Development of the IR interfero-polarimeter for long pulse operation at Tore Supra

In preparation to the next phase in the experimental activity of Tore Supra, the CIEL project, the internal configuration of the tokamak will be strongly modified. The main modifications will be due to the implementation of a new toroidal pumped water cooled limiter at the bottom of the machineʹs vacuum vessel, and by a new water-cooled inner wall. Moreover, the long plasma duration (≤1000 s) and the strong expected plasma radiation (up to 25 MW) impose the design of new thermally resistant in-vessel components, as the radiated power density will reach 0.01 MW/m2 on the flanges and 0.3 MW/m2 on plasma facing components. In this context, the interfero-polarimeter diagnostic will need a substantial enhancement; existing channels will be modified and five new reflected chords will be added to improve the spatial resolution. Prototypes of required in-vessel components have been designed and tested to stand plasma radiation during long pulses.