Ciel: Tore Supraʹs new power and particle extraction environment

Thanks to its superconducting magnet which enables potential steady plasma discharges, Tore Supra is the biggest tokamak in the world today capable of facing physics, experimental and technological issues necessary to prepare very long discharge operation of next step devices. The limited capacity of present plasma facing components (including antennas) to extract high thermal fluxes in permanent regime, the poor pumping set-up installed in the machine are today limitations which must be overcome. A new heat and particle extraction environment has thus been launched in February 1996, and is called CIEL (Inner Components and Limiter, ‘Composants Internes et Limiteur’). The paper describes this new plasma facing environment, which is designed to extract 25 MW of power, 15 MW convected on a toroidal pump limiter (TPL), the remaining radiated 10 MW being absorbed by a set of stainless steel panels and bumpers covering the inner vessel. Pumping is provided by a set of 12 quadruplets of neutralisers located below the limiter throat and connected via ducts to cryomechanical pumps. Measurement of the limiter surface temperature is devoted to a set of infrared cameras, also used for its safety.