High-Speed Optical Signal Processing System Based on DSP for Neutral Beam Injector on EAST

Abstract

Neutral Beam Injection (NBI) is one of the main plasma heating methods in nuclear fusion devices. To prevent the device from irreversible damage, all the status signal acquisition and transmission must meet high voltage isolation, fast-reaction and high reliability requirements. DSP performs well at complicated algorithms computing and meets the real-time requirements, but it is poor at parallel processing. FPGA is good at combination logic and sequential logic control. To meet the EAST-NBI control system experimental operational requirements, DSP and FPGA architecture is taken in this design, which converts the optical signal to high-precision analog signal to output. This paper analyzes the requirement of high-speed optical signal processing system based on DSP for EAST-NBI and introduces the detail modules designs, including seven modules: optical signal receiving and conversion interface circuit, FPGA decoding interface circuit, OMAP processing interface circuit, DAC interface circuit, Ethernet interface circuit, serial port interface circuit and amplification interface circuit.

The Implementation of Real-Time Plasma Electron Density Calculation Based on FPGA for Tokamak Devices

“…If the actual phase value increases by more than p, the phase overflow is called a positive shift. On the contrary, If the actual phase value decreases by less than -p, the phase overflow is called a negative shift [10]. Theoretically, when the shift occurs, the actual phase difference result can be obtained by directly adding or subtracting the shift threshold to the current signal value.…”

“…The response delay is longer, and its response time is 80% delayed compared with that of the hardware phase meter. A field-programmable gate array (FPGA), with multiple internal modules which can compute respectively at the same time, is widely used in signal transmission and matrix algorithms in Tokamak devices [9,10].…”