On strong RF plasma turbulence
Abstract
There is a sound theoretical and experimental evidence of strong nonlinear effects associated with RF heating of toroidal plasmas. In particular, concerning high power lower hybrid heating schemes, it is expected that nonlinear, strongly turbulent effects can become important. Basic features are discussed of strong RF plasma turbulence of upper hybrid and lower hybrid waves. Model equations are presented, having a Hamiltonian structure, and it is shown that in those nonlinear systems, the nonexistence of 3-D soliton wave solution is superseded by wave collapse phenomena, governed by strong ponderomotive nonlinearity. Collapse of RF waves as a unique self focusing type phenomena plays a role of an effective dissipation, determining basic microfeatures of emerging strong plasma turbulence. Moreover, it is shown that there exists a hierarchy of wave collapse regimes, starting from a weak collapse case which formally preserves zero energy into the final collapse stage and concluding with strong collapse, where the trapped RF energy remains finite. In this way, collapse classification appears significant concerning the plasma heating efficiency.
- Publication:
-
Plasma Physics and Controlled Nuclear Fusion: Next Generation Experiments in Helical Systems
- Pub Date:
- March 1990
- Bibcode:
- 1990ppcn.conf..138S
- Keywords:
-
- Plasma Control;
- Plasma Heating;
- Plasma Turbulence;
- Radio Frequencies;
- Solitary Waves;
- Toroidal Plasmas;
- Dissipation;
- Hamiltonian Functions;
- Nonlinear Systems;
- Nonlinearity;
- Plasmas (Physics);
- Self Focusing;
- Turbulence Effects;
- Plasma Physics