The Control System Of The ECR-IS And LEBT,vacuum And Cryo-module Used In ADS Injector â…¡

Accelerator driven sub-critical(ADS) system can not only reduce dramatically nuclear waste, but also generate advanced power. It has been recognized in the world as one of the most effective tool for the transmutation of the long-lived nuclear waste. It consists of an accelerator, a spallation target and a sub-critical reactor. The high-energy proton beam generated by the accelerator bombards the target to generate spallation neutrons. Then, the intense spallation neutrons are used as external neutrons to drive the sub-critical reactor. Under the frame of “Strategic Priority Research Program”, the Chinese Academy of Sciences initiated an ADS program to build an ADS test system in 2011. In China ADS system, the proton accelerator includes two injectors, and the injector Ⅱ is undertaken by Institute of Modern Physics(IMP). As a high current linac, the injector Ⅱ consists of an electron cyclotron resonance ion source(ECR-IS), a radio frequency quadrupole(RFQ), superconducting section and several related beam lines.The performance of the injector Ⅱ, especially the stability and reliability of the control system, will have a significant impact on ADS. According to the trend of the advanced accelerator control system in the world, the distributed control system at IMP is based on Experimental and Physics Industrial Control System(EPICS) framework and high-speed Ethernet. It has the advantages of high reliability, fast response, openness and scalability to meet the requirements of high current linac.In this thesis, several sub-systems in injector Ⅱ are introduced in detail, including ECR-IS, Low Energy Beam Transport(LEBT), vacuum system, cryogenic valve-box and cryo-module. The remote control of devices has been implemented in the control system, which provides convenient operation and reduces the maintenance workload. In addition, the function of interlock which based on programmable logic controllers(PLCs) has been developed. The system will take necessary protective measures when the controlled equipment fails to protect the staff and equipment from damage.The control system architecture, hardware and software design are discussed in detail, and the implementation of the control system is given for the high reliability requirements of ADS accelerator. In the aspect of hardware, the general control modules are used widely and the corresponding distributed control system is built to ensure the performance of the control system. The control software is designed under the frame of the EPICS, and the automatic reconnection technology is applied in the program to improve the fault-tolerant performance. Thus the designed control system can operate reliably for a long time. The Input Output Controller(IOC) interface program has been programmed with Lab VIEW. The program data has been integrated successfully into the EPICS framework by using the Data-logging and Supervisory Control(DSC) module. This integration ensures the transparency and integrity of the ADS control data.There are several special innovations in the thesis. Firstly, the intake valve of H2 in ECR-IS is controlled by servo motor accurately, and the open ratio can be accurate to 0.01 degree. Secondly, the ECR-IS control system is designed to avoid being affected by the discharge of high voltage equipment. Finally, the operating pressure of the cryo-module is achieved closed-loop control by incremental digital PID algorithm. The pressure fluctuation is less than 100 Pa, the general requirement is 150 Pa, to provide a stable operating condition for the superconducting cavity.The above-mentioned sub-systems have been designed and implemented completely. In the successful commissioning of proton beam with the energy of 5.1 Me V and 2.7 m A in injector Ⅱ in June 2015, the developed control sub-systems have played an important role.