged relative to each other; the protective electrode is arranged circumferentially around the collecting electrode, and is arranged at intervals from the collecting electrode. Therefore, on the one hand, by arranging a plurality of electrode plates in the ionization chamber and measuring the dose distribution of particle beams at different depths at the same time, the monoenergetic Bragg peak or the extended Bragg peak can be verified in only one measurement, thereby improving the measurement efficiency, reducing the quality assurance time, and saving radiotherapy resources. On the other hand, arranging the protective electrode on the electrode plate helps to maintain the uniformity of the electric field inside the ionization chamber and prevent electric field distortion, thereby improving the accuracy of the measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of an ionization chamber structure in the first embodiment of the present application;

[0022] Figure 2 for Figure 1 Exploded view of the ionization chamber structure;

[0023] Figure 3 for Figure 1 Schematic diagram of the structure of the medium ionization chamber;

[0024] Figure 4 for Figure 1 Schematic diagram of the assembly of the ionization chamber;

[0025] Figure 5 This is a schematic diagram of the structure of the collector side of the electrode plate in the second embodiment of the present application;

[0026] Figure 6 for Figure 5 Schematic diagram of the structure of the high voltage pole side of the middle electrode plate;

[0027] Figure 7 This is a schematic diagram of an aviation socket in the third embodiment of the present application;

[0028] Figure 8 The Co-60 gamma-ray reference radiation field percentage depth dose curve in the fourth embodiment of the present application;

[0029] Fig. 9 The high-energy photon reference radiation field percentage depth dose distribution verification curve in the fifth embodiment of the present application;

[0030] Fig.10 The percentage depth dose distribution verification curve of the high energy electron reference radiation field in the sixth embodiment of the present application;

[0031] Fig.11 This is a proton beam reference radiation field percentage depth dose distribution verification curve in the seventh embodiment of the present application.

[0032] Description of Reference Numerals

[0033] 10. Electrode plate; 10a. Sensitive area; 11. Electrode plate; 11a. First lead channel; 11b. Second lead channel; 11c. Air flow channel; 12. High voltage electrode; 13. Collecting electrode; 14. Protective electrode; 15. First electrode plate; 16. Second electrode plate; 17. Third electrode plate; 21. Lead support plate; 21a. Electrical connection hole; 22. Aviation socket support plate; 22a. Mounting hole; 23. End plate; 24. Upper shell; 25. Lower shell; 26. Handle; 31. First fastener; 32. Second fastener. DETAILED DESCRIPTION

[0034] In this application, the orientation or position relationship between the "first direction" and the "second direction" is based on the attached Figure 5 The orientation or position relationship shown in the figure is based on the orientation or position relationship of the attached Figure 2 It should be understood that these directional terms are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application.

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. The following embodiments are only used to more clearly illustrate the technical scheme of the present application, and are therefore only used as examples, and the protection scope of the present application cannot be limited by this. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0036] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0037] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "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, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0038] According to the Statistical Bulletin on the Development of my country's Health Care Industry in 2022, released by the Department of Planning, Development and Informatization in 2023, there were 1,716 Class-A tertiary hospitals nationwide at the end of 2021, 65 more than in 2020, and all Class-A tertiary hospitals were equipped with radiotherapy departments. As of January 2024, there are 12 proton / heavy ion therapy centers in operation in my country, and 18 proton / heavy ion therapy centers are under construction or planned in the next three years.

[0039] However, in the relevant technology, domestic radiotherapy centers mainly use finger-type ionization chambers and three-dimensional water tanks to carry out deep dose distribution measurement. It usually takes 3 to 4 hours to complete a complete deep dose distribution measurement, which wastes medical resources to a certain extent.

[0040] An embodiment of the present application provides an ionization chamber structure, see Figure 2 , Figure 3 , Figure 5 and Figure 6 The ionization chamber structure includes a plurality of electrode plates 10 arranged at intervals.

[0041] The electrode plate 10 includes an electrode plate 11, a high voltage electrode 12, a collecting electrode 13 and a protective electrode 14. The high voltage electrode 12 and the collecting electrode 13 are respectively arranged on opposite sides of the electrode plate 11 along the spacing direction, and the high voltage electrode 12 and the collecting electrode 13 of two adjacent electrode plates 10 are arranged oppositely.

[0042] The protection electrode 14 is disposed around the circumference of the collector electrode 13 and is spaced apart from the collector electrode 13 .

[0043] Specifically, the protective electrode 14 refers to an electrode in the ionization chamber, which is electrically connected to a high-voltage power supply to generate a potential difference with the collecting electrode, thereby prompting the charged particles in the particle beam to move toward the collecting electrode 13 and finally be collected by the collecting electrode 13 .

[0044] The collecting electrode 13 refers to an electrode opposite to the high voltage electrode 12 and is used to collect charged particles generated by ionizing radiation.

[0045] The protective electrode 14 is arranged circumferentially around the collector 13, and there is a gap between the protective electrode 14 and the collector 13. That is to say, the protective electrode 14 is an annular electrode extending circumferentially around the collector 13, and the gap area between the protective electrode 14 and the collector 13 is an annular gap area. Since a protective electrode 14 is correspondingly arranged in the circumference of each collector 13, electric field distortion can be prevented, thereby improving the accuracy of measurement. At the same time, since the annular gap area is formed, the insulation effect between the collector 13 and the protective electrode 14 can be improved.

[0046] The spacing distance between the protective electrode 14 and the collecting electrode 13 is not limited. For example, the spacing distance between the protective electrode 14 and the collecting electrode 13 is 2.5 mm.

[0047] The electrode plate 11 serves as a substrate for placing the high voltage electrode 12 , the collecting electrode 13 and the protective electrode 14 , and can absorb the energy of the particle beam, which helps to reduce the size of the ionization chamber structure.

[0048] The number of the plates 11 is not limited, as long as the ionization chamber structure can measure the dose distribution of the particle beam at different depths. For example, the number of the plates 11 is 181.

[0049] The material type of the electrode plate 11 is not limited. For example, the material of the electrode plate 11 is polymethyl methacrylate. Since polymethyl methacrylate (PMMA) is a low atomic number material with scattering properties similar to water, the accuracy of the ionization chamber structure in measuring the depth dose distribution of the particle beam in water can be improved.

[0050] The high voltage electrode 12, the collecting electrode 13 and the protective electrode 14 are formed in any manner. For example, graphite is evaporated or conductive graphite paint is coated on a part of the surface of the electrode plate 11 to form the high voltage electrode 12, the collecting electrode 13 and the protective electrode 14. The high voltage electrode 12 and the collecting electrode 13 are located on opposite sides of the electrode plate 11, and the protective electrode 14 is located on the same side of the electrode plate 11 as the collecting electrode 13.

[0051] The cross-sectional shape and size of the high voltage electrode 12 are not limited, as long as the entire area of ​​the high voltage electrode 12 is located on the electrode plate 11. For example, the cross-sectional shape of the high voltage electrode 12 is a circle with a diameter of 140 mm.

[0052] The cross-sectional shape and size of the collector 13 are not limited, as long as the entire area of ​​the collector 13 is located on the electrode plate 11. For example, the cross-sectional shape of the collector 13 is a circle with a diameter of 120 mm.

[0053] The width of the protection electrode 14 is not limited. For example, the width of the protection electrode 14 is 7.5 mm.

[0054] The embodiment of the present application provides an ionization chamber structure, which includes a plurality of electrode plates 10 arranged at intervals. The electrode plate 10 includes an electrode plate 11, a high voltage electrode 12, a collecting electrode 13 and a protective electrode 14. The electrode plate 11 is provided with a high voltage electrode 12 and a collecting electrode 13 on opposite sides along the spacing direction, and the high voltage electrode 12 and the collecting electrode 13 of two adjacent electrode plates 10 are arranged relative to each other; the protective electrode 14 is arranged around the circumference of the collecting electrode 13, and is arranged at intervals with the collecting electrode 13. Therefore, on the one hand, by arranging a plurality of electrode plates 10 in the ionization chamber and measuring the dose distribution of the particle beam at different depths at the same time, the monoenergetic Bragg peak or the extended Bragg peak can be verified in only one measurement, which improves the measurement efficiency, reduces the quality assurance time and saves radiotherapy resources. On the other hand, the protective electrode 14 is provided on the electrode plate 10, which helps to maintain the uniformity of the electric field inside the ionization chamber, prevents the electric field from being distorted, and thus improves the accuracy of the measurement.

[0055] In one embodiment, please refer to Figure 1 and Figure 2 The ionization chamber structure includes a shell having a receiving cavity, the electrode plate 10 is arranged in the receiving cavity, and the shell is electrically connected to the high voltage power supply and the high voltage electrode 12 respectively. Thus, the interference of electromagnetic noise on the ionization chamber signal can be effectively prevented.

[0056] Specifically, the housing refers to the outer shell of the ionization chamber structure.

[0057] The accommodating cavity refers to the internal space of the shell, which is used to place the electrode plate 10 and other structural components.

[0058] The shell serves as a conductive path, connecting the high-voltage power supply and the high-voltage electrode 12 respectively, so that the high-voltage electrodes 12 of multiple electrode plates 10 do not need to be connected to the high-voltage power supply separately when in use, thereby simplifying the wiring and operation process of the equipment and making the ionization chamber structure more compact.

[0059] The material type of the shell is not limited, as long as the shell has conductivity. For example, the shell is made of aluminum alloy.

[0060] The structural type of the shell is not limited. For example, the shell is composed of two end plates 23, an upper shell 24 and a lower shell 25. The end plates 23, the upper shell 24 and the lower shell 25 are all made of 6061 aluminum alloy and are fixedly connected by flanges. The shell is provided with two handles 26, which are fixed to the opposite ends of the upper shell 24 by flanges. The handles 26 are made of 6061 aluminum alloy.

[0061] In one embodiment, please refer to Figure 2 and Figure 6 The ionization chamber structure includes a high-voltage lead and a wire pressing terminal, the housing includes a lead support plate 21, the lead support plate 21 has an electrical connection hole 21a, the wire pressing terminal is arranged in the electrical connection hole 21a, one end of the high-voltage lead is connected to the high-voltage pole 12, and the other end is connected to the wire pressing terminal. This can improve the stability of the ionization chamber working under high voltage and reduce the measurement error caused by poor contact.

[0062] Specifically, the high-voltage poles 12 of multiple electrode plates 10 are respectively connected to one end of the high-voltage lead, and the other end of the high-voltage lead is pressed into the wire pressing terminal in parallel. The wire pressing terminal is fixed in the electrical connection hole 21a of the lead support plate 21 to electrically connect the high-voltage pole 12 to the shell of the ionization chamber structure.

[0063] The connection method between the high voltage pole 12 and the high voltage lead is not limited.

[0064] For example, the electrode plate 11 has a first lead channel 11a, the high-voltage electrode 12 is electrically connected to the high-voltage power supply through the first lead channel 11a, and the extension direction of the first lead channel 11a is located in the cross section of the electrode plate 11. Thus, the stability of the electrical connection between the high-voltage electrode 12 and the high-voltage power supply is improved.

[0065] Specifically, the extension direction of the first lead channel 11 a is in the same plane as the cross section of the electrode plate 11 .

[0066] The number of the electrical connection holes 21 a is not limited.

[0067] For example, the number of electrical connection holes 21a corresponds to the number of high-voltage poles 12, and a wire crimping terminal is provided in each electrical connection hole 21a. Each high-voltage lead is respectively connected to a high-voltage pole 12 on an electrode plate 10 and a corresponding wire crimping terminal.

[0068] For another example, the number of electrical connection holes 21a is less than the number of electrode plates 10, and each electrical connection hole 21a is provided with a wire pressing terminal, and a single wire pressing terminal is connected to multiple high-voltage leads, thereby reducing the number of holes on the lead support plate 21 and reducing the difficulty of processing.

[0069] In a specific embodiment, a portion of the lead support plate 21 where no electrical connection port is provided is provided with an opening, thereby reducing the weight of the ionization chamber structure.

[0070] In one embodiment, the ionization chamber structure includes a signal processor, and the collector 13 and the protection electrode 14 are electrically connected to the signal processor respectively. Therefore, on the one hand, the protection electrode 14 is electrically connected to the signal processor to reduce leakage current. On the other hand, the signal processor detects the potential of the collector 13 and the protection electrode 14, so that the two are kept at the same potential, thereby preventing electric field distortion.

[0071] In one embodiment, please refer to Figure 2 and Figure 7 The ionization chamber structure includes an aviation socket and a shell with a receiving cavity, the electrode plate 10 is arranged in the receiving cavity, the shell includes an aviation socket support plate 22, the aviation socket support plate 22 has a mounting hole 22a, the aviation socket is arranged in the mounting hole 22a, and the collecting electrode 13 and the protecting electrode 14 are electrically connected to the aviation socket respectively. Therefore, the collecting electrode 13 and the protecting electrode 14 are electrically connected to the signal processor through the aviation socket, which improves the stability of the electrical connection.

[0072] Specifically, the number of mounting holes 22a corresponds to the number of aviation sockets.

[0073] There is no limitation on the connection method between the collecting electrode 13 and the protective electrode 14 and the aviation socket.

[0074] Exemplarily, the ionization chamber structure includes a collection line and a protection line, the collection electrode 13 is electrically connected to the aviation socket through the collection line, the protection electrode 14 is electrically connected to the aviation socket through the protection line, and an insulating tube is sleeved at the connection between at least one of the collection line and the protection line and the aviation socket. Thus, the leakage current of the ionization chamber structure can be reduced.

[0075] Specifically, each pair of two adjacent electrode plates 10 is combined to form a flat ionization chamber, wherein one electrode plate 10 provides a collector 13 for the flat ionization chamber, and the other electrode plate 10 provides a high voltage electrode 12 for the flat ionization chamber. In this way, a plurality of electrode plates 10 arranged at intervals form a plurality of ionization chambers, and the plurality of ionization chambers are defined as the first ionization chamber, the second ionization chamber ... and the Nth ionization chamber in sequence along the interval direction. The aviation socket has 30 pin positions, and the 30 pin positions are defined as the first pin position, the second pin position ... and the 30th pin position in sequence. The first, third, and fourth pin positions of the aviation plug are vacant, and the fifth to 30th pin positions are connected to the collectors 13 of the first to 26th ionization chambers in sequence through the collecting wires. In addition, the protective wires connected to the protective electrodes 14 of the 26 ionization chambers are uniformly welded to the second pin position, thereby realizing the connection between an aviation socket and 26 ionization chambers. According to the connection method mentioned above, all ionization chambers are connected to the aviation socket.

[0076] The connection between at least one of the collecting wire and the protection wire and the aviation socket is provided with an insulating tube, which means that only the connection between the collecting wire and the aviation socket is provided with an insulating tube, or only the connection between the protection wire and the aviation socket is provided with an insulating tube, or both the connection between the collecting wire and the protection wire and the aviation socket are provided with insulating tubes. In this way, the influence of leakage current on the detection result can be further reduced.

[0077] The diameter of the insulating tube is not limited. For example, the diameter of the insulating tube is 1 mm.

[0078] The type of the insulating tube is not limited. For example, the insulating tube is a Teflon PTFE heat shrink tube.

[0079] It can be understood that the electrode plate 11 has a lead channel, the collecting wire passes through the lead channel to connect the collecting electrode 13 and the aviation socket, and the protective wire passes through the lead channel to connect the protective electrode 14 and the aviation socket. The collecting wire and the protective wire can be passed through the same lead channel or through different lead hole channels.

[0080] In a specific embodiment, please refer to Figure 5 The ionization chamber structure includes a signal processor, the electrode plate 11 has a second lead channel 11b, the collector 13 and the protection electrode 14 are electrically connected to the signal processor through the second lead channel 11b, and the extension direction of the second lead channel 11b is located in the cross section of the electrode plate 11. In this way, the stability of the electrical connection between the collector 13 and the protection electrode 14 and the signal processor can be improved.

[0081] Specifically, the collecting wire is passed through the second lead channel 11 b to connect the collecting electrode 13 and the aviation socket, so that the collecting electrode 13 is electrically connected to the signal processor.

[0082] The protection line is passed through the second lead channel 11 b to connect the protection electrode 14 and the aviation socket, so that the protection electrode 14 is electrically connected to the signal processor.

[0083] The extension direction of the second lead channel 11 b is in the same plane as the cross section of the electrode plate 11 .

[0084] In one embodiment, please refer to Figure 4 and Figure 5The ionization chamber structure includes fasteners, a plurality of electrode plates 10 arranged at intervals include a first electrode plate 15, a second electrode plate 16 and a third electrode plate 17, the first electrode plate 15, the second electrode plate 16 and the third electrode plate 17 are arranged in sequence along the interval direction, the fasteners include a first fastener 31 and a second fastener 32, the first electrode plate 15 and the second electrode plate 16 are fastened and connected at opposite sides along the first direction respectively by the first fastener 31; the second electrode plate 16 and the third electrode plate 17 are fastened and connected at opposite sides along the second direction respectively by the second fastener 32; wherein the first direction, the second direction and the interval direction are perpendicular. Thus, the stability of the connection of each electrode plate 10 is improved.

[0085] Specifically, the first fastener 31 fixes both ends of one diagonal line of the first electrode plate 15 and the second electrode plate 16, and the second fastener 32 fixes both ends of another diagonal line of the second electrode plate 16 and the third electrode plate 17. Thus, the fixed connection of the plurality of electrode plates 10 is achieved.

[0086] The fastener may be of any structure, for example, a PEEK screw.

[0087] In one embodiment, please refer to Figure 4 A sensitive region 10a is formed between the high voltage electrode 12 of the electrode plate 10 and the collecting electrode 13 of the adjacent electrode plate 10, and the electrode plate 11 has an airflow channel 11c, through which the sensitive region 10a is connected to the outside world, and the extension direction of the airflow channel 11c is located within the cross section of the electrode plate 11. Therefore, by providing the airflow channel 11c, the sensitive region 10a is connected to the outside world, which helps to maintain the air pressure balance inside the ionization chamber.

[0088] Specifically, the sensitive area 10 a refers to the area between the high-voltage electrode 12 and the collecting electrode 13 that are oppositely arranged on the adjacent electrode plates 10 .

[0089] The number of sensitive regions 10a is determined by the number of electrode plates 10. For example, 181 electrode plates 10 form 180 sensitive regions 10a.

[0090] Particles of the particle beam are ionized in the sensitive region 10 a and float toward the collecting electrode 13 to be collected by the collecting electrode 13 .

[0091] Along the spacing direction, the width of the sensitive area 10a is less than or equal to 2 mm. For example, the width of the sensitive area 10a is 1 mm or 2 mm.

[0092] The air flow channel 11c refers to a channel connecting the sensitive area 10a with the outside.

[0093] The shape, size and number of the air flow channel 11c are not limited, as long as the sensitive area 10a can be connected to the outside.

[0094] The extension direction of the air flow channel 11 c is in the same plane as the cross section of the electrode plate 11 .

[0095] In a specific embodiment, please refer to Figure 8 , Fig. 9 , Fig.10 and Fig.11 The signal processor includes an electrometer, a data acquisition system and a processor. Two adjacent electrode plates 10 are combined to form a flat ionization chamber. The ionization charge of each ionization chamber is transmitted to the electrometer and the data acquisition system through a signal cable. The ion charge will be converted into an absorbed dose display after quantitative measurement. The processor processes the particle percentage dose of each ionization chamber to obtain the reference radiation field percentage depth dose distribution curve of different particle beams. Therefore, the ionization chamber structure can measure the absorbed dose at different depths at one time, which greatly increases the measurement efficiency, reduces the quality assurance time, and saves radiotherapy resources.

[0096] Specifically, the type of particle beam is not limited. For example, the particle beam is Co-60 gamma ray, high energy photon, high energy electron or proton beam.

[0097] In the description of the present application, the description with reference to the terms "in one embodiment", "in some embodiments", "in a specific embodiment", or "exemplary" 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 embodiments of the present application. In the present application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0098] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. An ionization chamber structure, characterized in that: include: A plurality of electrode plates are arranged at intervals, wherein the electrode plates include an electrode plate, a high-voltage electrode, a collecting electrode and a protective electrode. The high-voltage electrode and the collecting electrode are respectively arranged on opposite sides of the electrode plate along the spacing direction, and the high-voltage electrode and the collecting electrode of two adjacent electrode plates are arranged oppositely; the protective electrode is arranged around the circumference of the collecting electrode and is arranged at intervals from the collecting electrode.

2. The ionization chamber structure according to claim 1, characterized in that: The ionization chamber structure comprises a shell having a containing cavity, the electrode plate is arranged in the containing cavity, and the shell is electrically connected to a high voltage power supply and the high voltage electrode respectively.

3. The ionization chamber structure according to claim 2, characterized in that: The ionization chamber structure includes a high-voltage lead and a wire pressing terminal, the shell includes a lead support plate, the lead support plate has an electrical connection hole, the wire pressing terminal is arranged in the electrical connection hole, one end of the high-voltage lead is connected to the high-voltage pole, and the other end is connected to the wire pressing terminal.

4. The ionization chamber structure according to any one of claims 1 to 3, characterized in that: The ionization chamber structure includes a signal processor, and the collecting electrode and the protecting electrode are electrically connected to the signal processor respectively.

5. The ionization chamber structure according to claim 4, characterized in that: The ionization chamber structure includes an aviation socket and a shell with a accommodating cavity, the electrode plate is arranged in the accommodating cavity, the shell includes an aviation socket support plate, the aviation socket support plate has a mounting hole, the aviation socket is arranged in the mounting hole, and the collecting electrode and the protective electrode are electrically connected to the aviation socket respectively.

6. The ionization chamber structure according to claim 5, characterized in that: The ionization chamber structure includes a collecting wire and a protective wire, the collecting electrode is electrically connected to the aviation socket through the collecting wire, the protective electrode is electrically connected to the aviation socket through the protective wire, and an insulating tube is provided at the connection between at least one of the collecting wire and the protective wire and the aviation socket.

7. The ionization chamber structure according to any one of claims 1 to 3, characterized in that: The ionization chamber structure includes fasteners, and the plurality of electrode plates arranged at intervals include a first electrode plate, a second electrode plate and a third electrode plate, the first electrode plate, the second electrode plate and the third electrode plate are arranged in sequence along the interval direction, the fasteners include a first fastener and a second fastener, the first electrode plate and the second electrode plate are fastened and connected at opposite sides along the first direction respectively by the first fasteners; the second electrode plate and the third electrode plate are fastened and connected at opposite sides along the second direction respectively by the second fasteners; wherein the first direction, the second direction and the interval direction are perpendicular.

8. The ionization chamber structure according to claim 7, characterized in that: The fastener is a PEEK screw.

9. The ionization chamber structure according to claim 1, characterized in that: A sensitive area is formed between the high voltage electrode of the electrode plate and the collecting electrode of the adjacent electrode plate, the electrode plate has an air flow channel, the sensitive area is connected to the outside through the air flow channel, and the extension direction of the air flow channel is located within the cross section of the electrode plate; and / or, The electrode plate has a first lead channel, the high voltage electrode is electrically connected to the high voltage power supply through the first lead channel, and the extension direction of the first lead channel is located within the cross section of the electrode plate; and / or, The ionization chamber structure includes a signal processor, the electrode plate has a second lead channel, the collecting electrode and the protective electrode are electrically connected to the signal processor through the second lead channel respectively, and the extension direction of the second lead channel is located within the cross section of the electrode plate.

10. The ionization chamber structure according to any one of claims 1 to 3, characterized in that: The material of the electrode plate is polymethyl methacrylate.

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