The Electronics Design of Real-Time Feedback Control System in KTX

A feedback control system has been designed for Keda Torus eXperiment (KTX) to achieve the following goals: 1) 3-D plasma stability control and 2) improvement of plasma discharge quality. The real-time electronics system which is the key unit of this feedback control system helps to resolve the lack of high-speed transmission and real-time processing capability of the previous data acquisition (DAQ) system. The electronics system is implemented in PXI Express using a modular, distributed architecture. Field-programmable gate array (FPGA) is the core component of the electronics system. This article describes in detail the reasons for the choice in the hardware components. Optical communication has been evaluated for real-time communication by using the Aurora protocol. Measurements have been executed on a prototype system. Results from several tests comparing the performance of different solutions are also provided. 2-D spatial Fourier analysis based on FPGA is first used on the reversed field pinch (RFP) fusion device. Results indicate that the system can control the whole process and calculation in low latency.