Electron temperature measurements and heat transport improvement in the RFX-mod experiment.

Electron temperature profiles at about 1keV have been measured in the RFX-mod experiment during the recent high plasma current campaign (I$_{p}>$1.2MA, n$_{e}\sim $4$\cdot $10$^{19})$: peaked Te profiles, obtained through the Thomson scattering diagnostic, are characterized by a steep gradient in the core during the quasi-single helicity (QSH) state. The formation of well defined magnetic flux surfaces during QSH states determines a reduction of thermal heat conductivity, whose estimate is essential to quantify this transport improvement. We apply the M1TeV code [1] to various experimental scenarios in order to estimate heat diffusivity, then also calculating electron confinement time: in this study, we consider the effect of the increase of plasma current and also of eventual external current drive. \newline [1] F.Porcelli \textit{et al.}, Phys. Rev. Lett. 82, 1458 (1999).