Abstract. Impurity transport and temperature effects have been studied in FTU high temperature ECRH heated plasmas, by means of X-VUV emissions from mid-high Z elements (Fe, Ge, Mo, W). Experiments have been performed in collaboration with the Johns Hopkins University (JHU) and the Lawrence Livermore National Laboratory (LLNL). Medium-high Z elements have the advantage to not be fully ionized even at very high electron temperature (tens of keV) and to exhibit a large variety of soft X and VUV emissions very sensitive to the local plasma properties like temperatures, non thermal effects, turbulence, changes of transport properties and so on. For example X-ray emissions (L-shell) of intrinsic Mo in the plasma core, heated by ECRH power at about 8 keV during the current ramp up with a magnetic shear still negative or zero, revealed a negligible impurity transport and a central impurity peaking. Impurity transport in ECRH heated plasmas have been also studied by means of Ge and W, injected by laser ablation.
IAEA 2001