A method and device for detecting and self-recovering of accelerator sparking

Abstract

This invention relates to a method for arc detection and self-recovery in an accelerator. The accelerator includes a digital radio frequency low-level system, a power source, and a radio frequency resonant cavity. The method includes: acquiring the cavity pressure signal of the radio frequency resonant cavity using the digital radio frequency low-level system, and detecting whether an arc event has occurred based on the cavity pressure signal; when an arc event is detected, the digital radio frequency low-level system switches the current normal output signal to the power source to an automatic recovery signal for automatic recovery; after automatic recovery is completed, the digital radio frequency low-level system switches the output back to the current normal output signal to the power source. This solution can be applied to the digital radio frequency low-level system of an accelerator to realize arc detection and fault recovery, reducing the fault recovery time to the millisecond level, and improving the accelerator's operating efficiency and availability.

Description

Technical Field

[0001] This invention relates to the field of particle accelerator technology, and in particular to a method and apparatus for detecting and self-recovering arcing in an accelerator. Background Technology

[0002] An accelerator is a device that artificially accelerates charged particles to higher energies. Such devices can produce electrons, protons, deuterons, alpha particles, and other heavy ions at various energies. A crucial component of an accelerator is the radio frequency cavity system, taking the radio frequency quadrupole (RFQ) accelerator as an example. The RFQ utilizes four modulated electrodes to simultaneously generate longitudinal acceleration and lateral focusing components, integrating particle acceleration, longitudinal clustering, and lateral matching functions into a single structure, thus offering advantages such as compact design and comprehensive functionality. Currently, the RFQ scheme is widely used in various high-power particle accelerators.

[0003] However, the inventors of this application discovered in their research that arcing faults caused by field emission effects are a common problem faced by accelerator systems during operation. Existing technologies, after determining that an arcing fault has occurred, require cutting off radio frequency power, shutting down the accelerator resonant cavity, and waiting for the fault to recover before reloading. This entire process takes tens of minutes, significantly reducing the accelerator's efficiency and availability. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide an accelerator arc detection and self-recovery method and apparatus that can be applied to the digital low-level radio frequency (LLRF) system of the accelerator, realize arc detection and fault recovery of the accelerator, reduce the fault recovery time to the millisecond level, and improve the working efficiency and availability of the accelerator.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, this application provides a spark detection and self-recovery method for an accelerator, applied to an accelerator including a digital radio frequency low-level system, a power source, and a radio frequency resonant cavity, the method comprising:

[0007] The cavity pressure signal of the radio frequency resonant cavity is obtained using the digital radio frequency low-level system, and the occurrence of an arcing event is detected based on the cavity pressure signal.

[0008] When an arcing event is detected, the digital radio frequency low-level system switches the current normal output signal to the power source to an automatic recovery signal for automatic recovery. The amplitude of the automatic recovery signal is lower than the amplitude of the current normal output signal to the power source.

[0009] After automatic recovery is complete, the digital radio frequency low-level system will switch its output to the normal output signal currently being sent to the power source.

[0010] In one implementation of this application, obtaining the cavity pressure signal of the radio frequency resonant cavity using the digital radio frequency low-level system includes:

[0011] An extraction antenna is set in the radio frequency resonant cavity, and the digital radio frequency low-level system is connected to the extraction antenna to obtain the I / Q sequence of the IQ sampling of the radio frequency resonant cavity.

[0012] In one implementation of this application, the step of detecting whether an arcing event has occurred based on the cavity pressure signal includes:

[0013] The amplitude of the cavity pressure signal is obtained by rotating the acquired I / Q (In-phase / Quadrature phase) sequence using CORDIC (Coordinate Rotation Digital Computer).

[0014] The amplitude of the cavity pressure signal is buffered in a FIFO (First in, First out) and subtracted from the current value of the amplitude. The absolute value is then taken to obtain the change in amplitude.

[0015] The change in amplitude is compared with a set threshold. If the change is greater than the threshold, an ignition event is detected.

[0016] In one implementation of this application, the threshold is set by the host computer of the digital radio frequency low-level system.

[0017] In one implementation of this application, when an arcing event is detected, the digital radio frequency low-level system switches the current normal output signal to the power source to an automatic recovery signal, including:

[0018] When an arcing event is detected, the digital radio frequency low-level system generates a trigger signal and outputs an automatic recovery signal to the power source on the falling edge of the trigger signal.

[0019] In one implementation of this application, the step of outputting an automatic recovery signal to the power source includes:

[0020] The falling edge of the trigger signal triggers the counter to operate, causing the counter to count a set duration. Within the set duration, a safety value signal is output to the power source, and the amplitude of the safety value signal is lower than the amplitude of the current normal output signal to the power source.

[0021] In one implementation of this application, the step of outputting an automatic recovery signal to the power source further includes:

[0022] The amplitude of the safety value signal is continuously accumulated according to a set step size until the amplitude of the output signal reaches the set low-level control signal amplitude.

[0023] In one implementation of this application, the amplitude of the safety value signal, the step size, and the amplitude of the low-level control signal are set by the host computer of the digital radio frequency low-level system.

[0024] Secondly, this application also provides an arc detection and self-recovery device for an accelerator, applied in the digital radio frequency low-level system of the accelerator, wherein the accelerator further includes a power source and a radio frequency resonant cavity, and the device includes:

[0025] The Arc detection module is used to acquire the cavity pressure signal of the RFQ resonant cavity and detect whether an arcing event has occurred based on the cavity pressure signal.

[0026] An automatic recovery module is used to switch the current normal output signal to the power source to an automatic recovery signal when an arcing event is detected, performing automatic recovery. The amplitude of the automatic recovery signal is lower than the amplitude of the current normal output signal to the power source.

[0027] The normal output module is used to switch the output to the normal output signal to the power source after automatic recovery is completed.

[0028] In one implementation of this application, the normal output module is configured by the host computer of the digital radio frequency low-level system to output an arbitrary waveform signal;

[0029] The digital radio frequency low-level system specifically includes an FPGA (Field Programmable Gate Array); the power source is a solid-state power source; and the radio frequency resonant cavity includes an RFQ room-temperature cavity.

[0030] The present invention has the following advantages due to the adoption of the above technical solutions: In the solution of the present invention, the cavity pressure signal of the radio frequency resonant cavity is obtained by a digital radio frequency low-level system, and the detection of whether an arcing event has occurred is performed based on the cavity pressure signal. When an arcing event is detected, the digital radio frequency low-level system switches the current normal output signal to the power source to an automatic recovery signal. After the automatic recovery is completed, the digital radio frequency low-level system switches the output back to the current normal output signal to the power source. Thus, the solution can be implemented in the digital radio frequency low-level system of the particle accelerator platform without the need for additional hardware equipment, and the detection and recovery time is compressed to within 1ms, thereby improving the working efficiency and availability of the accelerator. Attached Figure Description

[0031] Figure 1 This is a structural block diagram of an accelerator arc detection and self-recovery device provided in an embodiment of this application;

[0032] Figure 2 This is a schematic diagram of the algorithm flow for an accelerator arc detection and self-recovery method provided in an embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the signal principle for ignition determination and self-recovery in the embodiments of this application. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0035] To address the technical problem of low accelerator efficiency caused by the existing technology requiring tens of minutes of operation—including cutting off RF power, shutting down the accelerator resonant cavity, and waiting for the fault to recover—after determining that an accelerator has experienced an arcing fault, this application provides an accelerator arcing detection and self-recovery method and apparatus. The method includes: acquiring the cavity pressure signal of the RF resonant cavity using a digital RF low-level system, and detecting whether an arcing event has occurred based on the cavity pressure signal; when an arcing event is detected, the digital RF low-level system switches the current normal output signal to the power source to an automatic recovery signal for automatic recovery, wherein the amplitude of the automatic recovery signal is lower than the amplitude of the current normal output signal to the power source; after automatic recovery is completed, the digital RF low-level system switches the output back to the current normal output signal to the power source. This solution can be applied to the digital RF low-level system of an accelerator to achieve arcing detection and fault recovery, reducing the fault recovery time to the millisecond level, and improving the accelerator's efficiency and availability.

[0036] See Figure 1 In one embodiment of this application, a schematic diagram of the architecture of an accelerator arc detection and self-recovery device is provided.

[0037] Specifically, in this embodiment, the accelerator includes a digital radio frequency low-level system, a power source, and a radio frequency resonant cavity. The core components of the digital radio frequency low-level system can be, but are not limited to, implemented using an FPGA, such as the ZYNQ7100 FPGA chip. The power source is a solid-state power source, each containing 24 inserts (model: KFPA-162-1-1), with a saturated output power of approximately 1.4kW for a single insert.

[0038] In the embodiments of this application, the radio frequency resonant cavity has various implementation schemes, such as a room temperature cavity, including an RFQ and a beamformer, and the radio frequency resonant cavity can also be a superconducting cavity. In the embodiments of this application, an RFQ resonant cavity will be used as an example.

[0039] Please see Figure 1As with conventional techniques, the FPGA in a digital radio frequency low-level system includes a normal output module and an output module. The normal output module can be an arbitrary waveform generator, capable of producing arbitrary waveform signals according to the actual needs of particle experiments or radiotherapy, such as, but not limited to, sine waves, half-sine waves, sawtooth waves, etc. The output module is used to switch between the normal output mode and the abnormal handling (i.e., arc detection and automatic recovery) output mode of the normal output module. It's easy to understand that when no arcing occurs, the output module outputs the signal from the normal output module to a power source, which amplifies the signal to generate a power signal that is delivered to the RFQ resonant cavity. This power signal then generates a radio frequency signal in the RFQ resonant cavity to accelerate or decelerate the particles.

[0040] In existing technologies, arcing faults caused by field emission effects are a common problem faced by RFQ accelerators during operation. To address this issue, this application designs a scheme for arcing detection and self-recovery in a digital RF low-level system.

[0041] The spark detection and self-recovery device in this application includes:

[0042] The Arc (electric arc, also known as sparking) detection module is used to acquire the cavity pressure signal of the radio frequency resonant cavity and detect whether a sparking event has occurred based on the cavity pressure signal.

[0043] An automatic recovery module is used to switch the current normal output signal to the power source to an automatic recovery signal when an arcing event is detected, performing automatic recovery. The amplitude of the automatic recovery signal is lower than the amplitude of the current normal output signal to the power source.

[0044] The normal output module is used to switch the output to the normal output signal to the power source after automatic recovery is completed.

[0045] The device of this application uses a digital radio frequency low-level system to acquire the cavity pressure signal of the radio frequency resonant cavity and detects whether an arcing event has occurred based on the cavity pressure signal. When an arcing event is detected, the digital radio frequency low-level system switches the current normal output signal to the power source to an automatic recovery signal. After the automatic recovery is completed, the digital radio frequency low-level system switches the output back to the current normal output signal to the power source. This allows the solution to be implemented in the digital radio frequency low-level system of the particle accelerator platform without the need for additional hardware devices, while compressing the detection and recovery time to within 1ms, thereby improving the working efficiency and availability of the accelerator.

[0046] The following is combined Figure 1 , Figure 2 and Figure 3This explains the principle and advantages of the accelerator's arc detection and self-recovery method in the embodiments of this application.

[0047] In this embodiment of the application, the accelerator's spark detection and self-recovery method is applied to Figure 1 The device in the middle. The method specifically includes:

[0048] The cavity pressure signal of the RFQ resonant cavity is obtained using the digital radio frequency low-level system, and the occurrence of an arcing event is detected based on the cavity pressure signal.

[0049] When an arcing event is detected, the digital radio frequency low-level system switches the current normal output signal to the power source to an automatic recovery signal, the amplitude of which is lower than the amplitude of the current normal output signal to the power source.

[0050] After automatic recovery is complete, the digital radio frequency low-level system will switch its output to the normal output signal currently being sent to the power source.

[0051] Please see Figure 2 and Figure 3 The specific algorithm principles include:

[0052] (1) An extraction antenna is set in the RFQ resonant cavity and connected to the extraction antenna through the digital radio frequency low level system to obtain the I / Q sequence of the IQ sampling of the RFQ resonant cavity.

[0053] (2) The amplitude of the cavity pressure signal is obtained by CORDIC rotation based on the acquired I / Q sequence;

[0054] The amplitude of the cavity pressure signal is buffered in a FIFO (for example, to achieve a 5-microsecond delay), and then subtracted from the current value of the amplitude. The absolute value is then taken to obtain the change in amplitude.

[0055] The change in amplitude is compared with a set threshold. If the change is greater than the threshold, an ignition event is detected.

[0056] In one embodiment of this application, the threshold is set by the host computer of the digital radio frequency low-level system.

[0057] (3) When an arcing event is detected, the digital radio frequency low-level system generates a trigger signal and outputs an automatic recovery signal to the power source on the falling edge of the trigger signal.

[0058] More specifically, the counter is triggered to operate on the falling edge of the trigger signal, so that the counter counts for a set duration (e.g., 100 microseconds), and outputs a safety value signal to the power source within the set duration. The amplitude of the safety value signal is 70% smaller than the amplitude of the current normal output signal to the power source.

[0059] After the counter reaches the set time, the amplitude of the safety value signal is continuously accumulated according to the set step size until the amplitude of the output signal reaches the set low-level control signal amplitude.

[0060] In one embodiment of this application, the amplitude of the safety value signal, the step size, and the amplitude of the low-level control signal are set by the host computer of the digital radio frequency low-level system.

[0061] (4) Switch to the previous normal output.

[0062] In summary, by adopting the above technical solutions, the embodiments of this application can build an Arc detection and Arc self-recovery module inside the FPGA to achieve millisecond-level self-recovery after the RFQ accelerator is ignited and to run stably, thereby improving the accelerator's operating efficiency. At the same time, it can be deployed inside a low-level system without the need to add additional hardware devices.

[0063] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0064] In the embodiments provided by this invention, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units through some interfaces, and may be electrical, mechanical, or other forms.

[0065] The integrated units implemented as software functional units described above can be stored in a computer-readable storage medium. These software functional units, stored in a storage medium, include several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute some steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for arc detection and self-recovery in an accelerator, applied to an accelerator, the accelerator comprising a digital radio frequency low-level system, a power source, and a radio frequency resonant cavity, characterized in that, The method includes: The cavity pressure signal of the radio frequency resonant cavity is obtained using the digital radio frequency low-level system, and the occurrence of an arcing event is detected based on the cavity pressure signal. When an arcing event is detected, the digital radio frequency low-level system switches the current normal output signal to the power source to an automatic recovery signal for automatic recovery. The amplitude of the automatic recovery signal is lower than the amplitude of the current normal output signal to the power source. After automatic recovery is complete, the digital radio frequency low-level system will switch its output to the normal output signal currently being sent to the power source.

2. The accelerator arc detection and self-recovery method according to claim 1, characterized in that, The step of acquiring the cavity pressure signal of the radio frequency resonant cavity using the digital radio frequency low-level system includes: An extraction antenna is set in the radio frequency resonant cavity, and the digital radio frequency low-level system is connected to the extraction antenna to obtain the I / Q sequence of the IQ sampling of the radio frequency resonant cavity.

3. The accelerator arc detection and self-recovery method according to claim 2, characterized in that, The detection of whether an arcing event has occurred based on the cavity pressure signal includes: The amplitude of the cavity pressure signal is obtained by CORDIC rotation based on the acquired I / Q sequence. The amplitude of the cavity pressure signal is buffered in a FIFO, and then subtracted from the current value of the amplitude. The absolute value is then taken to obtain the change in amplitude. The change in amplitude is compared with a set threshold. If the change is greater than the threshold, an ignition event is detected.

4. The accelerator arc detection and self-recovery method according to claim 3, characterized in that, The threshold is set by the host computer of the digital radio frequency low-level system.

5. The accelerator arc detection and self-recovery method according to claim 3, characterized in that, When an arcing event is detected, the digital radio frequency low-level system switches the current normal output signal to the power source to an automatic recovery signal, including: When an arcing event is detected, the digital radio frequency low-level system generates a trigger signal and outputs an automatic recovery signal to the power source on the falling edge of the trigger signal.

6. The accelerator arc detection and self-recovery method according to claim 5, characterized in that, The step of outputting an automatic recovery signal to the power source includes: The falling edge of the trigger signal triggers the counter to operate, causing the counter to count a set duration. Within the set duration, a safety value signal is output to the power source, and the amplitude of the safety value signal is lower than the amplitude of the current normal output signal to the power source.

7. The accelerator arc detection and self-recovery method according to claim 6, characterized in that, The step of outputting an automatic recovery signal to the power source further includes: The amplitude of the safety value signal is continuously accumulated according to a set step size until the amplitude of the output signal reaches the set low-level control signal amplitude.

8. The accelerator arc detection and self-recovery method according to claim 7, characterized in that, The amplitude of the safety value signal, the step size, and the amplitude of the low-level control signal are set by the host computer of the digital radio frequency low-level system.

9. An arc detection and self-recovery device for an accelerator, applied in the digital radio frequency low-level system of the accelerator, wherein the accelerator further includes a power source and a radio frequency resonant cavity, characterized in that, The device includes: The Arc detection module is used to acquire the cavity pressure signal of the radio frequency resonant cavity and detect whether an arcing event has occurred based on the cavity pressure signal. An automatic recovery module is used to switch the current normal output signal to the power source to an automatic recovery signal when an arcing event is detected, performing automatic recovery. The amplitude of the automatic recovery signal is lower than the amplitude of the current normal output signal to the power source. The normal output module is used to switch the output to the normal output signal to the power source after automatic recovery is completed.

10. The accelerator spark detection and self-recovery device according to claim 9, characterized in that, The normal output module is set by the host computer of the digital radio frequency low-level system to output arbitrary waveform signals. The digital radio frequency low-level system specifically includes an FPGA; the power source is a solid-state power source; and the radio frequency resonant cavity includes an RFQ room-temperature cavity.

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