Impurity behavior and electron-temperature evolution during ECR heating by an extraordinary wave in the L-2 stellarator

Radial profiles of the intensities of ion lines of the most abundant impurities (oxygen, carbon, and iron) and their evolution in the course of the heating have been measured spectroscopically during experiments on electron cyclotron heating of the plasma by an extraordinary wave in the L-2 stellarator. Comparison of the experimental results with the results of a numerical simulation with a code incorporating ionization, recombination, and charge exchange as well as the transport of impurity ions shows that, in contrast with ohmic heating, the experimentally observed fluxes of impurties during ECR heating of a current-free plasma can be explained by neoclassical theory. It is not necessary to introduce anomalous transport