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中国散裂中子源(China Spallation Neutron Source, CSNS)是国家“十一五”期间重点建设的大科学装置[1]。CSNS一期由1台80 MeV的负氢直线加速器、1台1.6 GeV的快循环质子同步加速器、两条束流输运线、1个靶站和3台谱仪及相应的配套设施组成[2]。
CSNS直线加速器(Linear accelerator,Linac)一期工作在频率324 MHz、脉宽650 μs、重复频率25 Hz的射频的脉冲功率下[3-4]。直线加速器包含8套加速器单元,主要有1套RFQ(Radio-Frequency Quadrupole)、4套DTL(Drift Tube Linac)、2套聚束器和1套散束器。每套加速器单元都配备一套低电平射频控制系统。低电平射频控制系统主要完成以下几个功能:幅度相位控制、射频保护、加速器腔体频率控制、数据存储以及远程控制等。CSNS直线加速器低电平控制系统(Low Level Radio Frequency Control System,LLRF)一期主要运行指标如表1所列。
项目 指标 项目 指标 腔场幅度稳定度 ≤±1% 腔场相位稳定度 ≤±1° RF输出信号形式 脉冲 重复频率 25 pps RF脉冲宽度 650 μs 输出RF信号频率 324 MHz 采样时钟频率 144 MHz 中频频率 36 MHz LLRF闭环反应时间 <1 μs
Design of Low Level Radio Frequency Control Software for CSNS LINAC
doi: 10.11804/NuclPhysRev.39.2021049
- Received Date: 2021-06-03
- Rev Recd Date: 2021-07-15
- Publish Date: 2022-03-01
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Key words:
- linear accelerator /
- accelerator cavity /
- feedforward /
- tuner /
- RF power source /
- automatic
Abstract: The low-level radio frequency control system(LLRF) is mainly used to control the electric field and resonate frequency of the accelerating cavity to ensure the stable operation of the accelerator and output high-quality beam. The LLRF software provides a graphical user interface, and realize the functions such as data display and storage, as well as some algorithm like automatic logic and so on. A well-designed LLRF software improves the operability of the LLRF and reduces the amount of manual work and failure rate. This paper introduces the development and design of LLRF software for China spallation neutron source(CSNS) linac, mainly including feedforward automatic calculation, automatic frequency control of acceleration cavity, frequency detuning algorithm, automatic RF power up and so on. Finally, the amplitude and phase stability index of the system is better than the required design index, and meets the requirements of long-term stable operation.
Citation: | Zhexin XIE, Zhencheng MU, Jian LI, Linyan RONG, Song LI, Wenzhong ZHOU, Ahong LI, Xiaolei WU, Yongchuan XIAO, Yuliang ZHANG, Bo WANG, Maliang WAN, Meifei LIU, Hui ZHANG, Xin'an XU. Design of Low Level Radio Frequency Control Software for CSNS LINAC[J]. Nuclear Physics Review, 2022, 39(1): 45-53. doi: 10.11804/NuclPhysRev.39.2021049 |