Drift tube accelerator and frequency modulation method thereof

Abstract

The invention provides a drift tube accelerator and a frequency modulation method thereof, and the frequency modulation method of the drift tube accelerator comprises the steps: obtaining the cavity radius of each resonant cavity when the drift tube accelerator meets an electric field uniformity condition, and obtaining the tuning proportion of the drift tube accelerator when the drift tube accelerator meets the electric field uniformity condition; when the resonant frequency does not reach the target frequency, the cavity radius of each resonant cavity is synchronously adjusted based on the tuning proportion, so that the resonant frequency of the drift tube accelerator reaches the target frequency; according to the invention, the drift tube accelerator can be rapidly and efficiently adjusted to the target frequency, and the uniform state of the electric field of the drift tube accelerator is prevented from being damaged, so that the electric field stability of the particle beam in the acceleration process is improved, and the acceleration effect of the particle beam is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of BNCT, and relates to a drift tube accelerator frequency modulation method, in particular to a drift tube accelerator and a frequency modulation method thereof. Background Art

[0002] A drift tube accelerator is a device for accelerating particle beams such as neutron beams, ion beams or electron beams. Two resonant cavities are coupled through a coupling structure to form an entire accelerating cavity, wherein each resonant cavity includes multiple accelerating gaps. Based on the gap voltage generated by each accelerating gap, an electric field of the corresponding resonant cavity is formed, and the electric field of the drift tube accelerator is formed through coupling through the coupling structure to achieve acceleration of the particle beam.

[0003] In order to meet the working requirements of the drift tube accelerator, during the design stage, it is often necessary to modulate the overall resonant frequency of the drift tube accelerator to the target frequency required for the working state; in the prior art, the frequency modulation design of the drift tube accelerator is usually based on adjusting the cavity radius of each resonant cavity; however, for a drift tube accelerator with a coupled structure, the electric field uniformity of the drift tube accelerator is easily destroyed in the process of adjusting the cavity radius of each resonant cavity respectively, thereby making it difficult for the electric field uniformity of the accelerator to reach the optimal working state, affecting the acceleration effect of the beam.

[0004] Therefore, when designing a drift tube accelerator, how to perform frequency modulation on the drift tube accelerator while ensuring the electric field uniformity of the drift tube accelerator has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The object of the present invention is to provide a drift tube accelerator and a frequency modulation method thereof, so as to solve the technical problem that the electric field uniformity of the drift tube accelerator is destroyed during the frequency modulation process, thereby resulting in poor acceleration effect.

[0006] In a first aspect, the present invention provides a drift tube accelerator, comprising: a first resonant cavity, a second resonant cavity and a coupling unit;

[0007] The coupling unit is located between the first resonant cavity and the second resonant cavity, and is connected with each resonant cavity to form an integral accelerating cavity; the coupling unit, the first resonant cavity and the second resonant cavity are coaxially arranged to form a beam channel of the entire accelerating cavity; a plurality of drift tubes arranged at intervals are provided in the cavity of each resonant cavity; an accelerating gap for accelerating the beam is formed at intervals between two adjacent drift tubes; the drift tube is used to shield the transverse electric field so that a longitudinal electric field for accelerating the particle beam is formed in the accelerating gap.

[0008] In a second aspect, the present invention provides a frequency modulation method applicable to the drift tube accelerator as described above, including: obtaining the cavity radius of each resonant cavity of the drift tube accelerator when the electric field uniformity condition is satisfied, and obtaining the tuning ratio of the drift tube accelerator when the electric field uniformity condition is satisfied; when the resonant frequency has not reached the target frequency, based on the tuning ratio, synchronously adjusting the cavity radius of each of the resonant cavities so that the resonant frequency of the drift tube accelerator reaches the target frequency. Wherein, the electric field uniformity coefficient is a coefficient characterizing the voltage distribution difference between the resonant cavities.

[0009] In some embodiments of the second aspect of the present application, the method for obtaining the tuning ratio includes: obtaining the tuning ability factor corresponding to the first resonant cavity, and obtaining the tuning ability factor corresponding to the second resonant cavity; setting the ratio between the first tuning ability factor and the second tuning ability factor as the tuning ratio. The tuning ratio is the ratio of the tuning ability factor corresponding to the first resonant cavity to the tuning ability factor corresponding to the second resonant cavity. Wherein, the tuning ability factor corresponds to the resonant cavity and is a factor used to characterize the influence of the change in the cavity radius of the current resonant cavity on the change in the resonant frequency of the total cavity in the drift tube accelerator.

[0010] In some embodiments of the second aspect of the present application, the obtaining the tuning ability factor corresponding to the first resonant cavity and obtaining the tuning ability factor corresponding to the second resonant cavity includes: for the first resonant cavity, obtaining a first relationship curve of the resonant frequency of the drift tube accelerator changing with the cavity radius of the first resonant cavity; extracting the slope corresponding to the first relationship curve and taking the absolute value of the slope as the tuning ability factor corresponding to the first resonant cavity; for the second resonant cavity, obtaining a second relationship curve of the resonant frequency of the drift tube accelerator changing with the cavity radius of the second resonant cavity; extracting the slope corresponding to the second relationship curve and taking the absolute value of the slope as the tuning ability factor corresponding to the second resonant cavity.

[0011] In some embodiments of the second aspect of the present application, the synchronously adjusting the cavity radius of each of the resonant cavities based on the tuning ratio includes: judging the magnitude relationship between the resonant frequency and the target frequency; if the resonant frequency is less than the target frequency, then simultaneously reducing the cavity radius of each of the resonant cavities based on the tuning ratio, and the ratio between the reduction amounts of the cavity radii of each of the resonant cavities is equal to the tuning ratio;

[0012] if the resonant frequency is greater than the target frequency, then simultaneously increasing the cavity radius of each of the resonant cavities based on the tuning ratio, and the ratio between the increase amounts of the cavity radii of each of the resonant cavities is equal to the tuning ratio.

[0013] In some embodiments of the second aspect of the present application, before obtaining the tuning ratio of the drift tube accelerator when the electric field uniformity condition is satisfied and the cavity radii of each resonator, the following steps are further included: obtaining the electric field characteristics corresponding to the resonator according to the cavity radii of each resonator in the drift tube accelerator; obtaining the electric field uniformity coefficient of the total cavity based on the electric field characteristics of each resonator; when the electric field uniformity coefficient does not satisfy the electric field uniformity condition, adjusting the cavity radius of the resonator based on the electric field characteristics of each resonator so that the electric field uniformity coefficient of the total cavity satisfies the electric field uniformity condition.

[0014] In some embodiments of the second aspect of the present application, the electric field characteristics include voltage distribution; the electric field uniformity coefficient is the ratio of the voltage distribution of the first resonator to the voltage distribution of the second resonator, and the electric field uniformity condition is that the electric field uniformity coefficient is within a preset ratio range; alternatively, the electric field uniformity coefficient is the difference between the voltage distribution of the first resonator and the voltage distribution of the second resonator, and the electric field uniformity condition is that the electric field uniformity coefficient is within a preset difference range.

[0015] In some embodiments of the second aspect of the present application, the method for obtaining the voltage distribution of the resonator includes: obtaining the gap voltage corresponding to each acceleration gap in the resonator; synthesizing the gap voltages corresponding to each acceleration gap in the resonator to obtain the voltage distribution of the resonator, including: taking the average value of each gap voltage and using this voltage average value as the voltage distribution corresponding to the resonator.

[0016] In a third aspect, the present invention further provides a storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the frequency modulation method of the drift tube accelerator as described above.

[0017] In a fourth aspect, the present invention further provides a terminal, including a processor and a memory, and the memory is communicatively connected to the processor; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory so that the terminal executes the frequency modulation method of the drift tube accelerator as described above.

[0018] As described above, for the drift tube accelerator and its frequency modulation method of the present application, the cavity radii of each resonator are synchronously adjusted based on a preset tuning ratio, thereby ensuring that the electric field uniformity of the drift tube accelerator remains unchanged during the frequency modulation process, and further avoiding poor particle acceleration effects of the drift tube accelerator caused by changes in the cavity radius. This effectively improves the debugging efficiency of the drift tube accelerator before operation. Moreover, the steps of the frequency modulation method of the drift tube accelerator provided in the present application are simple and easy to operate, further improving the debugging efficiency of the drift tube accelerator and facilitating the practical application of the drift tube accelerator. Description of the Drawings

[0019] Figure 1 It shows a schematic structural diagram of the drift tube accelerator described in the embodiment of the present invention;

[0020] Figure 2 It shows a schematic flow diagram of the method for adjusting the electric field uniformity of the drift tube accelerator described in the embodiment of the present invention;

[0021] Figure 3 It shows a schematic flow diagram of the method for obtaining the voltage distribution of the resonant cavity described in the embodiment of the present invention;

[0022] Figure 4 It shows a schematic flow diagram of the process for adjusting the cavity radius of the resonant cavity described in the embodiment of the present invention;

[0023] Figure 5 It shows a schematic flow diagram of the frequency modulation method of the drift tube accelerator described in the embodiment of the present invention;

[0024] Figure 6 It shows a schematic flow diagram of the method for obtaining the tuning ratio described in the embodiment of the present invention;

[0025] Figure 7 It shows a schematic diagram of the curve distribution of the first relationship curve and the second relationship curve described in the embodiment of the present invention;

[0026] Figure 8 It shows a schematic flow diagram of the method for obtaining the target radius of the resonant cavity of the present invention in one embodiment;

[0027] Figure 9 It shows a schematic structural diagram of an electronic terminal described in the embodiment of the present invention;

[0028] Explanation of reference numerals

[0029] C1 - First resonant cavity; C2 - Second resonant cavity; C3 - Coupling unit; 31 - Electric field uniformity acquisition module; 32 - Electric field uniformity determination module; 41 - Cavity radius acquisition module; 42 - Resonant frequency acquisition module; 43 - Resonant frequency determination module; 50 - Electronic terminal; 51 - Processor; 52 - Memory; 53 - Network interface; 54 - User interface; 55 - Bus system; 521 - Operating system; 522 - Application program. Detailed implementation manners

[0030] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0031] The principle and implementation of the drift tube accelerator and its frequency modulation method in this embodiment will be elaborated in detail below, so that those skilled in the art can understand the drift tube accelerator and its frequency modulation method in this embodiment without creative work.

[0032] The acceleration effect of the drift tube accelerator on the particle beam is closely related to the electric field distribution in the accelerator; when the electric field distribution of the drift tube accelerator is uneven, it will cause the energy gain of the particle beam to be inconsistent during the acceleration process, that is, the acceleration state of the particle beam is unstable, and further result in poor acceleration effect of the particle beam. Based on this, the embodiment of the present invention first provides a method for adjusting the electric field uniformity of the drift tube accelerator to adjust the electric field uniformity of the drift tube accelerator so that the electric field uniformity meets the working requirements of the drift tube accelerator.

[0033] Wherein, the drift tube accelerator is an accelerator using a coupling structure, that is, the drift tube accelerator includes a first resonant cavity and a second resonant cavity connected in a coupling manner.

[0034] Please refer to Figure 1 , which shows the structural schematic diagram of the drift tube accelerator in an embodiment. As Figure 1 shown, the drift tube accelerator includes: a first resonant cavity C1, a second resonant cavity C2, and a coupling unit C3; the coupling unit C3 is located between the first resonant cavity C1 and the second resonant cavity C2, and is connected to each resonant cavity to form an integral acceleration cavity to realize the physical field coupling of the first resonant cavity C1 and the second resonant cavity C2; the coupling unit C3, the first resonant cavity C1, and the second resonant cavity C2 are coaxially arranged to form a beam channel of the entire acceleration cavity, so that the particle beam passes through the drift tube accelerator from the beam channel, avoiding the deflection of the movement direction of the particle beam.

[0035] Inside the cavity of each of the resonant cavities, a plurality of drift tubes arranged at intervals are provided; between two adjacent drift tubes, acceleration gaps for accelerating the beam are formed at intervals; the drift tubes are used to shield the transverse electric field so that a longitudinal electric field is formed in the acceleration gaps, enabling the particle beam to be accelerated at each of the acceleration gaps; and, each of the drift tubes is coaxially arranged and a drift tube through-hole is provided in the axial portion; each of the drift tube through-holes is communicated with the coupling through-holes in the coupling unit to jointly form the beam channel.

[0036] The drift tube accelerator accelerates particle beams such as neutron beams, ion beams or electron beams, and outputs high-speed particle beams for medical or other uses.

[0037] When the electric field distribution of each resonant cavity is uneven, it will cause the energy gain of the particle beam to be inconsistent during the acceleration process, further increasing the instability of the particle beam and resulting in poor acceleration effect of the particle beam.

[0038] To ensure the acceleration effect of the particle beam, the method for adjusting the electric field uniformity of the drift tube accelerator provided in the embodiments of the present invention is as Figure 2 shown, and includes the following steps:

[0039] S100, according to the cavity radius of each resonant cavity in the drift tube accelerator, obtain the electric field characteristics corresponding to the resonant cavity; based on the electric field characteristics of each resonant cavity, obtain the electric field uniformity coefficient of the total cavity;

[0040] Wherein, the cavity radius is the radial distance from the cavity center to the cavity edge in a plane perpendicular to the beam channel.

[0041] The electric field uniformity coefficient is a coefficient used to characterize the similarity / difference degree of the electric field characteristics between the resonant cavities.

[0042] The electric field characteristics of each resonant cavity are used to characterize the electric field state of each resonant cavity; exemplarily, the electric field characteristics of each resonant cavity include but are not limited to electric field physical characteristics such as voltage distribution and electric field intensity distribution of each resonant cavity.

[0043] For ease of understanding, the following specific embodiments will take the voltage distribution as the electric field characteristic of the resonant cavity to illustrate the implementation manner of step S100; those skilled in the art can know that in other specific embodiments, the electric field intensity distribution can also be used as the electric field characteristic of the resonant cavity to execute step S100.

[0044] Specifically, when step S100 is executed, it includes;

[0045] Based on the cavity radius size of the first resonant cavity, obtaining a voltage distribution corresponding to the first resonant cavity; and based on the cavity radius size of the second resonant cavity, obtaining a voltage distribution corresponding to the second resonant cavity;

[0046] Based on the voltage distribution of each resonant cavity, a coefficient for characterizing the difference in voltage distribution between the resonant cavities is constructed as an electric field uniformity coefficient.

[0047] In an optional embodiment, the electric field uniformity is the ratio of the voltage distribution between the resonant cavities, so as to characterize the degree of voltage difference between the resonant cavities based on the size of the ratio; illustratively, the expression of the electric field uniformity coefficient is:

[0048]

[0049] Wherein, k represents the electric field uniformity coefficient, V1 represents the voltage distribution of the first resonant cavity C1, and V2 represents the voltage distribution of the second resonant cavity C2. The closer the k value is to 1, the smaller the difference in the voltage distribution of the resonant cavities is, that is, the more uniform the electric field distribution is; on the contrary, the greater the difference between the k value and 1, the greater the difference in the voltage distribution of the resonant cavities is, that is, the worse the uniformity of the electric field distribution is.

[0050] In another optional embodiment, the electric field uniformity is the difference in voltage distribution between the resonant cavities, so as to characterize the degree of voltage difference between the resonant cavities based on the size of the difference; illustratively, the expression of the electric field uniformity coefficient is:

[0051] k=V1-V2

[0052] The closer the k value is to 0, the smaller the difference in voltage distribution of the resonant cavities is, that is, the more uniform the electric field distribution is; conversely, the greater the difference between the k value and 0, the greater the difference in voltage distribution of the resonant cavities is, that is, the worse the uniformity of the electric field distribution is.

[0053] It should be noted that the voltage distribution mentioned above is a characteristic parameter used to characterize the central tendency of the voltage data in the cavity; illustratively, the voltage distribution includes the voltage mean, median or other existing characteristic values that characterize the central tendency of the data set.

[0054] Since a single resonant cavity is provided with a plurality of accelerating gaps, in order to more accurately and objectively characterize the voltage distribution corresponding to each resonant cavity, the voltage distribution of the resonant cavity is obtained in a manner such as: Figure 3 As shown, including:

[0055] S101, obtaining the gap voltage corresponding to each accelerating gap in the resonant cavity;

[0056] Specifically, extract the structural parameters corresponding to each acceleration gap in the resonant cavity; input the structural parameters into an accelerator simulation platform, and use the simulation platform to perform simulation calculations on the structural parameters to obtain the gap voltage corresponding to the acceleration gap.

[0057] Among them, the structural parameters include the drift tube length, the acceleration gap length, the acceleration period length, etc.

[0058] It should be noted that in this application, the parameter values corresponding to the structural parameters are all pre-determined values.

[0059] Exemplarily, the simulation platform is CST software.

[0060] S102, synthesize the gap voltages corresponding to each acceleration gap in the resonant cavity to obtain the voltage distribution of the resonant cavity.

[0061] Specifically, for each resonant cavity, after obtaining the gap voltages corresponding to each acceleration gap in the resonant cavity, take the average value of each gap voltage, and use this voltage average value as the voltage distribution corresponding to the resonant cavity, that is:

[0062]

[0063] Among them, V I represents the average gap voltage of the I-th resonant cavity, n l represents the number of acceleration gaps in the resonant cavity, and v i represents the voltage value of the i-th acceleration gap.

[0064] It should be noted that the above content of this application exemplarily gives a specific acquisition method for the voltage distribution corresponding to each resonant cavity, but is not limited thereto, as long as it can obtain the voltage distribution condition used to characterize each resonant cavity, for example, it can be obtained by direct calculation.

[0065] S200, determine whether the electric field uniformity meets the preset electric field uniformity condition. If not, adjust the cavity radius of the resonant cavity based on the electric field characteristics of each resonant cavity so that the electric field uniformity coefficient of the total cavity meets the electric field uniformity condition;

[0066] Among them, the electric field uniformity condition is the state condition when the electric field uniformity of the drift tube accelerator meets the working requirements of the drift tube accelerator.

[0067] In this application, the electric field uniformity condition is that the electric field uniformity coefficient is within the threshold interval of the electric field difference.

[0068] Exemplarily, when the electric field uniformity coefficient is the ratio between the voltage distributions of the respective resonant cavities, the electric field uniformity condition is that the electric field uniformity coefficient is within a preset ratio range; exemplarily, the ratio range is 0.95±0.005. That is, if the electric field uniformity coefficient is within this ratio range, it indicates that the similarity degree of the electric field characteristics between the respective resonant cavities is relatively high, and it is determined that the electric field uniformity meets the preset electric field uniformity condition; if the electric field uniformity coefficient exceeds this ratio range, it indicates that the similarity degree of the electric field characteristics between the respective resonant cavities is relatively low, and it is determined that the electric field uniformity does not meet the preset electric field uniformity condition.

[0069] It should be noted that when the electric field uniformity coefficient is the difference between the voltage distributions of the respective resonant cavities, correspondingly, the electric field uniformity condition is that the electric field uniformity coefficient is within a preset difference range, which will not be elaborated here.

[0070] Specifically, after obtaining the electric field uniformity coefficient of the drift tube accelerator, it is determined whether the electric field uniformity coefficient meets the preset electric field uniformity condition; if it meets, the electric field uniformity adjustment of the drift tube accelerator is exited; if it does not meet, according to the current electric field characteristics of each resonant cavity, the size of the cavity radius of the first resonant cavity and / or the second resonant cavity is adjusted, so as to re-execute the above steps S100 to S200 based on the drift tube accelerator with the adjusted cavity radius until the updated electric field uniformity coefficient meets the preset electric field uniformity condition.

[0071] The method provided by the embodiments of the present application determines the electric field uniformity of the drift tube accelerator. When the electric field uniformity does not meet the preset condition requirements, the cavity radius of the drift tube accelerator is adjusted to enable the drift tube accelerator to meet the electric field requirements during the operation of the drift tube accelerator. Moreover, the method steps for the electric field uniformity adjustment of the drift tube accelerator provided in this embodiment are simple and easy to operate, realizing the fast and convenient adjustment of the electric field uniformity of the drift tube accelerator, effectively improving the adjustment efficiency of the drift tube accelerator, and being beneficial to the practical application of the drift tube accelerator.

[0072] To improve the efficiency of the electric field uniformity adjustment, the process of adjusting the cavity radius of the resonant cavity is as Figure 4 shown and includes:

[0073] S201, obtaining the electric field intensity distribution of each of the resonant cavities, and based on the electric field intensity distribution of the resonant cavities, dividing each of the resonant cavities into a high electric field distribution cavity and a low electric field distribution cavity;

[0074] Among them, the electric field intensity distribution is a characteristic value representing the electric field intensity distribution characteristics in the resonant cavity, including but not limited to the mean value, median value, etc.

[0075] S202, based on a preset radius adjustment amount, increasing the cavity radius of the low electric field distribution cavity and / or reducing the cavity radius of the high electric field distribution cavity, so that the electric field strength of the low electric field distribution cavity increases after adjustment, and / or the electric field strength of the high electric field distribution cavity decreases after adjustment, thereby making the electric field strength distribution of each of the resonant cavities tend to be the same.

[0076] The radius adjustment amount is a preset radius adjustment size, which is used as the radius adjustment step of the resonant cavity; illustratively, if the cavity radius of each resonant cavity is 320 mm, the preset length is 1 mm.

[0077] Those skilled in the art may appreciate that, in other specific embodiments, the voltage distribution may also be used as the electric field characteristic of the resonant cavity to perform cavity radius adjustment of the resonant cavity, and the adjustment process is the same as the above-mentioned adjustment process and will not be described in detail here.

[0078] In order to meet the working requirements of the drift tube accelerator, during the design stage, it is often necessary to modulate the overall resonant frequency of the drift tube accelerator to the target frequency required for the working state; specifically, in the prior art, the frequency modulation design of the drift tube accelerator is usually based on adjusting the cavity radius of the resonant cavity; however, for the drift tube accelerator with a coupled structure, the electric field uniformity of the drift tube accelerator is easily destroyed in the process of adjusting the cavity radius of each resonant cavity respectively, thereby making it difficult for the electric field uniformity of the accelerator to reach the optimal working state, affecting the acceleration effect of the beam.

[0079] To solve the above problem, the present application further provides a frequency modulation method for a drift tube accelerator in a second aspect, which is used to reduce the influence of the frequency modulation process on the uniformity of the electric field in the drift tube accelerator during the frequency modulation process of the drift tube accelerator.

[0080] See also Figure 5 , showing the frequency modulation method of the drift tube accelerator provided in an embodiment of the present invention, comprising the following steps:

[0081] S10, obtaining the cavity radius of each resonant cavity of the drift tube accelerator when the electric field uniformity condition is satisfied, and obtaining the tuning ratio of the drift tube accelerator when the electric field uniformity condition is satisfied;

[0082] The electric field uniformity condition is a state condition when the electric field uniformity of the drift tube accelerator meets the working requirements of the drift tube accelerator.

[0083] Specifically, the electric field uniformity coefficient of the drift tube accelerator is adjusted by using the electric field homogenization adjustment method described above, so that the electric field uniformity coefficient of the drift tube accelerator meets the preset electric field uniformity condition; when the electric field uniformity condition is met, the cavity radius of each resonator in the drift tube accelerator is extracted as the cavity radius of each resonator in the drift tube accelerator when the electric field uniformity condition is met.

[0084] S20. When the resonance frequency does not reach the target frequency, based on the tuning ratio, the cavity radii of the resonators are synchronously adjusted so that the resonance frequency of the drift tube accelerator reaches the target frequency.

[0085] Wherein, the target frequency is the resonance frequency required for the drift tube accelerator to achieve the target particle beam intensity.

[0086] The tuning ratio is the ratio between the radius adjustment amounts corresponding to the resonators, and is used to realize the synchronous change of the electric field characteristics of the resonators during the tuning process.

[0087] Specifically, the current resonance frequency of the drift tube accelerator is obtained, and the magnitude relationship between the resonance frequency and the target frequency is judged. If the resonance frequency is less than the target frequency, the cavity radii of the resonators are simultaneously reduced based on the preset tuning ratio, and the ratio between the reduction amounts of the cavity radii of the resonators is equal to the tuning ratio; if the resonance frequency is greater than the target frequency, the cavity radii of the resonators are simultaneously increased based on the preset ratio, and the ratio between the increase amounts of the cavity radii of the resonators is equal to the tuning ratio.

[0088] Those skilled in the art can know that the target resonance frequency can be a preset frequency range or a preset frequency value.

[0089] In this embodiment, the cavity radii of the resonators are synchronously adjusted based on the preset tuning ratio, thereby ensuring that the electric field uniformity of the drift tube accelerator remains unchanged during the frequency modulation process, and further avoiding the poor particle acceleration effect of the drift tube accelerator caused by the change of the cavity radius, effectively improving the debugging efficiency of the drift tube accelerator before operation. Moreover, the frequency modulation method of the drift tube accelerator provided in this application has simple steps and is easy to operate, further improving the debugging efficiency of the drift tube accelerator and being conducive to the practical application of the drift tube accelerator.

[0090] In some alternative embodiments, in order to improve the stability of the electric field uniformity of the drift tube accelerator during the frequency modulation process, it is necessary to obtain a more accurate tuning ratio. Based on this, as Figure 6 shown, the method for obtaining the tuning ratio includes:

[0091] S21, obtain the tuning ability factor corresponding to the first resonator and the tuning ability factor corresponding to the second resonator;

[0092] Wherein, the tuning ability factor corresponds to the resonator and is used to characterize the factor that the change of the cavity radius of the current resonator affects the resonance frequency of the total cavity in the drift tube accelerator.

[0093] Specifically, for the first resonator, only change the cavity radius of this resonator (keep the cavity radius of the second resonator unchanged), and obtain the first relationship curve of the resonance frequency of the drift tube accelerator changing with the cavity radius of the first resonator; extract the slope corresponding to the first relationship curve, and take the absolute value of the slope as the tuning ability factor corresponding to the first resonator.

[0094] Similarly, for the second resonator, only change the cavity radius of this resonator (keep the cavity radius of the first resonator unchanged), and obtain the second relationship curve of the resonance frequency of the drift tube accelerator changing with the cavity radius of the second resonator; extract the slope corresponding to the second relationship curve, and take the absolute value of the slope as the tuning ability factor corresponding to the second resonator.

[0095] Wherein, the slope is the slope of the fitting diagonal line obtained after performing linear fitting on the relationship curve; it should be noted that in some other embodiments, the slope as described above can also be the slope of the diagonal line constructed by the two end points in the corresponding relationship curve, or the mean or median value of the tangent slopes corresponding to each curve point in the corresponding relationship curve.

[0096] Exemplarily, the curve distributions of the first relationship curve and the second relationship curve are specifically as Figure 7 shown; it can be seen from Figure 7 that the tuning ability factor corresponding to the first resonator C1 is about 0.12; the tuning ability factor corresponding to the second resonator C2 is about 0.4.

[0097] S22, set the ratio between the first tuning ability factor and the second tuning ability factor as the tuning ratio.

[0098] Exemplarily, when the first relationship curve corresponding to the first resonator C1 and the second relationship curve corresponding to the second resonator C2 are as Figure 7 shown, the tuning ratio is the ratio of the tuning ability factor corresponding to the first resonator C1 to the tuning ability factor corresponding to the second resonator C2, which is 1:3.33.

[0099] When frequency - modulating the drift - tube accelerator, in order to avoid destroying its electric - field uniformity, a tuning ratio of 1:3.33 is adopted to synchronously adjust the cavity radius of the first resonator C1 and the cavity radius of the second resonator C2; that is, when the cavity radius of the first resonator C1 decreases by 1 mm, the cavity radius of the second resonator C2 decreases by 3.33 mm; when the cavity radius of the first resonator C1 increases by 1 mm, the cavity radius of the second resonator C2 increases by 3.33 mm.

[0100] In some alternative embodiments, the resonant frequencies corresponding to multiple cavity radii of each resonator can be obtained through simulation calculation or experiments to obtain a relationship curve; among them, the simulation calculation can be implemented through electromagnetic - field simulation software, such as CST software.

[0101] The method provided in this embodiment obtains the tuning - ability factor corresponding to each resonator by constructing a change - relationship curve between the resonant frequency of the accelerator and the cavity radius, and constructs a tuning ratio based on the tuning - ability factor corresponding to each resonator, so that the constructed tuning ratio can accurately and objectively characterize the influence of the cavity radius of each resonator on the resonant frequency of the accelerator. Thus, the accuracy of the tuning ratio can be effectively improved, while ensuring the electric - field uniformity during the frequency - modulation process of the accelerator and improving the stability of the electric field.

[0102] To solve the above - mentioned technical problems in the prior art, an embodiment of the present invention further provides a method for obtaining the target radius of a resonator, which is used to obtain the target radius corresponding to each resonator when the drift - tube accelerator is tuned to the target frequency.

[0103] In this embodiment, the method for obtaining the target radius of the resonator is as Figure 8 shown and includes:

[0104] S301, according to the first cavity radius of each resonator in the drift - tube accelerator, obtain the electric - field characteristics corresponding to the resonator;

[0105] Among them, the first cavity radius is the cavity radius corresponding to each resonator when the drift - tube accelerator does not meet the electric - field uniformity condition.

[0106] Exemplarily, the first cavity radius is the initial radius value preset for each resonator.

[0107] In this embodiment, the implementation manner of step S301 is the same as the implementation manner of obtaining the electric - field characteristics corresponding to the resonator according to the cavity radius of each resonator in the above - mentioned embodiment, and will not be elaborated here.

[0108] S302. Based on the electric field characteristics of each of the resonant cavities, adjust the first cavity radius of the resonant cavity so that the electric field uniformity coefficient of the total cavity meets the electric field uniformity condition;

[0109] In this embodiment, the implementation manner of step S302 is the same as the implementation manner of the above-mentioned embodiment for performing the cavity radius adjustment process of the resonant cavity based on the electric field characteristics of each resonant cavity, and will not be elaborated here.

[0110] S303. Obtain the tuning ratio of the drift tube accelerator when the electric field uniformity condition is met and the second cavity radius of each resonant cavity;

[0111] Wherein, the second cavity radius is the cavity radius corresponding to each of the resonant cavities when the electric field uniformity condition is met;

[0112] The tuning ratio is the ratio between the radius adjustment amounts corresponding to each resonant cavity, and is used to realize the synchronous change of the electric field characteristics of each resonant cavity during the tuning process.

[0113] In this embodiment, the implementation manner of step S303 is the same as the implementation manner of the above-mentioned embodiment for obtaining the cavity radius of each resonant cavity of the drift tube accelerator when the electric field uniformity condition is met and obtaining the tuning ratio of the drift tube accelerator when the electric field uniformity condition is met, and will not be elaborated here.

[0114] S304. Based on the tuning ratio, synchronously adjust the second cavity radius of each of the resonant cavities so that the resonant frequency of the drift tube accelerator reaches the target frequency;

[0115] In this embodiment, the implementation manner of step S303 is the same as the implementation manner of the above-mentioned embodiment for synchronously adjusting the cavity radius of each of the resonant cavities based on the tuning ratio so that the resonant frequency of the drift tube accelerator reaches the target frequency, and will not be elaborated here.

[0116] S305. Set the second cavity radius corresponding to each of the resonant cavities when the target frequency is reached as the target radius corresponding to the resonant cavity.

[0117] The method for obtaining the target radius of the resonant cavity provided in this embodiment first adjusts the electric field uniformity coefficient of the drift tube accelerator to meet the electric field uniformity condition by using the electric field homogenization adjustment method of the drift tube accelerator, and then combines the frequency modulation method of the drift tube accelerator to adjust the frequency of the drift tube accelerator to the target frequency, so that the target radius corresponding to each resonant cavity of the drift tube accelerator when the target frequency is reached can be obtained quickly and accurately, effectively improving the acquisition efficiency of the cavity radius corresponding to the target frequency.

[0118] The method for obtaining the target radius of the resonant cavity provided in this embodiment can quickly and accurately obtain the target radius corresponding to each resonant cavity of the drift tube accelerator when the drift tube accelerator reaches the target frequency by using the frequency modulation method of the drift tube accelerator to adjust the frequency of the drift tube accelerator to the target frequency.

[0119] Based on the same inventive concept, the method for adjusting the electric field uniformity of the drift tube accelerator, or the method for frequency modulation of the drift tube accelerator, or the method for obtaining the target radius of the resonant cavity provided in the above embodiments of the present invention can be implemented on the terminal side or the server side.

[0120] Please refer to Figure 9 , which is an optional schematic hardware structure diagram of the electronic terminal 50 provided in the embodiment of the present invention. The electronic terminal 50 can be a live broadcast machine, a camera, a mobile phone, a computer device, a tablet device, a personal digital processing device, a factory background processing device, etc. that integrates photo-taking / video-recording functions. The electronic terminal 50 includes: at least one processor 51, a memory 52, at least one network interface 53, and a user interface 54. Each component in the device is coupled together through a bus system 55. It can be understood that the bus system 55 is used to realize the connection and communication between these components. In addition to the data bus, the bus system 55 also includes a power bus, a control bus, and a status signal bus.

[0121] Among them, the user interface 54 may include a display, a keyboard, a mouse, a trackball, a click gun, a key, a button, a touchpad, or a touch screen, etc.

[0122] It can be understood that the memory 52 can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM, Read Only Memory), a programmable read-only memory (PROM, Programmable Read-Only Memory), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM, Static Random Access Memory), synchronous static random access memory (SSRAM, Synchronous Static Random Access Memory). The memory described in the embodiments of the present invention is intended to include but not be limited to these and any other suitable categories of memory.

[0123] The memory 52 in the embodiments of the present invention is used to store various types of data to support the operation of the electronic terminal 50. Examples of such data include: any executable programs for operations on the electronic terminal 50, such as the operating system 521 and application programs 522; the operating system 521 includes various system programs, such as the framework layer, core library layer, driver layer, etc., for implementing various basic services and processing hardware-based tasks. The application programs 522 may include various application programs, such as a MediaPlayer, a Browser, etc., for implementing various application services. The method for adjusting the electric field uniformity of the drift tube accelerator in the embodiments of the present invention, or the frequency modulation method of the drift tube accelerator, or the method for obtaining the target radius of the resonant cavity may be included in the application program 522.

[0124] The methods disclosed in the above embodiments of the present invention can be applied to the processor 51 or implemented by the processor 51. The processor 51 may be an integrated circuit chip with signal processing capabilities. During implementation, the steps of the above methods can be completed through the integrated logic circuit of the hardware in the processor 51 or instructions in software form. The above-mentioned processor 51 may be a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 51 can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor 51 may be a microprocessor or any conventional processor, etc. Combining the steps of the accessory optimization method provided in the embodiments of the present invention can be directly embodied as being completed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium, and this storage medium is located in the memory. The processor reads the information in the memory and combines its hardware to complete the steps of the foregoing method.

[0125] In an exemplary embodiment, the electronic terminal 50 may be one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs) for executing the foregoing methods.

[0126] An embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the program is called by a processor, it implements the method for adjusting the electric field uniformity of the drift tube accelerator provided by the present invention, or the frequency modulation method of the drift tube accelerator, or the method for obtaining the target radius of the resonant cavity.

[0127] Among them, a computer-readable storage medium can be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium can be, for example (but not limited to), an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memories (RAMs), read-only memories (ROMs), erasable programmable read-only memories (EPROMs or flash memories), static random access memories (SRAMs), portable compact disk read-only memories (CD-ROMs), digital versatile disks (DVDs), memory sticks, floppy disks, and mechanical encoding devices.

[0128] The computer-readable programs described herein can be downloaded from the computer-readable storage medium to various computing / processing devices, or downloaded to an external computer or external storage device through a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network adapter or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0129] It should be noted that in various embodiments of the present application, the sequence numbers of the above steps do not represent the order of execution. The execution order of each step should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0130] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A drift tube accelerator, characterized in that, Comprising: A first resonant cavity, a second resonant cavity, and a coupling unit; The coupling unit is located between the first resonant cavity and the second resonant cavity, and is connected to each resonant cavity to form an integral accelerating cavity; The coupling unit, the first resonant cavity, and the second resonant cavity are coaxially arranged to form a beam channel of the entire accelerating cavity; Inside the cavity of each resonant cavity, a plurality of drift tubes are arranged at intervals; between two adjacent drift tubes, accelerating gaps for accelerating the beam are formed at intervals; the drift tubes are used to shield the transverse electric field so that a longitudinal electric field for accelerating the particle beam is formed in the accelerating gaps.

2. A frequency modulation method applicable to the drift tube accelerator as claimed in claim 1, comprising: Obtaining the cavity radius of each resonant cavity when the drift tube accelerator satisfies the electric field uniformity condition, and obtaining the tuning ratio when the drift tube accelerator satisfies the electric field uniformity condition; When the resonant frequency does not reach the target frequency, based on the tuning ratio, synchronously adjusting the cavity radius of each resonant cavity so that the resonant frequency of the drift tube accelerator reaches the target frequency; Wherein, the electric field uniformity coefficient is a coefficient characterizing the voltage distribution difference between the resonant cavities.

3. The method according to claim 2, wherein The method for obtaining the tuning ratio includes: Obtaining the tuning ability factor corresponding to the first resonant cavity, and obtaining the tuning ability factor corresponding to the second resonant cavity; The tuning ratio is the ratio of the tuning ability factor corresponding to the first resonant cavity to the tuning ability factor corresponding to the second resonant cavity; Wherein, the tuning ability factor corresponds to the resonant cavity and is a factor for characterizing the influence of the change in the cavity radius of the current resonant cavity on the change in the resonant frequency of the total cavity in the drift tube accelerator.

4. The method according to claim 3, characterized in that, The obtaining the tuning ability factor corresponding to the first resonant cavity, and obtaining the tuning ability factor corresponding to the second resonant cavity, includes: For the first resonant cavity, obtaining a first relationship curve of the resonant frequency of the drift tube accelerator changing with the cavity radius of the first resonant cavity; extracting the slope corresponding to the first relationship curve, and taking the absolute value of the slope as the tuning ability factor corresponding to the first resonant cavity; For the second resonant cavity, obtaining a second relationship curve of the resonant frequency of the drift tube accelerator changing with the cavity radius of the second resonant cavity; extracting the slope corresponding to the second relationship curve, and taking the absolute value of the slope as the tuning ability factor corresponding to the second resonant cavity.

5. The method according to claim 2, wherein The synchronously adjusting the cavity radius of each resonant cavity based on the tuning ratio includes: Judging the magnitude relationship between the resonant frequency and the target frequency; if the resonant frequency is less than the target frequency, then simultaneously reducing the cavity radius of each resonant cavity based on the tuning ratio, and the ratio of the reduction amounts of the cavity radii of each resonant cavity is equal to the tuning ratio; If the resonant frequency is greater than the target frequency, then simultaneously increasing the cavity radius of each resonant cavity based on the tuning ratio, and the ratio of the increase amounts of the cavity radii of each resonant cavity is equal to the tuning ratio.

6. The method according to claim 2, characterized in that, Before obtaining the tuning ratio of the drift tube accelerator when the electric field uniformity condition is satisfied and the cavity radius of each resonator, the following steps are also included: Based on the cavity radius of each resonator in the drift tube accelerator, obtain the electric field characteristics corresponding to the resonator; Based on the electric field characteristics of each resonator, obtain the electric field uniformity coefficient of the total cavity; When the electric field uniformity coefficient does not meet the electric field uniformity condition, based on the electric field characteristics of each resonator, adjust the cavity radius of the resonator so that the electric field uniformity coefficient of the total cavity meets the electric field uniformity condition.

7. The method according to claim 6, wherein The electric field characteristics include voltage distribution; The electric field uniformity coefficient is the ratio of the voltage distribution of the first resonator to the voltage distribution of the second resonator, and the electric field uniformity condition is that the electric field uniformity coefficient is within a preset ratio range; Alternatively, the electric field uniformity coefficient is the difference between the voltage distribution of the first resonator and the voltage distribution of the second resonator, and the electric field uniformity condition is that the electric field uniformity coefficient is within a preset difference range.

8. The method according to claim 7, characterized in that The method for obtaining the voltage distribution of the resonator includes: Obtain the gap voltage corresponding to each acceleration gap in the resonator; Integrate the gap voltages corresponding to each acceleration gap in the resonator to obtain the voltage distribution of the resonator, including: Take the average value of each gap voltage and use this voltage average value as the voltage distribution corresponding to the resonator.

9. A storage medium, on which a computer program is stored, characterized in that, When the program is executed by a processor, it implements the frequency modulation method of the drift tube accelerator according to any one of claims 2 to 8.

10. A terminal, characterized in that, It includes a processor and a memory, and the memory is communicatively connected to the processor; the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory so that the terminal executes the frequency modulation method of the drift tube accelerator according to any one of claims 2 to 8.

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