The Design And Implementation Of Front-end Control System Of Beam Diagnostics For HIMM

This paper takes the beam diagnostics front-end controls system of heavy ion medical machine(HIMM) as the research object. The standard control system architecture with 3 layers is designed, and the modularity software framework is implemented based on the selected hardware. Some of the applications developed with the developed software and hardware architecture were tested with beam at the radioactive ion beam line at Lanzhou 2(RIBLL2) and cyclotron of HIMM.On basis of the beam diagnostics detectors and the characteristics of its front-end electronics output signal, the design principal of the beam diagnostics control system is analyzed. Meanwhile, the hardware plateform is determinded. The hardware of beam diagnostics front-end control system for HIMM is based on FPGA and real-time operating system, compared with that for the present beam diagnostics control system of HIRFL which is based on serial port and single chip microcomputer. The application of FPGA can fulfill the requirements of the precise timing, trigger, control, synchronization and user-defined high speed communication protocol requirements. The real-time operating system can ensure the realization of the deterministic control, data processing and data logging. Furthermore, the selected hardware can support the future development application of precise timing and fast beam feedback.The software framework is designed and implemented with modularity technology which is organized by the producer-consumer design pattern and the message mechanism to accomplish the specific application. The modularity design makes it fast to transplant the modules to the other similar projects of beam diagnostics front-end control system of the heavy ion accelerator transparently. The automated variables publication of OPC UA communication protocol is implemented based on the XML configuration files. Furthermore, it is validated the feasibility of accessing the database by OPC UA variables. The unified graphical user interface(GUI) of the control system can provide the normal operation of the beam diagnostics detectors conveniently and reduce the operation frequency for physicst by remote connection compared with HIRFL.Serval applications based on the developed architecture were tested and the experimental data were analyzed which further verified the usability, scalability and portability of the beam diagnostics front-end control system for the heavy ion accelerator.The work of this paper has provided technical support on the smooth progress of the heavy-ion cancer therapy project and, furthermore, it will provide valuable design experience and technical reference for further research on the beam diagnostics control system.