A simple analytical model for the estimation of scrape-off-layer (SOL) electron temperature profile in the equatorial outer midplane (OMP) is suggested. It is demonstrated that the OMP electron temperature profile in the SOL can be approximated by a power function of the radial coordinate for constant anomalous perpendicular transport coefficients. The obtained profile gives a slower radial decrease with respect to exponential fitting, which is widely used for OMP electron temperature estimation in the near-SOL region. It is shown that the analytical profiles are in good agreement with those obtained from SOLPS-ITER simulations for the semi-detached regimes of ITER, JET and ASDEX-Upgrade. They are also in reasonable agreement with experimental Thomson scattering profiles for JET and ASDEX-Upgrade. Analysis based on SOLPS-ITER simulation shows that account of more complicated effects such as energy exchange with ions, convective energy transport, etc, can change quantitatively by factors of the order of unity, but not qualitatively, the radial electron OMP temperature profiles.
Analysis of drift effects on the tokamak power scrape-off width using SOLPS-ITER