PhD and MPhil Thesis Classes - Université Libre de Bruxelles

2Aims of the project2.1 AimsIn this thesis, the main goal is to study the anomalous transport of impurities due todrift wave microinstabilities. To study the characteristics of the unstable drift modesresponsible for the transport of impurities under fusion plasma conditions and to analyzefeedback mechanisms of the impurities on the unstable modes (chapters 3 and 4).Encouraged by the experimental observations which suggested charge dependence ofthe impurity anomalous transport characteristics (transport coefficients), unexplainedby the existing models, we follow our study on to investigating this charge dependence,and its possible underlying physical mechanism (chapter 5). As an important goal wego on to implement our impurity transport model for the transport modeling of theJET tokamak experiments, in which impurity seeding were applied. In these experimentsplasma confinement was improved by injecting Ne into the plasma edge and noimpurity accumulation in the plasma core were observed. Our aim is to find a possibleexplanation for the observed plasma behavior (chapter 7).At the end (chapter 8), to try a fresh challenge, we start looking at the problem ofturbulent and non-diffusive transport in a different framework. Using fractional kineticsand build on Levy type stable distributions, we study the plasma as a medium awayfrom the Maxwellian equilibrium conditions. We look at the effect of non-Maxelliansystem on the characteristics of the drift wave turbulence.23