RADIATIVE PLASMAS IN TDEV

The main aspects of radiative plasma experiments carried out in the LH -heated TdeV tokamak are summarized. D-2, N-2 and Ne puffing, and dive rtor biasing, are assessed in terms of their ability to increase edge and divertor radiative losses and reduce neutralizer plate heat loads. Detailed patterns of radiation and plate power deposition are compare d. Combined N-2 and D-2 puffing gives the best results. Biasing enhanc es divertor radiation but also causes an increase in power conducted a nd convected to one of the divertor legs. The improvements obtained ar e still insufficient due to disruptive instabilities that appear at hi gh impurity puffing rates. The instability is triggered at the edge wi th N-2 and in the core with Ne.