A framework for the assessment and control of ITER main chamber heat loads

A control-oriented approach, based on real-time equilibrium reconstruction, has been developed to monitor power fluxes to ITER plasma-facing components (PFC). The model describes the deposited heat flux as a poloidal flux function with two main input parameters: the power exhausted across the plasma boundary and the scrape-off layer heat flux width. A module containing weighting factors accounts for the real PFC 3D geometry. These factors are obtained using a new sophisticated GUI interface, SMITER, hosting a magnetic field line tracing code permitting the import and appropriate meshing of full PFC CAD descriptions. This new methodology has been used to examine two critically important first wall (FW) power loading issues for ITER: the start-up phase at low current and power, but requiring direct contact with the inboard wall, and the case of an upward plasma shift in a diverted configuration under high power, high current H-mode burning plasma conditions, which imposes very high power loads on the upper chamber FW panels.