Research And Design Of Control System For Electron Cooler And Electron Target In HIAF

The electron cooler and electron target are significant components of next generation high-intensity ion facility HIAF（High-Intensity heavy ion Accelerator Facility）,both of them are located in the spectrometer ring.The main principle of the electron target is similar to that of electron cooler,but it requires higher control precision and energy detuning performance.The dissertation mainly researches the control system about the electron cooler and electron target.According to the requirements of the HIAF,the control system has been independently designed and completely self-developed.The ordinary high voltage power supply cannot meet the beam requirements with the increase of the electron beam energy.It is necessary through the cascade transformer in series with high-voltage modules to generate high-power,low-ripple and high voltage electric field which is up to 600k V.Traditional control and communication methods cannot meet such complex control requirements.Therefore,a special embedded controller needed to be designed at the bottom layer.In terms of hardware research and development,this dissertation designs a high-voltage controller that can directly perform physical calculations,which can be applied to electron cooler or electron target devices by adjusting the internal program and firmware,and can also be extended to other devices according to requirements.The controller solves the deficiencies of current controllers.It mainly includes the inability to synchronize with the synchronization ring,the slow acquisition of data,the use of the antenna in high voltage to cause tip discharge,the inability to dynamically adjust the energy according to the experiment,and to remotely diagnose faults.Inside the controller,a soft processor for experimental waveform calculation is implemented through FPGA.In electron target scenario,the processor could output the waveforms in real time per cycle to dynamically adjust the electron beam state based on the experimental parameters.About software,all control logics are integrated in the controller.the EPICS Framework is embedded in the operating system,so that the outside can control directly through the Channel Access protocol without additional protocol analysis.The high-voltage platform communication of the entire electron cooler control system is based on the XGS-PON（10-Gigabit-capable symmetric PON）network design.It enters the sealed high-pressure tank through an optical fiber,and then communicates with each controller through the optical splitter.The speed of a single node can reach 550MB/s.The communication of the electron target control system is based on optical fiber synchronous triggering and Gigabit optical fiber Ethernet.The bottom controller acts according to predetermined parameters,more than ten times of electron beam energy detuning experiments can be realized per injection cycle,which is more efficient than the existing system.Non-embedded devices introduce containerization and automatic scheduling IOC design.Through this design,it solves the problem that the overall availability of the control system decreases as the scale increases,make it possible that the availability of large-scale control systems increases as the scale increases.Through the research and design,the new control system has been tested and experimented on the CSRm.Its key performance has been greatly improved.The adjustment accuracy of the high-voltage platform is 0.1V;the minimum time adjustment step is 10ns;the full-scale automatic spectrum sweep time is less than 4hours and the core temperature of the prototype is less than 50 degrees Celsius for long-term beam supply operation.Through the analysis of Ar¹⁵⁺experimental data,the new control system can quickly scan and obtain the complete DR spectrum within the range,which is consistent with the key spectrum peaks calculated by theoretical calculation.At the same time,for the tiny energy peaks that cannot be calculated theoretically,the new control system also achieves better resolution than the original system;after the system sets finer local scanning parameters,the detailed values of the spectrum can be obtained.The test and experimental results show that the new control system successfully replaces the original electron cooler control system which is built by Russian in HIRFL and improves and expands its performance.The design meets the design requirements of HIAF electron cooler and electron target.