Speaker
Description
To measure plasma density and provide real-time feedback for the control system, we have established a carbon dioxide dispersion interferometer (CO2-DI) system on the EAST tokamak device. Due to the low efficiency of the frequency-doubling crystal, the power of the second harmonic is extremely low. To obtain accurate interference information, it is necessary to use a lock-in amplifier to acquire modulation signals at 50k and 100k and process the intensity of this signal to obtain plasma density.
In our design, a lock-in amplifier module consists of two main components, the lock-in amplifier and the real-time data acquisition system. A dual-phase lock-in amplifier is designed. By two phase channels, the dual-phase lock-in amplifier can better handle complex signals and provide more comprehensive phase information. This capability makes it suitable for extraction of weak signals in CO2-DI. The real-time data processing system is implemented on a development board, utilizing Xilinx FPGA for digital signal processing and interfacing with the backend for output. The module is applied in CO2-DI to extract small signals and perform real-time data processing. We cross-validated the processed density data with results obtained from two other interferometers. The results indicate that the entire system has successfully obtained valid and verifiable electron density data.
| Minioral | Yes |
|---|---|
| IEEE Member | No |
| Are you a student? | No |
