Development of monitoring system of infrared thermometer for neutral beam injector on EAST

Neutral beam injection(NBI) is one of the most effective heating methods in fusion experiments. In the duration of injection, the unabsorbed energetic neutral particles will penetrate plasma and shot at the armor tiles, which are located at in the opposite of injection windows. The temperature of armor tiles will be increased by the shooting of unabsorbed energetic neutral particles. If the temperature rising of armor tiles is above the maximum safety temperature, they will be damaged or displaced by the thermal load. In order to ensure the process of physical experiments and the safety of armor tiles, the monitoring system of infrared thermometer has been developed. The functions of remote isolation transmission, real time monitoring, local displaying and fast protection are embed in the monitoring system.