Radiation Loads onto Plasma-Facing Components of JET

This contribution examines the impact of large type I ELMs with energies 0.25J ÷ 1.3MJ in high current H-mode JET discharges on plasma radiation and on power load to the divertor. The ELMs provoke strong radiation losses, mostly confined to the inner divertor region. Large type I ELMs with DWELM 0.72MJ show enhanced radiation losses which are associated with the ablation of carbon layers in the inner divertor. Such large ELMs are usually followed by a phase of type III ELMs with an increased radiation in the plasma core. The unmitigated disruptions exhibit small radiation fraction during the thermal quench with strong poloidal radiation asymmetry, which could cause Be melting by radiation in ITER. In dedicated experiments on massive gas injection more than 50% of the thermal energy and a significant part of the magnetic energy was converted in radiation and spread uniformly over the first walls.
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