Development of data acquisition and protection system of infrared thermometer for EAST NBI

Neutral Beam Injection (NBI) is one of the heating methods in tokamaks. In the process of injection, the neutral particles will not be absolutely absorbed by plasma. The unabsorbed neutral particles penetrate plasma and shot at inner wall tiles. It will cause the temperature increases of armor tiles that are placed in the opposite of NBI injection windows. In order to ensure the armor tiles work during safe interval, the data acquisition and protection system of infrared thermometer has been developed. The system achieves the functions of isolated transmission, remote monitoring, and fast protection. The response time of data acquisition and protection system is less than 5μs, and the transmission rate of the system is 5kHz. The quick response and stability of the data acquisition and protection system have been confirmed in practice.