A particle accelerator electrode load matching system and method

Abstract

The present invention discloses a particle accelerator electrode load matching system and method, belonging to the field of particle acceleration, including: a signal generator for generating fundamental wave, second harmonic, and third harmonic signals, and simultaneously completing the control of the amplitude and phase of the signals; a power amplifier connected to the signal generator for amplifying the signals; a matching sampling circuit connected to the power amplifier and the signal generator for achieving impedance matching between the power amplifier and the bunching electrode, so that the power signal of the power amplifier generates a sufficiently large bunching voltage on the bunching electrode. The present invention designs a matching sampling circuit to achieve impedance matching between the power amplifier and the bunching electrode, so that the power signal of the power amplifier generates a sufficiently large bunching voltage on the bunching electrode. At the same time, the internal sampling circuit realizes real-time feedback sampling of the signal and sends this sampling signal to the signal generator to dynamically realize the closed-loop of feedback control.

Description

Technical Field

[0001] The present invention relates to the field of particle acceleration, and specifically to a particle accelerator electrode load matching system and method. Background Art

[0002] A particle accelerator, whose full name is "charged particle accelerator", is a special electromagnetic and high-vacuum device that enables charged particles to be controlled by magnetic force and accelerated by electric force in a high-vacuum field to achieve high energy. It is a device that artificially provides various high-energy particle beams.

[0003] Particle accelerators are not only widely used in basic scientific and applied scientific research. At the same time, they also play an important role in the industrial field.

[0004] In an accelerator, in order to longitudinally focus the ion beam on the beam transport line and improve the beam current intensity and quality, a bunching device needs to be used. Adopting a sawtooth waveform design is a method to improve the bunching performance;

[0005] An ideal sawtooth wave contains rich harmonic components. In actual engineering design, more engineering factors need to be considered. At the same time, there must be a certain assessment measure for the distortion of the sawtooth wave, rather than the negative impact on the system indicators brought by the completely ideal sawtooth wave.

[0006] Therefore, at present, how to provide a sawtooth wave generation waveform that meets the requirements of bunching is a problem that needs to be solved currently. Summary of the Invention

[0007] Object of the Invention: To provide a particle accelerator electrode load matching system and method to solve the above problems existing in the prior art.

[0008] Technical Solution: A particle accelerator electrode load matching system includes:

[0009] A signal generator, which is used to generate fundamental wave, second harmonic, and third harmonic signals, and at the same time complete the control of the amplitude and phase of the signals;

[0010] A power amplifier, which is connected to the signal generator and is used to amplify the signals;

[0011] A matching sampling circuit, which is connected to the power amplifier and the signal generator, and is used to achieve impedance matching between the power amplifier and the bunching electrode, so that the power signal of the power amplifier generates a sufficient large bunching voltage on the bunching electrode;

[0012] A vacuum chamber, which is connected to the matching sampling circuit;

[0013] A bunching electrode, which is arranged in the vacuum chamber and is connected to the matching sampling circuit.

[0014] The present invention designs a matching sampling circuit to achieve impedance matching between a power amplifier and a bunching electrode, enabling the power signal of the power amplifier to generate a sufficiently large bunching voltage on the bunching electrode. Meanwhile, the internal sampling circuit realizes real-time feedback sampling of the signal and sends this sampled signal to a signal generator to dynamically implement a closed loop of feedback control;

[0015] The control software in the signal generator can adjust the amplitude and phase of the output signal according to the amplitude and phase information of the sampled signal obtained in real time, so as to meet the requirements of the sawtooth wave generation waveform for bunching.

[0016] In a further embodiment, the sampling circuit inside the matching sampling circuit realizes real-time feedback sampling of the signal, sends the sampled signal to the signal generator, dynamically implements a closed loop of feedback control, and the control software in the signal generator adjusts the amplitude and phase of the output signal according to the amplitude and phase information of the sampled signal obtained in real time, so as to meet the requirements of the sawtooth wave generation waveform for bunching.

[0017] In a further embodiment, the matching sampling circuit includes:

[0018] Transformers, all of which are transmission transformers, used to achieve impedance ratio transformation and balance-unbalance conversion;

[0019] It includes transformer TF4 connected to the power amplifier, transformer TF2, and transformer TF3 connected to the other end of inductor L4;

[0020] Inductors, including inductor L1 with one end connected to transformer TF4, inductors L2 and L3 with one end connected to the other end of inductor L1, and inductor L4 with one end connected to the other end of inductor L2;

[0021] Capacitors, including capacitors C1, C3, and C4 connected in parallel, and capacitor C6 connected to the other end of inductor L3;

[0022] One end of the capacitors C1, C3, and C4 is connected to one end of inductor L1 and transformer TF4, and the other end is connected to the other end of inductor L2 and one end of inductor L4;

[0023] Resistors, including resistors R1, R2, R3, R4, resistors R7, R8, R9, and R10.

[0024] In a further embodiment, one end of the resistors R1 and R3, and the other end of the resistors R2 and R4 are connected to transformer TF3;

[0025] The other ends of the resistors R1 and R3 are connected to one end of the resistors R2 and R4;

[0026] One end of the resistor R9 is connected to one end of the resistor R7, one end of the resistor R8, and the transformer TF3, and the other end is connected to one end of the resistor R10 and the signal generator;

[0027] The other end of the resistor R7 is connected to the other end of the resistor R8;

[0028] A capacitor C5 is connected to one end of the resistor R9.

[0029] In a further embodiment, the other ends of the transformer TF4, the transformer TF2, the capacitor C6, the capacitor C5, the resistor R7, the resistor R8, and the resistor R10 are all grounded.

[0030] A method for matching the load of a particle accelerator electrode includes:

[0031] Step 1: Use a vacuum chamber to isolate the external circuit and the particle vacuum components;

[0032] The output of the matching sampling circuit passes through feedthrough a connector and enters the vacuum chamber, and is connected to the bunching electrode, which is located at the exact center of the beam transmission path;

[0033] Step 2: Use a signal generator to generate fundamental, second harmonic, and third harmonic signals, including controlling the amplitude and phase of the signals;

[0034] Step 3: Use a power amplifier to amplify the high-frequency signal to meet the reasonable electrode voltage requirements.

[0035] In a further embodiment, step 3 further includes:

[0036] Step 31: The matching sampling circuit is used to achieve impedance matching between the power amplifier and the bunching electrode, so that the power signal of the amplifier generates a sufficient bunching voltage on the bunching electrode;

[0037] Step 32: The matching sampling circuit is used to achieve real-time feedback sampling of the signal, send the sampling signal to the signal generator, dynamically realize the closed loop of feedback control, and the control software in the signal generator adjusts the amplitude and phase of the output signal according to the amplitude and phase information of the sampling signal obtained in real time, so as to meet the requirements of the sawtooth wave generation waveform for bunching.

[0038] The structure of the bunching electrode can be equivalent to a small capacitive load for high-frequency signals, and the capacitance is between dozens of pF. Usually, a particle accelerator requires a relatively high bunching voltage;

[0039] Generally, high-frequency signals need to be matched to work with a 50Ω load. At this time, the high-frequency signal output can be transmitted to the load. We can achieve the goal of a higher bunching voltage at a lower power through impedance transformation;

[0040] Taking into account the voltage requirements on the bunching electrode and the capacitive load characteristics of the bunching electrode, we designed a bunching matching and sampling circuit to couple the high-frequency signal power output to the bunching electrode while ensuring the generation of a high enough bunching voltage.

[0041] Beneficial effects: The present invention discloses a particle accelerator electrode load matching system and method. By designing a matching and sampling circuit, the present invention realizes impedance matching between the power amplifier and the bunching electrode, enabling the power signal of the power amplifier to generate a large enough bunching voltage on the bunching electrode. At the same time, the internal sampling circuit realizes real-time feedback sampling of the signal and sends this sampling signal to the signal generator to dynamically realize the closed-loop of feedback control;

[0042] The control software in the signal generator can adjust the amplitude and phase of the output signal according to the amplitude and phase information of the sampled signal obtained in real time to meet the requirements of the sawtooth wave generation waveform for bunching. Brief Description of the Drawings

[0043] Figure 1 is a schematic diagram of the system structure of the present invention.

[0044] Figure 2 is a schematic diagram of the matching and sampling circuit of the present invention.

[0045] Figure 3 is an ideal sawtooth wave waveform diagram of the present invention.

[0046] Figure 4 is a sawtooth wave diagram synthesized by the third harmonic of the present invention.

[0047] Figure 5 is a waveform diagram of each harmonic component of the third harmonic of the present invention.

[0048] Figure 6 is a time-domain waveform diagram after the synthesis of the third harmonic of the present invention.

[0049] Figure 7 is a reflection curve diagram of the present invention.

[0050] Figure 8 is a coupling feedback signal curve diagram of the present invention.

[0051] Figure 9 is a transmission phase curve diagram of different frequencies of the present invention. Detailed Embodiments

[0052] This application relates to a particle accelerator electrode load matching system and method, which will be explained in detail through specific embodiments below.

[0053] The ideal sawtooth wave contains rich harmonic components. In actual engineering design, many engineering factors need to be considered. At the same time, there should be a certain assessment metric for the distortion of the sawtooth wave, rather than the negative impact on the system indicators caused by the completely ideal sawtooth wave.

[0054] As shown in the attached Figure 3 Typically, we consider that the first 70% of the sawtooth wave is a linearly rising section, and the last 30% is a linearly falling section.

[0055] In practice, according to the Fourier series expansion, we know that the sawtooth wave is composed of the superposition of signals of multiple harmonics. From the perspective of the actual implementation of synthesizing the sawtooth signal and generating a higher voltage, the engineering implementation of the signal generator and power amplifier limits the implementation of the harmonic signal. From the perspective of controlling the signal bandwidth, the number of harmonic components should be minimized as much as possible. The contribution of higher-order harmonic components to the generation of the sawtooth waveform is relatively small.

[0056] Using the DC component and the first three harmonics to generate the signal as shown in the attached Figure 4 As shown (in engineering, we do not need the DC component), which includes the original curve and the restored curve.

[0057] The synthesis formula corresponding to the sawtooth wave is:

[0058] =

[0059] Where A represents the signal amplitude; f represents the signal frequency; t represents the time;

[0060] As shown in the attached Figure 5 and 6 As shown, it can be seen that the time-domain waveform after the synthesis of the third harmonic is approximately the shape of a sawtooth wave.

[0061] A particle accelerator electrode load matching system includes:

[0062] A signal generator for generating fundamental wave, second harmonic, and third harmonic signals, and simultaneously completing the control of the amplitude and phase of the signals;

[0063] A power amplifier connected to the signal generator for amplifying the signals;

[0064] A matching sampling circuit, connected to a power amplifier and a signal generator, is used to achieve impedance matching between the power amplifier and the bunching electrode, so that the power signal of the power amplifier generates a sufficiently large bunching voltage on the bunching electrode;

[0065] A vacuum chamber, connected to the matching sampling circuit;

[0066] A bunching electrode, arranged in the vacuum chamber and connected to the matching sampling circuit.

[0067] The sampling circuit inside the matching sampling circuit realizes real-time feedback sampling of the signal and sends the sampled signal to the signal generator, dynamically realizing the closed loop of feedback control. The control software in the signal generator adjusts the amplitude and phase of the output signal according to the amplitude and phase information of the sampled signal obtained in real time, so as to meet the requirements of the sawtooth wave generation waveform for bunching.

[0068] The matching sampling circuit includes:

[0069] Transformers, all of which are transmission transformers, are used to realize impedance ratio transformation and balance-unbalance conversion;

[0070] It includes transformer TF4 connected to the power amplifier, transformer TF2, and transformer TF3 connected to the other end of inductor L4;

[0071] Inductors, including inductor L1 with one end connected to transformer TF4, inductors L2 and L3 with one end connected to the other end of inductor L1, and inductor L4 with one end connected to the other end of inductor L2;

[0072] Capacitors, including capacitors C1, C3, and C4 connected in parallel, and capacitor C6 connected to the other end of inductor L3;

[0073] One ends of capacitors C1, C3, and C4 are connected to one end of inductor L1 and transformer TF4, and the other ends are connected to the other end of inductor L2 and one end of inductor L4;

[0074] Resistors, including resistors R1, R2, R3, R4, resistors R7, R8, R9, and R10;

[0075] One ends of resistors R1 and R3 and the other ends of resistors R2 and R4 are connected to transformer TF3;

[0076] The other ends of resistors R1 and R3 are connected to one ends of resistors R2 and R4;

[0077] One end of resistor R9 is connected to one ends of resistor R7, resistor R8, and transformer TF3, and the other end is connected to one end of resistor R10 and the signal generator;

[0078] The other end of the resistor R7 is connected to the other end of the resistor R8;

[0079] One end of the resistor R9 is connected with a capacitor C5;

[0080] The other ends of the transformer TF4, the transformer TF2, the capacitor C6, the capacitor C5, the resistor R7, the resistor R8, and the resistor R10 are all grounded.

[0081] A method for matching the load of a particle accelerator electrode, comprising:

[0082] Step 1: Use a vacuum chamber to isolate the external circuit and the particle vacuum components;

[0083] The output of the matching sampling circuit passes through feedthrough a connector and enters the vacuum chamber, and is connected to the bunching electrode, and the bunching electrode is located at the exact center position of the beam transmission path;

[0084] Step 2: Use a signal generator to generate fundamental, second harmonic, and third harmonic signals, including controlling the amplitude and phase of the signals;

[0085] Step 3: Use a power amplifier to amplify the high-frequency signal, so as to meet the reasonable electrode voltage requirements;

[0086] The said Step 3 further includes:

[0087] Step 31: The matching sampling circuit is used to achieve impedance matching between the power amplifier and the bunching electrode, so that the power signal of the amplifier generates a sufficiently large bunching voltage on the bunching electrode;

[0088] Step 32: The matching sampling circuit is used to achieve real-time feedback sampling of the signal, send the sampling signal to the signal generator, dynamically realize the closed loop of the feedback control, and the control software in the signal generator adjusts the amplitude and phase of the output signal according to the amplitude and phase information of the sampled signal obtained in real time, so as to meet the requirements of the sawtooth wave generation waveform for bunching.

[0089] For high-frequency signals, the bunching electrode structure can be equivalent to a small capacitive load, and the capacitance is between dozens of pF. Usually, a particle accelerator requires a relatively high bunching voltage;

[0090] Generally, high-frequency signals need to be matched to work under a 50Ω load. At this time, the high-frequency signal output can be transmitted to the load. We can achieve the goal of a higher bunching voltage at a lower power through impedance transformation;

[0091] Taking into account the voltage requirements on the bunching electrode and the capacitive load characteristics of the bunching electrode, we designed a bunching matching and sampling circuit to couple the high-frequency signal power output to the bunching electrode while ensuring that a sufficiently high bunching voltage is generated;

[0092] As shown in the Figure 2 attachment, the figure TermG shows the interface from the output of the power amplifier (power source) to the matching sampling circuit;

[0093] TermG2 represents the output of the sampling signal, which we can send to the signal generator to dynamically correct the amplitude and phase of the output signal;

[0094] C5 is the equivalent of the bunching electrode;

[0095] R1~R4 is the power absorption load, which realizes the improvement of power capacity in engineering through series and parallel methods;

[0096] The TF transformers are all transmission transformers used to realize impedance ratio transformation and balance-unbalance conversion;

[0097] This circuit can achieve the sawtooth wave matching output of the bunching electrode and broadband signal sampling in the frequency range of 20 MHz to 100 MHz.

[0098] As shown in the Figure 7 attachment, the designed reflection coefficient for the full frequency band is: the reflection coefficient is better than -24 dBc, which can meet the requirements of high-frequency power output matching.

[0099] As shown in the Figure 8 attachment, the coupled feedback signal is about -33.2 dBc in the full frequency band, and the flatness in the full frequency band is better than 0.2 dBc.

[0100] As shown in the Figure 9 attachment, the transmission phase curve is monotonically smooth, meeting the control requirements for the superposition of the phase relations of the third harmonics in the full frequency band.

[0101] Principle of operation: A vacuum chamber is used to isolate the external circuit from the particle vacuum components;

[0102] The output of the matching sampling circuit enters the vacuum chamber through the feedthrough connector and is connected to the bunching electrode, which is located at the exact center of the beam transmission path;

[0103] The generation of fundamental, second harmonic, and third harmonic signals is achieved through the signal generator, including the control of the amplitude and phase of the signals;

[0104] The power amplifier is used to amplify high-frequency signals, so as to meet the reasonable requirements for the electrode voltage.

[0105] The matching sampling circuit is used to achieve impedance matching between the power amplifier and the bunching electrode, so that the power signal of the amplifier generates a sufficiently large bunching voltage on the bunching electrode.

[0106] The matching sampling circuit is used to achieve real-time feedback sampling of the signal, send the sampling signal to the signal generator, and dynamically realize the closed loop of feedback control. The control software in the signal generator adjusts the amplitude and phase of the output signal according to the amplitude and phase information of the sampling signal obtained in real time, so as to meet the requirements for the waveform of the sawtooth wave generated for bunching.

[0107] The preferred specific embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above specific embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solution of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.

Claims

1. A particle accelerator electrode load matching system, It is characterized in that include: Signal generator, used to generate fundamental wave, second harmonic and third harmonic signals, and control signal amplitude and phase; A power amplifier, directly connected to the signal generator, for amplifying the signal; A matching sampling circuit is connected to the power amplifier and the signal generator, and is used to achieve impedance matching between the power amplifier and the bunching electrode, so that the power signal generates a bunching voltage on the bunching electrode. The matching sampling circuit includes a real-time feedback sampling unit, which dynamically feeds back the sampling signal to the signal generator to adjust the amplitude and phase of the output signal. a vacuum chamber in communication with a matching sampling circuit; The bunching electrode is arranged in the vacuum chamber and is located at the center of the beam transmission path.

2. A particle accelerator electrode load matching system according to claim 1, Its characteristics are: The matching sampling circuit comprises: Transformers, all of which are transmission transformers, are used to achieve impedance ratio transformation and balanced-unbalanced conversion; It includes a transformer TF4 and a transformer TF2 connected to the power amplifier, and a transformer TF3 connected to the other end of the inductor L4; Inductors, including an inductor L1 having one end connected to the transformer TF4, an inductor L2 having one end connected to the other end of the inductor L1, an inductor L3, and an inductor L4 having one end connected to the other end of the inductor L2; Capacitors, including capacitors C1, C3, and C4 connected in parallel, and a capacitor C6 connected to the other end of the inductor L3; One end of the capacitor C1, the capacitor C3, and the capacitor C4 is connected to one end of the inductor L1 and the transformer TF4, and the other end is connected to the other end of the inductor L2 and one end of the inductor L4; The resistors include a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R7, a resistor R8, a resistor R9, and a resistor R10.

3. A particle accelerator electrode load matching system according to claim 1, Its characteristics are: One end of the resistor R1 and the resistor R3, and the other end of the resistor R2 and the resistor R4 are connected to the transformer TF3; The other ends of the resistors R1 and R3 are connected to one ends of the resistors R2 and R4; One end of the resistor R9 is connected to one end of the resistor R7, one end of the resistor R8, and the transformer TF3, and the other end is connected to one end of the resistor R10 and the signal generator; The other end of the resistor R7 is connected to the other end of the resistor R8; One end of the resistor R9 is connected to a capacitor C5.

4. A particle accelerator electrode load matching system according to claim 3, Its characteristics are: The transformer TF4, the transformer TF2, the other end of the capacitor C6, the other end of the capacitor C5, the other end of the resistor R7, the resistor R8, and the other end of the resistor R10 are all grounded.

5. A particle accelerator electrode load matching method, It is characterized in that include: Step 1: Use a vacuum chamber to isolate the external circuit and the particle vacuum components; The output of the matched sampling circuit is feedthrough The connector enters the vacuum chamber and is connected to the bunching electrode, which is located in the exact center of the beam transmission path; Step 2: Using a signal generator, the fundamental wave, second harmonic, and third harmonic signals are generated, including the control of the amplitude and phase of the signal; Step 3: Use a power amplifier to amplify the high-frequency signal to meet reasonable electrode voltage requirements.

6. A particle accelerator electrode load matching method according to claim 5, Its characteristics are: The step 3 also includes: Step 31, making the power signal of the amplifier generate a sufficiently large focusing voltage on the focusing electrode; Step 32, the sampling signal is sent to the signal generator to dynamically realize the closed loop of feedback control. The control software in the signal generator adjusts the amplitude and phase of the output signal according to the amplitude and phase information of the sampling signal obtained in real time, thereby meeting the waveform requirements of the sawtooth wave for beam focusing.

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