Simulation of ITER first wall radiation heat load during the disruption

Investigation of the first wall materials behaviour under ITER off normal conditions is an important task for up to date reactor concept [1]. These investigations aimed at the evaluation of the first wall and the divertor armour damage need an estimation of the heat load at the first wall during ITER performance. Maximal heat loads are expected during the off normal events like the ELMs and the disruptions. For the simulations of disruptive radiation heat loads at plasma facing walls the FOREV-2D code has been used. The FOREV2D code was originally developed for simulations of ELM influence upon plasma facing components including the thermonuclear core contamination with vaporized and ionised first wall materials [2,3]. Previous simulations revealed that the divertor armour heat load during the disruption is drastically reduced due to formation of the plasma shield produced from the evaporated armour material close to the separatrix strike position. The plasma shield, which protects the divertor armour, is also a significant source of radiation heat load distributed over surrounding structures. After the formation of plasma shield almost all disruption energy is deposited in the shield and reradiated backwards into the vacuum vessel. The simulations have shown the feedback influence of the cold and dense carbon plasma vaporised from the divertor armour on the disruption scenario. This study analysed how are the cold plasma penetrates inside the pedestal and irradiates the thermal energy of deuterium-tritium plasma directly from the pedestal and from the core, thus without heating the divertor.