Traveling wave electron linear accelerator

Abstract

The application discloses a kind of travelling wave electron linear accelerator, including travelling wave acceleration tube, disc, electron gun, cooling system, titanium window, beam monitoring system, microwave source and feedback control system, and the both ends of travelling wave acceleration tube are provided with electron gun and titanium window, and the inside of travelling wave acceleration tube is equipped with a series of well-designed disc, cooling system is installed on the outer wall of travelling wave acceleration tube, beam monitoring system is set on travelling wave acceleration tube, microwave source is set on the outside of travelling wave acceleration tube, and electron gun, cooling system, beam monitoring system and microwave source are respectively connected with feedback control system.The linear accelerator in the application can output the pulse electron book of 50 kilowatt power peak power, can satisfy the use demand in high-end industrial flaw detection field, and in medical tumor treatment aspect, enough energy can provide more effective treatment dose, for some high degree of malignancy, growth complex tumor, can more accurately kill tumor cell, and treatment effect is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of electron linear accelerator technology, and more particularly to a high-power traveling-wave electron linear accelerator. Background Technology

[0002] In existing technologies, electron linear accelerators are widely used in numerous fields such as industrial flaw detection, medical oncology treatment, scientific research, irradiation sterilization, and radiopharmaceutical preparation. However, most commercially available electron linear accelerators currently have an output beam power limit of 20 kilowatts. For applications with high energy, power, or efficiency requirements, this power level is insufficient, especially in high-end industrial flaw detection, where higher-energy electron beams are needed to penetrate thicker materials to detect internal defects. In specific medical oncology treatments, higher-power electron linear accelerators can provide more effective therapeutic doses and improve treatment outcomes. Therefore, it is necessary to develop a high-power traveling-wave electron linear accelerator. Summary of the Invention

[0003] To address the technical challenges of existing electron linear accelerators having generally low output beam power, which makes it difficult to meet the urgent needs of high-energy, high-power, and high-efficiency applications such as high-end industrial flaw detection of thick materials and precise tumor treatment with efficient dose delivery, a traveling-wave electron linear accelerator with high-power stable output characteristics is proposed. This accelerator aims to break through the traditional power bottleneck and improve energy conversion efficiency.

[0004] The technical solution adopted in this invention is as follows: A traveling-wave electron linear accelerator includes a traveling-wave accelerator tube, disks, a thermionic electron gun, a constant-temperature water-cooling system, a titanium window, a vacuum system, a beam monitoring system, a microwave source, and a feedback control system. The vacuum system is connected to the traveling-wave accelerator tube to maintain a vacuum inside the tube. The thermionic electron gun is located at one end of the traveling-wave accelerator tube, and a titanium window of a certain thickness is located at the other end. A plurality of disks and rings are axially distributed inside the other end of the traveling-wave accelerator tube. The constant-temperature water-cooling system is installed on the outer wall of the traveling-wave accelerator tube. The beam monitoring system is located on the traveling-wave accelerator tube. The microwave source is located outside the traveling-wave accelerator tube and communicates with its interior. The thermionic electron gun, the constant-temperature water-cooling system, the beam monitoring system, and the microwave source are all connected to the feedback control system.

[0005] Preferably, one end of the hot cathode electron gun is inserted into one end of the traveling wave accelerating tube, and the outer wall of the hot cathode electron gun is vacuum-sealed with the traveling wave accelerating tube.

[0006] Preferably, the microwave source is connected to the interior of the traveling wave accelerator tube via a microwave device, and the microwave source is used to input microwaves with a power greater than 50 kilowatts into the interior of the traveling wave accelerator tube.

[0007] As a further preferred embodiment, the device also includes a precision impedance matching device, which is disposed on the outer wall of the traveling wave accelerator tube. The input terminal of the precision impedance matching device is connected to the microwave device, and the output terminal of the precision impedance matching device is connected to the interior of the traveling wave accelerator tube.

[0008] As a further preferred embodiment, the system also includes a focusing and correction system, which is disposed on the outer wall of the traveling wave accelerating tube.

[0009] As a further preferred embodiment, the focusing and correction system includes a focusing electrode, an electromagnetic lens, and an electromagnetic correction lens arranged sequentially along the electron beam delivery direction.

[0010] As a further preferred embodiment, the device also includes a sleeve, a beam intensity monitor, a beam transformer, and an energy spectrum analyzer. One end of the sleeve is fitted onto the outer wall of the other end of the traveling wave accelerator, and the other end of the sleeve is open. The beam intensity monitor and the energy spectrum analyzer are disposed on the inner wall of the sleeve near the titanium window.

[0011] Preferably, the constant temperature water cooling system includes a cooling coil, a constant temperature water cooling unit, and a water pump. The cooling coil is wound around the outer wall of the traveling wave accelerating tube. One end of the coil is connected to the input end of the constant temperature water cooling unit, the input end of the water pump is connected to the output end of the constant temperature water cooling unit, and the output end of the water pump is connected to the other end of the coil.

[0012] The above technical solution has the following advantages or beneficial effects: (1) The linear accelerator in this invention can output a pulsed electron beam with a power of 50 kilowatts, which can meet the needs of high-end industrial flaw detection. Moreover, in the field of medical tumor treatment, sufficient energy can provide more effective treatment dose and treatment depth. For some tumors with high malignancy, complex growth or large depth, it can more accurately kill tumor cells and effectively improve the treatment effect.

[0013] (2) In this invention, by using the low-level control and reference setting of the feedback control system, the beam monitoring system and the microwave source, the beam monitoring system provides real-time feedback of parameters such as the position, intensity and energy distribution of the electron beam. Based on these precise data, the feedback control system adjusts the working state of each component in a timely manner. This can improve the stability of the accelerator operation, ensure the consistency of the electron beam performance, and reduce the risk of equipment failure caused by parameter fluctuations.

[0014] (3) In this invention, by setting up a focusing and correction system, the electron beam can be double focused to ensure the beam size, improve the beam quality and transmission efficiency, greatly increase the energy concentration of the electron beam, reduce energy loss during transmission, and play a more concentrated role when it reaches the target position. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the traveling wave electron linear accelerator in this invention; Figure 2 This is a schematic diagram of the traveling wave electron linear accelerator system in this invention.

[0016] In the figure: 1. Traveling wave accelerator tube; 2. Disk; 3. Titanium window; 4. Microwave source; 5. Thermionic electron gun; 6. Microwave device; 7. Precision impedance matching device; 8. Cooling coil; 9. Microwave output tube; 10. Sleeve; 11. Beam intensity monitor; 12. Energy spectrum analyzer. Detailed Implementation

[0017] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be noted that terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, terms such as "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Please see Figures 1 to 2The diagram illustrates a preferred embodiment of a traveling-wave electron linear accelerator, comprising a traveling-wave accelerator tube 1, disks 2, a hot cathode electron gun 5, a constant-temperature water cooling system, a titanium window 3, a vacuum system, a beam monitoring system, a microwave source 4, and a feedback control system. The vacuum system is connected to the traveling-wave accelerator tube 1 to maintain a vacuum inside the tube. A hot cathode electron gun 5 is disposed at one end of the traveling-wave accelerator tube 1, and a titanium window 3 of a certain thickness is disposed at the other end. Several disks 2 are distributed axially inside the other end of the traveling-wave accelerator tube 1. The constant-temperature water cooling system is installed on the outer wall of the traveling-wave accelerator tube 1. The beam monitoring system is disposed on the traveling-wave accelerator tube 1. The microwave source 4 is disposed on the outside of the traveling-wave accelerator tube 1 and communicates with the inside of the tube. The hot cathode electron gun 5, the constant-temperature water cooling system, the beam monitoring system, and the microwave source 4 are respectively connected to the feedback control system. In this embodiment, the microwave source 4 is used to input electromagnetic waves into the traveling wave accelerating tube 1, while the hot cathode electron gun 5 is used to emit an electron beam. The electron beam gains energy and is accelerated under the action of the microwave electric field of the electromagnetic wave. Then, it passes through multiple disks 2 to change the phase velocity of the electromagnetic wave, so that the phase velocity of the electromagnetic wave matches the speed of the electron beam. This allows the electron beam to continuously gain energy from the electromagnetic wave, thereby accelerating the electron beam.

[0021] A microwave output tube 9 is provided on the side wall of the other end of the traveling wave accelerating tube 1 to export the remaining electromagnetic waves. The microwave output tube 9 is located between the disk 2 and the titanium window 3, and the accelerated electron beam leaves the traveling wave accelerating tube 1 after passing through the titanium window 3.

[0022] In this embodiment, the spacing between two adjacent disks 2 is different, the disk thickness is 5mm, and the aperture of each disk 2 is precisely adjusted, with the smallest aperture being 20mm and the thickness being 3mm. This setting can improve the coupling efficiency of the microwave electric field, so that the energy increase per meter of electrons in the accelerating tube is significantly improved.

[0023] In this embodiment, the spacing between two adjacent disks 2 can be flexibly adjusted according to the beam conditions. By adjusting the distance between the disks 2, the capture efficiency, exit energy, and energy dissipation can be guaranteed.

[0024] Furthermore, as a preferred embodiment, one end of the hot cathode electron gun 5 is inserted into one end of the traveling wave accelerator tube 1, and the outer wall of the hot cathode electron gun 5 is vacuum-sealed with the traveling wave accelerator tube 1. In this embodiment, the microwave source 4 is connected to the interior of the traveling wave accelerator tube 1 through the microwave device 6, and the microwave source 4 is used to input microwaves with a power greater than 50 kilowatts into the interior of the traveling wave accelerator tube 1. Specifically, the peak power can be 5.5 megawatts and the average power can be 75 kilowatts. A precision impedance matching device 7 is provided on the outer wall of the traveling wave accelerator tube 1. The input end of the precision impedance matching device 7 is connected to the microwave device 6, and the output end of the precision impedance matching device 7 is connected to the interior of the traveling wave accelerator tube 1.

[0025] The impedance between the microwave device 6 and the traveling wave accelerating tube 1 can be adjusted in real time by the precision impedance matching device 7, so as to ensure that the microwave energy is efficiently coupled to the accelerating tube, reduce the reflected power, and enable the microwave to be input to the accelerating tube in the best state to provide energy for electron acceleration.

[0026] By iteratively optimizing the structure and electromagnetic field distribution of the traveling wave accelerator tube 1, the impedance and electromagnetic field distribution of the traveling wave accelerator tube can be precisely adjusted, ensuring that the microwave source 4 feeds power precisely into the traveling wave accelerator tube 1 through the microwave device 6. This ensures a precise electromagnetic field distribution inside the traveling wave accelerator tube 1. Especially under error conditions and full-load power conditions, ensuring a precise electromagnetic field distribution is a prerequisite for ensuring capture efficiency, exit energy dissipation, and beam quality.

[0027] Furthermore, as a preferred embodiment, a focusing and correction system is also included, which is disposed on the outer wall of the traveling wave accelerator tube 1. The focusing and correction system includes a series of focusing coils disposed outside the traveling wave accelerator tube 1, which can suppress the space charge effect of the beam and ensure beam quality under high power conditions.

[0028] The focusing and correction system specifically includes a focusing electrode, an electromagnetic lens, an electromagnetic correction lens, and an electromagnetic deflection coil arranged sequentially along the electron beam delivery direction. The hot cathode electron gun 5 can be made of tungsten-barium alloy or lanthanum hexaboride, which increases its emission current density and provides good thermal stability, allowing for continuous and stable electron emission under high power operation. In this embodiment, after the hot cathode electron gun 5 is activated, electrons escape from its emission end and undergo initial acceleration under negative high voltage within the gun. Simultaneously, the electrons are initially focused by the focusing electrode and injected into the traveling wave accelerator 1, where they are further focused by the electromagnetic lens, reducing the beam spot size at the exit.

[0029] The focusing and correction system in this embodiment can precisely control the electromagnetic field, guide the electron beam to converge, and improve the electron beam injection efficiency. Specifically, the focusing electrode voltage is set to 5kV, and the magnetic field strength of the electromagnetic lens is controlled at 0.05T, allowing for adaptive fine-tuning.

[0030] Furthermore, as a preferred embodiment, the system also includes a sleeve 10, a beam intensity monitor 11, a beam transformer, and an energy spectrum analyzer 12. One end of the sleeve 10 is fitted onto the outer wall of the other end of the traveling wave accelerator, and the other end of the sleeve 10 is open. The beam intensity monitor 11 and the energy spectrum analyzer 12 are disposed on the inner wall of the sleeve 10 near the titanium window 3. A beam transformer is also disposed on the inner wall of the sleeve 10 to monitor the beam intensity.

[0031] In this embodiment, the beam intensity monitor 11 is located near the electron beam transmission path, with a measurement accuracy of approximately 0.5%, enabling accurate measurement of the electron beam intensity. The energy spectrum analyzer 12 is positioned near the electron beam transmission path, with an energy resolution of 1%, allowing precise measurement of the electron beam energy distribution. A series of water-cooling systems are installed inside the sleeve 10.

[0032] Furthermore, as a preferred embodiment, the constant-temperature water cooling system includes a cooling coil 8, a constant-temperature water chiller unit, and a water pump. The cooling coil 8 is wound around the outer wall of the traveling wave accelerator tube 1. One end of the coil is connected to the input end of the constant-temperature water chiller unit, the input end of the water pump is connected to the output end of the constant-temperature water chiller unit, and the output end of the water pump is connected to the other end of the coil. In this embodiment, the coolant is pumped into the cooling coil 8 by the water pump, thereby removing heat from the surface of the traveling wave accelerator tube 1 and achieving a cooling effect.

[0033] After heat exchange, the coolant enters the constant-temperature water-cooled unit for further cooling, achieving recycling. In other embodiments, the constant-temperature water-cooling system also includes a cooling flange (cooling water flange) and air-cooling equipment. After entering the cooling flange, the coolant from the constant-temperature water-cooled unit is divided into multiple paths via cooling pipes to achieve zoned cooling of the traveling wave accelerator tube 1. By optimizing the water pressure, coils, and water-cooling layout design of the constant-temperature water-cooling system, the water temperature is precisely adjusted to ensure that the temperature rise of the traveling wave accelerator tube 1 remains within a certain accuracy range.

[0034] In this embodiment, the hot cathode electron gun 5, microwave source 4, precision impedance matching device 7, focusing electrode, electromagnetic lens, electromagnetic correction lens, beam intensity monitor 11, beam transformer, energy spectrum analyzer 12, constant temperature water cooling unit and water pump are respectively connected to the feedback control system, and the feedback control system controls these devices to work.

[0035] In this embodiment, the system also includes modules such as a flow meter, accelerator frequency control, accelerator amplitude control, vacuum monitoring feedback control, cathode control, impedance matching, scanning iron control, and magnet and solenoid control, all connected to the feedback control system.

[0036] In operation, the feedback control system controls the microwave source 4 to input electromagnetic waves into the traveling wave accelerating tube 1, and then controls the thermionic electron gun 5 to emit electrons. The electrons are initially focused by the focusing electrode, and then further focused by the electromagnetic lens 9. The position of the electron beam is then corrected by the electromagnetic correction lens, and it is accelerated under the influence of the electromagnetic field. The disk 2 then changes the phase velocity of the electromagnetic waves, allowing the electron beam to continuously gain energy from the electromagnetic waves, thus accelerating the beam. Finally, the beam exits through the titanium window 3, while the electromagnetic waves are discharged from the microwave output tube 9. During operation, the beam current intensity monitor 11 and the energy spectrum analyzer 12 monitor the state of the electron beam in real time and send the data to the feedback control system. The feedback control system then sends control commands to the microwave source 4, the thermionic electron gun 5, the focusing electrode, the electromagnetic correction lens, and the electromagnetic lens to ensure stable operation of the accelerator.

[0037] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A traveling wave electron linear accelerator, characterized by, The system includes a traveling-wave accelerator tube, disks, a hot cathode electron gun, a constant-temperature water cooling system, a titanium window, a vacuum system, a beam monitoring system, a microwave source, and a feedback control system. The vacuum system is connected to the traveling-wave accelerator tube to maintain a vacuum inside the tube. The hot cathode electron gun is located at one end of the traveling-wave accelerator tube, and a titanium window of a certain thickness is located at the other end. Several disks and rings are distributed axially inside the other end of the traveling-wave accelerator tube. The constant-temperature water cooling system is installed on the outer wall of the traveling-wave accelerator tube. The beam monitoring system is located on the traveling-wave accelerator tube. The microwave source is located outside the traveling-wave accelerator tube and communicates with its interior. The hot cathode electron gun, the constant-temperature water cooling system, the beam monitoring system, and the microwave source are all connected to the feedback control system.

2. The traveling-wave electron linear accelerator as described in claim 1, characterized in that, One end of the hot cathode electron gun is inserted into one end of the traveling wave accelerating tube, and the outer wall of the hot cathode electron gun is vacuum-sealed with the traveling wave accelerating tube.

3. The traveling-wave electron linear accelerator as described in claim 1, characterized in that, The microwave source is connected to the interior of the traveling wave accelerator tube via microwave devices, and the microwave source is used to input microwaves with a power greater than 50 kilowatts into the interior of the traveling wave accelerator tube.

4. The traveling-wave electron linear accelerator as described in claim 3, characterized in that, It also includes a precision impedance matching device, which is disposed on the outer wall of the traveling wave accelerator tube. The input terminal of the precision impedance matching device is connected to the microwave device, and the output terminal of the precision impedance matching device is connected to the interior of the traveling wave accelerator tube.

5. The traveling-wave electron linear accelerator as described in claim 2, characterized in that, It also includes a focusing and correction system, which is provided on the outer wall of the traveling wave accelerating tube.

6. The traveling-wave electron linear accelerator as described in claim 5, characterized in that, The focusing and correction system includes a focusing electrode, an electromagnetic lens, and an electromagnetic correction lens arranged sequentially along the electron beam delivery direction.

7. The traveling-wave electron linear accelerator as described in claim 1, characterized in that, It also includes a sleeve, a beam intensity monitor, a beam transformer, and an energy spectrum analyzer. One end of the sleeve is fitted onto the outer wall of the other end of the traveling wave accelerator, and the other end of the sleeve is open. The beam intensity monitor and the energy spectrum analyzer are disposed on the inner wall of the sleeve near the titanium window.

8. The traveling-wave electron linear accelerator as described in claim 1, characterized in that, The constant temperature water cooling system includes a cooling coil, a constant temperature water cooling unit, and a water pump. The cooling coil is wound around the outer wall of the traveling wave accelerating tube. One end of the coil is connected to the input end of the constant temperature water cooling unit, the input end of the water pump is connected to the output end of the constant temperature water cooling unit, and the output end of the water pump is connected to the other end of the coil.

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