Fast Measurements of the Limiter Surface Temperature and the Heat Flux onto the Limiter in the T-11M Tokamak by Using an IR Radiometer

The limiter surface temperature is measured with a high-speed IR radiometer ((lambda)=3–6(mu)m) during a T-11M tokamak discharge. The IR radiometer was absolutely calibrated under steady-state operating conditions: the limiter was heated by a special inner heater, and the limiter temperature was measured with a thermocouple. Based on these measurements, the heat fluxes from the plasma onto the limiter surface during the discharge are determined. The measurement technique is discussed, and the data on the limiter surface temperature and the heat flux to the limiter for different regimes of the T-11M operation are presented.