Design and development of the CSNS ion source control system

Now that the CSNS ion source test stand has been stably working for years, an online control system for the CSNS ion source which aims to be more stable and reliable is now under development. F3RP61-2L, a new PLC CPU module running an embedded Linux system, is introduced to the system as an IOC, to function together with the I/O modules of FA-M3 PLC on the PLC-bus. The adoption of the new IOC not only simplifies the architecture of the control system, but also improves the data transmission speed. In this paper, the design and development of the supervisory and control system for the CSNS ion source are described.     

Control system for the CSNS ion source test stand

A penning plasma surface H- ion source test stand for the CSNS has just been constructed at the IHEP. In order to achieve a safe and reliable system, nearly all devices of the ion source are designed to have the capability of both local and remote operation function. The control system consists of PLCs and EPICS real-time software tools separately serving device control and monitoring, PLC integration and OPI support. This paper summarizes the hardware and software implementation satisfying the requirements of the ion source control system.     

Status of CSNS H- ion source

A new H^- ion source has been installed successfully and will be used to serve the China Spallation Neutron Source (CSNS). In this paper, we report various components of the ion source, including the discharge chamber, temperature, cooling system, extraction electrodes, analyzing magnet, remote control system and so on. Compared to the previous experimental ion source, some improvements have been made to make the ion source more compact and convenient. In the present arrangement, the Penning field is generated by a pair of pole tip extensions on the 90° analyzing magnet instead of by a separate circuit. For the remote control system, F3RP61-2L is applied to the accelerator online control system for the first time. In the running of the ion source, a stable pulse H^- beam with a current of 50 mA at an energy of 50 keV is produced. The extraction frequency and pulse width is 25 Hz and 500 μs, respectively. Furthermore, an emittance scanner has been installed and measurements are in progress.     

基于BEPCⅡ数据的数字束流位置测量器算法离线分析

介绍了数字BPM算法的原理和架构，并基于高能物理研究所自制的数字BPM硬件平台获取了BEPC Ⅱ束流流强为600 mA条件下的ADC采样数据。然后在MATLAB环境中设计了NCO模块、CIC滤波器、FIR滤波器以及BEPC Ⅱ束流逐圈位置数据计算模块，并给出了各模块的具体设计参数。最后通过实际ADC数据对各算法模块进行检验，给出了各模块处理后的频域分析结果，并得到了实际束流下水平方向和垂直方向上的逐圈位置分辨率分别为4.55 μm和4.28 μm，为FPGA在线算法的实现与优化提供了可靠的理论依据。     

CSNS H^- ion source test stand

The Penning surface plasma source is adopted as the China Spallation Neutron Source (CSNS) H^- ion source. The designed energy and beam current of the source are 50 keV and 20 mA, respectively, with a normalized root mean square (norm. rms.) emittance of 0.2 πmm·mrad. The construction of a H^- ion source test stand has been completed, and the commissioning of the source is in progress. Stable H^- ion beams with energy of 50 keV and current up to 50 mA are attained. Emittance measurement for the H^- beam is being prepared.