The High Power and Low Level RF Group is mainly focused on the development and engineering application of the generation of RF energy for superconducting linear accelerators and the precise control technology for the acceleration of particles.
The High Power RF technology is led by the advance of high intensity linear accelerator projects, and carries out related technology research on the high power solid-state RF power sources, which mainly includes high frequency and high power generation, combination, transmission and measurement. It focuses on the development status of the mainstream semiconductor power devices and the high efficient RF power amplifiers, and also promotes the urgent needs to be solved, such as high efficiency and high isolation RF power amplifiers and combiners, high precision RF power measurement under extreme load conditions, and reliability improvement of high power RF systems. The low level RF control system is used to keep the stability and safety of beam operation in particle accelerator, which is necessary to precisely control the RF electromagnetic field in the superconducting cavity, and reduce the noise interference on the beam quality. It mainly includes the real time monitoring and high precision measurement of the electromagnetic field in the superconducting cavity, using high speed RF feedback control technology to adjust the output of the high power solid-state RF power source, in order to achieve the stable control of electromagnetic field in the superconducting cavity.
The High Power and Low Level RF Group is mainly responsible for the construction and commissioning of RF power source and Low Level RF control system for superconducting accelerators in CiADS, HIAF and other projects, and also responsible for the maintenance and upgrade tasks of the RF power and Low Level RF systems in the projects of CAFe, LEAF and other operating facilities. At present, the RF power source mainly uses solid-state power amplification technology based on LDMOS devices, and further obtains higher RF power through coaxial RF power combination. The low level RF control system uses FPGA-based full digital control technology, VXI backplane bus technology and new PXIe industrial measurement and control bus technology, and uses high-speed digital signal processing technology based on DSP and FPGA to develop and deploy real-time radio frequency feedback control algorithms to achieve stable and reliable control of RF electromagnetic fields in superconducting cavities.
1. High power RF technology
Research on the generation, transmission, match, distribution, combination and measurement of RF power;
Reliability study on high power RF equipment;
Research on the interaction between high power RF system and narrow band resonant system;
Intelligent parameter monitor and analysis of high power RF sources.
2. LLRF control technology
High precision electronic measurement technology for radio frequency signals;
High precision RF reference distribution technology;
High speed digital signal processing technology;
Research on machine learning algorithms for LLRF control system;
Research on modern control theory;
System identification technology.
3. Research on stability of superconducting RF system
System design, risk assessment, parameter optimization of RF system;
Research on the interaction between beam, superconducting cavity and RF power source;
Research on the reliability and stability of superconducting RF systems.
1. Completed the development of more than 30 sets of solid state RF power sources for ADS 25 MeV superconducting linear accelerators, the total RF power is more than 400 kW, and achieved the long term operation of large scale solid state RF power sources with continuous wave high power and total reflection for the first time in China;
2. The low level RF control system of ADS pilot project uses FPGA-based all digital control technology, VXI backplane bus technology and the new PXIe industrial measurement and control bus technology to achieve stable and reliable control of high power superconducting accelerators, it guaranteed the smooth acceptance test and long-term stable operation of high power continuous beam of ADS pilot project;
3. Members of the group have published more than 10 papers in core journals of SCI and Chinese in recent years. The research results of solid state RF power sources and low level RF control systems for superconducting accelerators have promoted technological innovation in the domestic high power solid state RF power source industry.