Study of power load on TdeV divertor plates with an infrared camera

An infrared (IR) camera has been installed on TdeV (Tokamak de Varennes) to view both the inner and the outer divertor plates. With a finite element code (PDE Protran), the energy deposited on the plates is calculated from the surface temperature profile measured by the IR camera. The experimental results have revealed that the divertor plate temperature decreases with an increase of the main plasma density, suggesting that the plasma detaches from the divertor plates at higher plasma densities (above 4.0×1019 m−3). During divertor biasing, the heat flux increases on the plates of the `active' divertor as a result of the E×B flow. However, energy deposition can be reduced by increasing the plasma density. The neutral gas pressure in the divertor region increases strongly at higher plasma density, and appears to be correlated with the reduction in deposited energy.