Experimental data concerning line, continuum radiation and total radiatedpower emitted by the intrinsic impurities (carbon and oxygen) in the RFXreversed field pinch have been reproduced with a one-dimensionaltime-dependent collisional radiative impurity diffusion model. Thereconstruction has been performed both in discharges with fixed current atdifferent densities and with different currents at fixed density. The resultsof the model confirm the relatively low Zeff values measured in RFXat all current levels, despite the high power flow to the wall.A diffusion coefficient of 20 m2 s-1 at the centre of theplasma, decreasing to 1 m2 s-1 at the edge, and a pinchvelocity which is outwardly directed in the central region and inward at theedge have to be used to simulate the experimental data. The diffusioncoefficient behaviour deduced for light impurities is coherent with thetransport properties deduced for the main plasma species and is consistentwith a plasma in which the confinement region is localized at the edge, wherestrong density gradients have been observed; the pinch velocity profilecharacteristics agree with the plasma radial flow resulting fromthree-dimensional nonlinear MHD codes.
Total radiation losses and emissivity profiles in RFX