Real-time data processing method for CO₂ dispersion interferometer on EAST

A real-time data processing system is designed for the carbon dioxide dispersion interferometer (CO₂-DI) on EAST. The system utilizes the parallel and pipelining capabilities of an field-programmable gate array (FPGA) to digitize and process the intensity of signals from the detector. Finally, the real-time electron density signals are exported through a digital-to-analog converter (DAC) module in the form of analog signals. The system has been successfully applied in the CO₂-DI system to provide low-latency electron density input to the plasma control system on EAST. Experimental results of the latest campaign with long-pulse discharges on EAST (2022–2023) demonstrate that the system can respond effectively in the case of rapid density changes, proving its reliability and accuracy for future electron density calculation.