N.N. Gorelenkov
Principal Research Physicist
Princeton Plasma Physics Laboratory, Princeton University
"Energetic Particles and Alfven Instabilities in Magnetic Fusion"
Ions with energies above the plasma ion temperature (or super thermal) are created in both present day laboratory and natural plasmas. Their energy is utilized in laboratory experiments to heat the plasma to compensate for the energy loss. Sources of super thermal ions are direct injection via neutral beams, RF heating and fusion reactions. Being super thermal, ions have the potential to induce instabilities of a certain class of Magnetohydrodynamic (MHD) cavity modes, in particular, various Alfven Eigenmodes. It is an area where ideal MHD and kinetic theories can be tested with great accuracy. There are two motivations to study the energetic ion (EI) interactions with MHD modes. One is the possibility of controlling the heating channel of present and future tokamak reactors via EI transport. In some extreme circumstances, uncontrolled instabilities lead to vessel wall damages. The second is the possibility of using the observations of EI-induced instabilities for plasma diagnostics such as MHD spectroscopy. In the talk, I will review some experimental and theoretical advances and the developments of the predictive tools in the area of EI wave interaction. Some recent important results and challenges will also be discussed. The many predicted instabilities pose a challenge for ITER, where intense alpha-particle populations are likely to excite various Alfven modes.
Hosted by Prof. Thomas Pedersen
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