Development of a real-time tangential dispersion interferometer system and its first results for density feedback on EAST

• Developed a tangential dispersion interferometer (TDI) system for EAST to enhance density feedback accuracy. • Employs two horizontal windows for tangential density measurements, ensuring stable signals and enhanced reliability. • The TDI system on EAST demonstrates its advantages in density feedback control and suitability for future high-density burning plasma devices. A horizontal tangential dispersion interferometer (TDI) system has been developed for the Experimental Advanced Superconducting Tokamak (EAST) to enhance the accuracy of density feedback. This system offers several advantages, including vibration insensitivity and a reduced risk of fringe jump errors compared to far-infrared interferometers, making it more suitable for density feedback control. The TDI system uses two horizontal windows for tangential density measurements. Experimental results demonstrate that the TDI provides stable signals and enhances overall system reliability. Statistical analysis demonstrates that the TDI data have a measurement success rate of approximately 96%. Moreover, the temporal resolution of the system, at 20 µs, meets the requirements for real-time feedback control on EAST. The system employs a modified density real-time processing system and has been evaluated for density feedback control. During density feedback control experiments, the TDI system demonstrated notable advantages and stability, making it more suitable for future high-density burning plasma devices.