HK1119907A1 - Multi-energy frequency doubling particle accelerator and method thereof - Google Patents

Description

Multi-energy frequency-doubling particle accelerator and method thereof

Technical Field

The invention relates to an accelerator technology, in particular to a multifunctional frequency doubling particle accelerator with a simple structure and improved working speed and a method thereof.

Background

The electron accelerator is widely applied to the fields of industrial nondestructive testing, customs container testing, radiology, electron beam irradiation and the like. For example, high-energy CT devices for inspecting defect-free objects such as boilers, engines, robotic arm frames, missiles, etc. have been used to inspect baggage, packages, and containers in airports, customs, public areas, to identify contraband items including guns, knives, explosives, drugs, weapons of mass destruction, and various contraband items that do not comply with the customs clearance. A typical radiation inspection system consists of a radiation source, a detector, and an imaging device. The object to be detected passes between a radiation source and a detector, radiation generated by the radiation source, such as X-rays, Y-rays and neutrons, is transmitted through the object and then detected and measured by the detector, and the intensity of the radiation is weakened in the process of penetrating the object, and the weakening degree is related to the material and the density of the object. The intensity of the radiation measured by the detector is therefore a function of the material and the density of the measured object. And the imaging equipment processes and analyzes the measurement result of the detector to finally obtain an image reflecting the shape, size and density of the article.

In addition, the electron accelerator is also widely applied to the fields of radiation medicine and radiation technology, such as tumor treatment, radiation disinfection, radiation sterilization, radiation quarantine, radiation degradation, radiation crosslinking, radiation modification and the like. The main technical index of the accelerator in the irradiation field is the irradiation processing capability, namely the energy of an electron beam and the beam power. The energy of the electron beam determines the depth of the irradiation treatment, and the higher the energy of the electron beam, the greater the depth of the irradiation treatment, i.e. the higher the energy of the electron beam, the greater the volume (depth) of the object can be irradiated. The beam power determines the irradiation processing speed, that is, the larger the beam power is, the more the number of the objects can be irradiated.

The dual-energy or multi-energy electron accelerator system refers to an electron accelerator system capable of outputting electron beams with two or more energies. Compared with the traditional single-energy electron accelerator system, the dual-energy or multi-energy electron accelerator system not only diversifies single-machine energy, but also has the greater technical advantage that the dual-energy or multi-energy electron accelerator system can be combined with a new-generation detector system, a data image processing system and the like to distinguish different material materials. The shape of a substance can only be identified by applying the single-energy accelerator system in the fields of traditional industrial nondestructive testing, customs container testing, high-energy CT and the like, and the shape and the material of the substance can be identified by applying the dual-energy or multi-energy accelerator system, so that explosives, drugs, weapons, other harmful substances and smuggled articles carried in a large container transported across the border can be effectively checked. Therefore, the dual-energy or multi-energy accelerator system has wider application prospect.

To achieve the object of substance identification, patent document 1(WO 9314419) proposes to adopt a configuration in which: the two accelerators with different energies work in parallel, respectively carry out radiation scanning imaging on the same object, and carry out difference comparison on the two image information so as to obtain the material information of the object. Further, patent document 2(WO 2005111590) also proposes a scheme of bombarding the same target with two accelerators from different directions to realize dual-energy radiation. However, because this configuration requires two accelerators and two separate detector systems, the number of equipment is large, the cost is high, and the floor space is large.

Further, patent document 3(US 2004202272) proposes a multi-energy particle beam accelerator which generates a particle beam having a first energy when operated in a first mode and a particle beam having a second energy when operated in a second mode, and which changes the shape of a cavity, that is, changes the resonance frequency and the electromagnetic field distribution within the cavity, by repeatedly inserting or extracting an object into or from the cavity of a bunching section, thereby outputting particle beams having two energies.

However, the scheme proposed in patent document 3 uses a mechanical device to switch the first particle beam to the second particle beam, and cannot meet the requirement of a switching speed of millisecond order in some applications. Therefore, it is necessary to develop a multi-energy electron accelerator which can not only eliminate the problem of the complicated structure of the dual accelerator configuration but also satisfy the requirement of the operation performance.

Disclosure of Invention

The present invention has been accomplished in view of the above problems. The invention aims to provide a multifunctional frequency doubling particle accelerator which is simple in structure and improves the working speed and a method thereof.

In one aspect of the present invention, a multi-energy frequency-doubled particle accelerator is provided, comprising: the pulse power generation unit is used for generating N pulse signals with different powers, wherein N is greater than or equal to 2; n microwave power generating units, under the control of control signals, respectively generating N microwaves with different energies based on the N pulse signals; a power mixing unit having N inlets and one outlet, for inputting corresponding microwaves of the N microwaves from each inlet of the N inlets, and outputting the N microwaves from the one outlet, respectively; a particle beam generating unit for generating N particle beams in synchronization with the N microwaves; and an accelerating unit that accelerates the N particle beams by the N microwaves, respectively.

According to an embodiment of the present invention, the accelerator further comprises a single synchronization unit disposed between the power mixing unit and the acceleration unit for synchronizing a characteristic frequency of the acceleration unit and an operating frequency of each of the N microwave power generation units.

According to an embodiment of the present invention, the accelerator further includes N synchronizing units respectively disposed between the respective microwave power generating units and the power mixing unit, for respectively synchronizing a characteristic frequency of the accelerating unit and an operating frequency of each of the N microwave power generating units.

According to one embodiment of the invention, the synchronization unit comprises: an incident wave sampling waveguide that samples each of the N microwaves output from the one outlet of the power mixing unit to obtain an incident wave; a circulator which sends each of the N microwaves into the acceleration unit and outputs a corresponding microwave reflected from the acceleration unit; a reflected wave sampling waveguide for sampling the reflected corresponding microwave to obtain a reflected wave; the automatic phase-locking frequency stabilizing device compares and analyzes the incident wave and the reflected wave and generates a synchronizing signal for respectively synchronizing the characteristic frequency of the accelerating unit and the working frequency of each of the N microwave power generating units; and an absorption load absorbing a reflected wave output from the circulator.

According to an embodiment of the present invention, the automatic phase-locking frequency stabilization apparatus includes: a variable attenuator for adjusting the amplitudes of the incident wave and the reflected wave and outputting an incident signal and a reflected signal; the phase discriminator is used for adjusting the phases of the incident signal and the reflected signal and outputting a first voltage and a second voltage; a preamplifier for amplifying a difference between the first voltage and the second voltage to output an adjustment signal; the servo amplifier is used for amplifying the adjusting signal and outputting a driving signal; and the channel selector outputs the driving signal to the corresponding microwave power generation unit under the control of the control signal.

According to one embodiment of the invention, the pulsed power generation unit comprises a single pulsed power source which supplies energy to the N microwave power generation units in a time-shared manner under control of a control signal.

According to an embodiment of the present invention, the pulse power generation unit includes N pulse power sources that respectively supply energy to the N microwave power generation units at different times under the control of the control signal.

According to one embodiment of the present invention, the particle beam generating unit includes an electron gun generating an electron beam and a gun power supply supplying power to the electron gun.

According to an embodiment of the invention, the power mixing unit comprises N-1 mixing rings each having two inlets and one outlet, wherein the difference in central arc lengths of the two microwave paths between one inlet and the other inlet is an integer multiple of the guided wave wavelength plus half the guided wave wavelength, the difference in central arc lengths of the two microwave paths between the one inlet and the other outlet is an integer multiple of the guided wave wavelength, and the difference in central arc lengths of the two microwave paths between the other inlet and the other outlet is an integer multiple of the guided wave wavelength.

In another aspect of the present invention, a multi-energy frequency-doubled particle accelerator is provided, comprising: the pulse power generation unit is used for generating N pulse signals with the same power, wherein N is greater than or equal to 2; n microwave power generating units, under the control of the control signal, respectively generating N microwaves with the same energy based on the N pulse signals; a power mixing unit having N inlets and one outlet, for inputting corresponding microwaves of the N microwaves from each inlet of the N inlets, and outputting the N microwaves from the one outlet, respectively; a particle beam generating unit for generating N particle beams in synchronization with the N microwaves; and an accelerating unit that accelerates the N particle beams by the N microwaves, respectively.

In another aspect of the invention, a method of accelerating a particle beam is presented, comprising the steps of: generating N pulse signals with different powers, wherein N is greater than or equal to 2; under the control of a control signal, respectively generating N microwaves with different energies based on the N pulse signals; mixing the N microwaves by using a power mixing unit having N inlets to which corresponding microwaves of the N microwaves are input from respective inlets of the N inlets and one outlet from which the N microwaves are output; generating N particle beams in synchronization with the N microwaves; and accelerating the N particle beams by using the N microwaves respectively.

In a further aspect of the invention, a method of accelerating a particle beam is presented, comprising the steps of: generating N pulse signals with the same power, wherein N is greater than or equal to 2; under the control of a control signal, respectively generating N microwaves with the same energy based on the N pulse signals; mixing the N microwaves by using a power mixing unit having N inlets to which corresponding microwaves of the N microwaves are input from respective inlets of the N inlets and one outlet from which the N microwaves are output; generating N particle beams in synchronization with the N microwaves; and accelerating the N particle beams by using the N microwaves respectively.

The multi-energy frequency doubling particle accelerator is used for identifying substances in the field of radiation scanning imaging, and can acquire images of object objects under different radiation energies in one scanning process by using only one accelerator, one set of detector system and one imaging system, so that the object imaging and the substance identification can be quickly realized, and explosives, drugs, weapons, other harmful substances and smuggled goods carried in a large container transported across the border can be effectively checked. Meanwhile, the accelerator has high working frequency, high scanning and imaging speed and greatly improved processing efficiency. Compared with the prior art adopting a double accelerator technology, the device has the advantages of greatly reduced equipment number, small occupied area, low cost, high scanning imaging speed and high efficiency.

The multi-energy frequency doubling particle accelerator can also be applied to other irradiation fields, such as irradiation treatment, irradiation disinfection, irradiation sterilization, irradiation quarantine, irradiation degradation, irradiation crosslinking, irradiation modification and the like. Different irradiation energies can be selected according to different irradiation objects, so that a better irradiation treatment effect is obtained, and meanwhile, due to the fact that a plurality of microwave power sources are adopted, the working frequency is multiplied, the power of an accelerator is large, and the irradiation treatment capacity is enhanced.

Drawings

Embodiments of the invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate corresponding, similar or analogous elements, and in which:

fig. 1 shows a schematic structural diagram of a double-energy frequency-doubled electron linear accelerator according to a first embodiment of the invention;

FIG. 2 is a timing diagram illustrating the operation of portions of the double energy frequency doubled electron linac shown in FIG. 1;

FIG. 3 shows a cross-sectional view of the mixing ring shown in FIG. 1;

FIG. 4 shows a block diagram of an AFC device as shown in FIG. 1;

FIG. 5 shows a variation of the dual energy frequency doubled electron linac according to the first embodiment of the present invention, in which the circulator is mounted between the magnetron and the mixing ring;

fig. 6 shows a schematic structural diagram of a multi-energy frequency-doubled electron linear accelerator according to a second embodiment of the invention;

FIG. 7 is a timing diagram illustrating the operation of the components of the multiple energy frequency doubling electron linac shown in FIG. 6;

fig. 8 is a timing diagram illustrating components of the multiple energy frequency doubling electronic linear accelerator shown in fig. 6 when the multiple energy frequency doubling electronic linear accelerator is operated in a single energy frequency doubling state.

Detailed Description

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the invention. It will be understood, however, to one skilled in the art, that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention.

Fig. 1 shows a schematic structural diagram of a double-energy frequency-doubled electron linear accelerator according to a first embodiment of the invention. As shown in fig. 1, the double-energy frequency-doubled electron linac according to the first embodiment is mainly composed of a pulse power source 1, microwave power sources 2a and 2b such as magnetrons, a power mixer 3, an incident wave sampling waveguide 4, a circulator 5, a reflected wave sampling waveguide 6, an absorption load 7, an AFC device 8, an acceleration tube 9, an electron gun 10, an electron gun power supply 11, a control device 12 such as a trigger circuit, and the like. Further, the incident wave sampling waveguide 4, the circulator 5, the reflected wave sampling waveguide 6, the absorption load 7, and the AFC device 8 constitute a synchronization device 13 for synchronizing the characteristic frequency of the acceleration tube 9 and the operating frequencies of the microwave power sources 2a and 2 b.

Fig. 2 shows the timing of the operation of the major components of the double energy frequency doubled electron linac shown in fig. 1 and the relative intensities of the generated voltages, currents, microwave powers or electron beam energies. Reference symbol a represents a trigger pulse sequence generated by the control device 12, reference symbol B represents a group of pulse voltages output by the pulse power source 1, reference symbol C represents another group of pulse voltages output by the pulse power source 1, the amplitude of the pulse voltages is smaller than that of the pulse voltages B, and reference symbol D represents microwave power generated by the magnetron 1 under the action of the pulse voltages B; reference symbol E represents the microwave power generated by the magnetron 2 under the action of the pulse voltage C, the amplitude of which is smaller than the microwave power D; reference symbol F denotes an output of the microwave powers D and E after mixing in the power mixer 3; reference symbol G denotes high voltage of the electron gun with different amplitudes generated by the electron gun power supply 11; reference character H denotes the magnitude of two energies of the accelerated electrons in the acceleration tube 9.

As shown in fig. 1 and 2, the control device 12 triggers and controls the action of the pulse power source 1 at a certain time sequence a, and the pulse power source 1 excites the magnetron 2a to work at a larger power at a first moment, so that the magnetron 2a generates an output with a larger microwave power, and the microwave output enters the accelerating tube 9 through the mixer 3, the incident wave sampling waveguide 4 and the circulator 5.

The control device 12 activates the pulse power source 1 and also the electron gun power source 11, the electron gun power source 11 generating a gun high voltage of a smaller amplitude at a first time. The electron gun 10 feeds a smaller number of electrons into the acceleration tube 9 under the effect of this gun high pressure, and these smaller electrons are accelerated in the acceleration tube 9 by the above-mentioned larger microwave power, and obtain a higher energy.

The pulse power source 1 excites the magnetron 2b to work with a smaller power at a second moment, so that the magnetron 2b generates an output with a smaller microwave power, and the output microwave enters the accelerating tube 9 through the mixer 3, the incident wave sampling waveguide 4 and the circulator 5.

The control device 12 triggers the pulse power source 1 and also the electron gun power source 11, the electron gun power source 11 generates a gun high voltage with a larger amplitude at the second moment, the electron gun 10 sends a larger amount of electrons into the accelerating tube 9 under the action of the gun high voltage, and the larger amount of electrons are accelerated by smaller microwave power in the accelerating tube 9 to obtain lower energy.

The accelerator repeats the same operations every two subsequent times with the operating states at the first time and the second time as one cycle, and an electron beam with alternating high and low energies is obtained. The unconsumed microwave power reflected by the accelerating tube 9 enters the absorption load 7 through the circulator 5 and the reflected wave sampling waveguide 6 and is completely absorbed by the absorption load 7. The AFC device 8 acquires information of the incident wave and the reflected wave from the incident wave sampling waveguide 4 and the reflected wave sampling waveguide 6, respectively, compares and analyzes the information, and adjusts the operating frequencies of the magnetron 2a and the magnetron 2b under the control of the control device 12, respectively, so that the operating frequencies are matched with the resonant frequency of the acceleration tube 9, thereby ensuring the effective acceleration effect of the electron beam.

Thus, in an accelerator system, two microwave power sources are used to obtain two electron beams with different energies, and the accelerated operating frequency is 2 times that of a single microwave power source.

In the double energy frequency doubling electron linac system according to the first embodiment described above, the magnetron is used as a microwave power source to generate microwaves, but a klystron may also be used. The accelerating tube 9 may be a standing wave accelerating tube or a traveling wave accelerating tube.

Further, the pulse power source 1 such as a pulse modulator may be one, or may be two corresponding to the two magnetrons 2a and 2b, respectively. The circulator 5 plays a role of power isolation, that is, microwaves generated by the magnetrons 2a and 2b can enter the accelerating tube 9, and the microwave power reflected from the accelerating tube 9 can only enter the absorption load 7 due to the unidirectional isolation function of the circulator 5, which can effectively prevent the reflected microwaves from influencing the magnetrons 2a and 2 b. The circulator 5 may be a three-terminal circulator or a four-terminal circulator. As shown in fig. 1, in the case of the three-terminal circulator 5, the microwave power coming from the port a is output from the port b, and the microwave power coming from the port b can be output only from the port c, but not returned to the port a.

Fig. 3 is a schematic cross-sectional view of a mixing ring. The mixing ring 3 is a power combiner which primarily functions to allow microwave power incident at different times from each inlet to be output from the same outlet. The main structure of the mixing ring 3 is a circular ring with a rectangular cross section, and two inlets, namely an inlet a, an inlet b and an outlet c, which are distributed according to a certain wavelength relationship are arranged on the side surface. Thus, there are two paths between any two ports through which microwaves can pass. If L is used_ab，L_bc，L_caThe lengths of the central arcs of the circular ring segments between the inlet a and the inlet b, the inlet b and the outlet c, and the outlet c and the inlet a are respectively expressed, and then the following relations are satisfied:

for example,

in the above equation set (1), n is an integer, λ_gFor the guided wave length of the microwave used in the accelerator in the waveguide, the first equation in equation set (1) indicates that the difference between the central arc lengths of the two microwave paths between the inlet a and the outlet c is the full wavelength, the second equation indicates that the difference between the central arc lengths of the two microwave paths between the inlet a and the inlet b is the full wavelength plus one half wavelength, and the third equation indicates that the difference between the central arc lengths of the two microwave paths between the inlet b and the outlet c is the full wavelength.

Thus, microwave power entering from one inlet is divided into two paths for transmission, and at the outlet, the two paths of microwaves are added positively to obtain microwave power which is identical to that of the inlet and then exits from the outlet.

FIG. 4 is a schematic diagram of the structure of an AFC device as shown in FIG. 1. The AFC device 8 includes a variable attenuator 13, a phase detector 14, a preamplifier 15, a servo amplifier 16, and a channel selector 17. After the incident wave IW and the reflected wave RW are amplitude-adjusted by the variable attenuator 13, the output incident signal IS and the reflected signal RS enter the phase discriminator 15 for phase adjustment and synthesis, and then two voltage signals VS1 and VS2 are output. The two voltage signals VS1 and VS2 are compared in the preamplifier 15 and the difference between them is amplified to output the adjustment signal AS 1. Likewise, the AFC device 8 generates a further adjustment signal AS2 for a further incident wave and a further reflected wave. The adjustment signal AS1 or AS2 further amplifies the output drive signal DS1 or DS2 via the servo amplifier 16.

The channel selector 17 sends the driving signal DS1 or DS2 to the different magnetrons 2a or 2b at different times under the action of the control signal CS sent by the control device 12, and adjusts the frequency of the driving signal DS1 or DS2, so that the operating frequencies of the magnetrons 2a and 2b are always consistent with the characteristic frequency of the accelerating tube 9, thereby ensuring the stability of the system operation. The number of the output channels of the channel selector 17 may be more than two, and the specific number is the same as the number of the microwave power sources in the multi-energy frequency doubling electronic linear accelerator system.

The structure and operation of the multiple energy frequency doubling electron linear accelerator of the invention are described above by taking the case that the circulator 5 is installed between the power combiner and the accelerating tube. However, the circulator 5 may be installed between each microwave power source and the mixing ring.

Fig. 5 shows a variation of the dual energy frequency doubled electron linac according to the first embodiment of the present invention, in which the circulator 5 is installed between the magnetron and the mixing ring. In this installation mode, the number of incident wave sampling waveguides 4a and 4b, circulators 5a and 5b, reflected wave sampling waveguides 6a and 6b, absorbing loads 7a and 7b, AFC devices 8a and 8b is the same as the number of magnetrons as microwave power sources. In this configuration, although the number of devices is increased relative to the configuration shown in fig. 1, the system is more complex, but the critical devices such as circulators 5a and 5b and absorbing loads 7a and 7b carry less power in the system, only the power generated by a single microwave power source, and therefore they are technically easier to implement, and the low power circulators and absorbing loads are also less costly.

Similarly, the incident wave sampling waveguide 4a, the circulator 5a, the reflected wave sampling waveguide 6a, the absorption load 7a, and the AFC device 8a constitute a synchronizing device 13a for synchronizing the characteristic frequency of the accelerating tube 9 and the operating frequency of the microwave power source 2 a. The incident wave sampling waveguide 4b, the circulator 5b, the reflected wave sampling waveguide 6b, the absorption load 7b, and the AFC device 8b constitute a synchronization device 13b for synchronizing the characteristic frequency of the acceleration tube 9 and the operating frequency of the microwave power source 2 b.

In this configuration, the operation timing and principle of the system are substantially the same as those of fig. 1, except that: the unconsumed microwave power reflected by the accelerating tube 9 enters through the port c of the mixing ring 3, is divided into two parts from the port a and the port b, respectively reaches the two circulators 5a and 5b, enters the absorption loads 7a and 7b through the respective reflected wave sampling waveguides 6a and 6b, and is completely absorbed by the absorption loads 7a and 7 b.

In addition, the AFC devices 8a and 8b still acquire information of the incident wave and the reflected wave from the incident wave sampling waveguides 4a and 4b and the reflected wave sampling waveguides 6a and 6b, perform comparative analysis thereon, and operate under the control of the control device 12, but only need one output to perform frequency adjustment on the corresponding magnetron 2a or 2 b.

The structure and operation of the double-energy frequency-doubled electron linear accelerator according to the first embodiment of the present invention are described above, but the present invention may also adopt a configuration in which the number of pulse power sources is greater than 2.

Fig. 6 shows a schematic structural diagram of a multiple-energy frequency-doubling electron linear accelerator according to a second embodiment of the present invention, which is obtained by expanding the double-energy frequency-doubling electron linear accelerator system of the first embodiment.

In the electron linear accelerator according to the second embodiment of the present invention, the pulse power source, the microwave power source, and the power combiner can be cascaded and increased according to the target requirement, and the working principle is similar to that of a double-energy frequency-doubling electron linear accelerator. For example, n pulsed power sources 1a, 1b, … …, 1c, n magnetrons 2a, 2b, … …, 2c, n-1 mixing loops 3a, 3b, … …, 3c are shown in fig. 6. The control device has outputs T1, T2, … … and Tn connected to the n pulse power sources, respectively, and n magnetrons output M1, M2 and … …, respectively. Mn and the AFC device 8 has n outputs for controlling the n magnetrons respectively.

Alternatively, the above-described pulse power source may be configured to output pulse power to the n magnetrons in a time-sharing manner under the control of the control device by using only a single pulse power source 1.

Fig. 7 is a graph of the timing of the operation of the major components of the multiple energy frequency doubling electron linac shown in fig. 6 and the relative intensities of the generated voltages, currents, microwave powers or electron beam energies. Similar to fig. 2, the number of different energies output by the accelerator is the same as the number of microwave power sources, and the operating frequency of the accelerator can be multiple of that of a single microwave power source accelerator.

Fig. 8 is a timing diagram of the multi-energy frequency-doubled electron linac shown in fig. 6 in the case of operating in the single-energy mode. In this mode, the power of each microwave power source is the same, the output high voltage of the electron gun power source is the same at each moment, and the accelerator outputs electron beams with single energy, but the electron beam power of the accelerator is n times that of the accelerator with a single microwave power source. Such an accelerator can be applied in situations where energy spreading is not required, only power spreading is required.

Although embodiments of the present invention have been described above using an electron linac as an example, one of ordinary skill in the art will recognize that the present invention may also be used to accelerate other particles.

While certain features of the invention have been illustrated and described, it will be appreciated that many modifications, substitutions, changes and equivalents will now occur to those skilled in the art, within the scope of the appended claims.

Claims (13)

1. A multi-energy frequency-doubled particle accelerator, comprising:

the pulse power generation unit is used for generating N pulse signals with different powers, wherein N is greater than or equal to 2;

n microwave power generating units, under the control of control signals, respectively generating N microwaves with different energies based on the N pulse signals;

a power mixing unit having N inlets and one outlet, for inputting corresponding microwaves of the N microwaves from each inlet of the N inlets, and outputting the N microwaves from the one outlet, respectively;

a particle beam generating unit for generating N electron beams in synchronization with the N microwaves; and

and the accelerating unit is used for accelerating the N electron beams by utilizing the N microwaves respectively.

2. The multiple energy frequency doubling particle accelerator of claim 1, further comprising a single synchronization unit disposed between the power mixing unit and the acceleration unit for synchronizing a characteristic frequency of the acceleration unit and an operating frequency of each of the N microwave power generation units.

3. The multiple energy frequency-doubled particle accelerator of claim 1, further comprising N synchronizing units respectively disposed between the respective microwave power generating units and the power mixing unit, for respectively synchronizing a characteristic frequency of the accelerating unit and an operating frequency of each of the N microwave power generating units.

4. The multiple energy frequency doubling particle accelerator of claim 2, wherein the synchronization unit comprises:

an incident wave sampling waveguide that samples each of the N microwaves output from the one outlet of the power mixing unit to obtain an incident wave;

a circulator which sends each of the N microwaves into the acceleration unit and outputs a corresponding microwave reflected from the acceleration unit;

a reflected wave sampling waveguide for sampling the reflected corresponding microwave to obtain a reflected wave;

the automatic phase-locking frequency stabilizing device compares and analyzes the incident wave and the reflected wave and generates a synchronizing signal for respectively synchronizing the characteristic frequency of the accelerating unit and the working frequency of each of the N microwave power generating units; and

and the absorption load absorbs the reflected wave output by the circulator.

5. The multiple energy frequency doubling particle accelerator of claim 3, wherein each synchronization unit comprises:

an incident wave sampling waveguide that samples microwaves output from the corresponding microwave power generation units to obtain incident waves;

a circulator which sends the microwaves into a power mixing unit and outputs the microwaves reflected from the acceleration unit via the power mixing unit;

a reflected wave sampling waveguide for sampling the reflected microwave to obtain a reflected wave;

the automatic phase-locking frequency stabilizing device compares and analyzes the incident wave and the reflected wave and generates synchronous signals for respectively synchronizing the characteristic frequency of the accelerating unit and the working frequency of the corresponding microwave power generating unit;

and the absorption load absorbs the reflected wave output by the circulator.

6. The multiple energy frequency-doubled particle accelerator of claim 4 or 5, wherein the auto-phase-locked frequency stabilization device comprises:

a variable attenuator for adjusting the amplitudes of the incident wave and the reflected wave and outputting an incident signal and a reflected signal;

the phase discriminator is used for adjusting the phases of the incident signal and the reflected signal and outputting a first voltage and a second voltage;

a preamplifier for amplifying a difference between the first voltage and the second voltage to output an adjustment signal;

the servo amplifier is used for amplifying the adjusting signal and outputting a driving signal;

and the channel selector outputs the driving signal to the corresponding microwave power generation unit under the control of the control signal.

7. The multiple energy frequency-doubled particle accelerator according to any one of claims 1 to 3, wherein the pulsed power generation unit comprises a single pulsed power source that supplies energy to the N microwave power generation units in a time-shared manner under control of a control signal.

8. The multiple energy frequency-doubled particle accelerator according to any one of claims 1 to 3, wherein the pulsed power generation unit comprises N pulsed power sources, which respectively supply energy to the N microwave power generation units at different times under the control of a control signal.

9. The multiple energy frequency doubling particle accelerator according to any one of claims 1 to 3, wherein the particle beam generation unit comprises an electron gun for generating an electron beam and a gun power supply for supplying power to the electron gun.

10. The multiple energy frequency doubling particle accelerator according to any one of claims 1 to 3, wherein the power mixing unit comprises N-1 mixing rings each having two inlets and one outlet, wherein the difference in central arc lengths of the two microwave paths between one inlet and the other inlet is an integer multiple of the guided wave wavelength plus one half of the guided wave wavelength, the difference in central arc lengths of the two microwave paths between the one inlet and the other outlet is an integer multiple of the guided wave wavelength, and the difference in central arc lengths of the two microwave paths between the other inlet and the other outlet is an integer multiple of the guided wave wavelength.

11. A multi-energy frequency-doubled particle accelerator, comprising:

the pulse power generation unit is used for generating N pulse signals with the same power, wherein N is greater than or equal to 2;

n microwave power generating units, under the control of the control signal, respectively generating N microwaves with the same energy based on the N pulse signals;

a power mixing unit having N inlets and one outlet, for inputting corresponding microwaves of the N microwaves from each inlet of the N inlets, and outputting the N microwaves from the one outlet, respectively;

a particle beam generating unit for generating N electron beams in synchronization with the N microwaves; and

and the accelerating unit is used for accelerating the N electron beams by utilizing the N microwaves respectively.

12. A method of accelerating a particle beam, comprising the steps of:

generating N pulse signals with different powers, wherein N is greater than or equal to 2;

under the control of a control signal, respectively generating N microwaves with different energies based on the N pulse signals;

mixing the N microwaves by using a power mixing unit having N inlets to which corresponding microwaves of the N microwaves are input from respective inlets of the N inlets and one outlet from which the N microwaves are output;

generating N electron beams in synchronization with the N microwaves; and

and accelerating the N electron beams by using the N microwaves respectively.

13. A method of accelerating a particle beam, comprising the steps of:

generating N pulse signals with the same power, wherein N is greater than or equal to 2;

under the control of a control signal, respectively generating N microwaves with the same energy based on the N pulse signals;

mixing the N microwaves by using a power mixing unit having N inlets to which corresponding microwaves of the N microwaves are input from respective inlets of the N inlets and one outlet from which the N microwaves are output;

generating N electron beams in synchronization with the N microwaves; and

and accelerating the N electron beams by using the N microwaves respectively.