Reconstruction of power deposition profiles using JET MkIIGB thermocouple data for ELMy H-mode plasmas

A novel technique for measuring divertor power deposition profiles using thermocouples, embedded in the target tiles, has been developed and applied to a set of JET ELMy H-mode discharges. The observation of a narrow feature in the outer target power profile, first reported in Matthews et al (Matthews G F et al 2001 J. Nucl. Mater. 290-3 668), has been confirmed. On the basis of a scan in heating power and D-puffing rate, the power decay length was found to decrease with power reaching the outer target and increase with density, λ int ~ P outer -0.45±0.10 n core 1.20±0.20 and λ int ~ P outer -0.45±0.10 n sep 0.40±0.10 . Both the power and the core/pedestal density dependencies agree with the pseudo-classical model of perpendicular transport, consistent with power removal via ion orbit losses from the edge transport barrier region.