Experimental study of the spreading of the deposited heat flux on the toroidal pumped limiter of Tore Supra

摘要

Understanding heat flux deposition processes is essential for the design of the plasma facing components allowing reliable high power steady state plasma operations. Due to the magnetic configuration of Tore Supra, the heat flux pattern deposited on the Toroidal Pumped Limiter (TPL) exhibits, every 20° (from one toroidal coil to the following), two heat flux peaks separated by the plasma contact point where magnetic field lines graze the surface (incident angle typically ≤1°). The heat flux deposition pattern depends of several plasma parameters (assuming the TPL castellated tiles are perfectly plane, no tile misalignments): the geometry of the magnetic, field lines (characterized by safety factor q), the heat flux decay length (λ_q) and also the ion Larmor radius (r_L which increases the spreading of the heat flux on the TPL due to gyro-radius effects. Recent Tore Supra experiments have been carried out with λ_q varying between 1.5 and 3cm and with r_L varying between 0.5 and 0.85mm.