Flows in Confined Plasmas
Flow Induced Phenomena in Magnetically Confined Plasmas
Tech Area / Field
- PHY-PLS/Plasma Physics/Physics
- FUS-MCS/Magnetic Confinement Systems/Fusion
- FUS-PLA/Plasma Physics/Fusion
3 Approved without Funding
Tbilisi State University / Institute of Physics (Ge), Georgia, Tbilisi
- University of Tokyo / Graduate School of Frontier Sciences, Japan, Tokyo\nUniversity of Texas at Austin / Institute for Fusion Studies, USA, TX, Austin
Project summaryThe dynamics of flowing multi-species plasmas embedded in magnetic fields has attracted considerable attention in view of its potential applications to fusion, to the energetic technology, space weather forecast and ecology. Studies carried out on the flowing plasmas connect the fusion research and basic (plasma and astronomy) research. The investigation of flow-induced phenomena in magnetically confined plasmas will have a profound bearing on the success of future fusion experiments like ITER. The fast intermittent convective plasma transport in the edge region of Tokamak offers clear evidence of ordered structures formation. Modern improved instrumental facilities provide observational evidence of fine structuring of Stellar Atmospheres, Radiation coming from various astrophysical objects. It is already possible to model the Extra-Galactic Medium and Astrophysical Jets. Plasma confinement experiments, launching, acceleration and collimation of relativistic jets, large scale magnetic field openings in stellar atmospheres as well as the escape of particles and fast outflows from various systems are good examples of the crucial role of magnetic fields in creation of steady or quasi-steady structures and determining the nature of various dynamical processes (heating, for example) taking place in flowing plasmas. Structure formation dynamics is found to be strongly affected by the zonal-flow generation and macroscopic magnetic field generation, dissipative processes, vorticity and rotational effects, density and temperature inhomogeneities, velocity shear-induced mode-couplings, instabilities and flow-wave interactions in kinematically complex plasma outflows. Research in these areas has acquired tremendous importance and interest. The integrated theory and modeling of this huge variety of processes requires a re-examination of existing theoretical models and conventional approaches.
The main goal of this project is to systematically explore the linear and nonlinear phenomena arising out of the interaction of the magnetic fields with sheared plasma flows. This magneto-fluid coupling, perhaps, lies at the heart of dynamical phenomena which determine, for example, the range of parameters favorable for the high confinement of plasmas, for ordered structure formation and for the excitation of instabilities; it also controls the energy transformation mechanisms for large field generation, heating and acceleration. The principal objective of this project is to carry out theoretical investigations on: structure formation dynamics in inhomogeneous flowing magnetized plasmas (including boundary layer dynamics in tokamaks); plasma flow generation, its stability and particle acceleration due to magneto-fluid coupling; macroscopic magnetic field generation; wave-dynamics in compressible multi-species plasmas in the presence of vortical shear flows; L-H transition dynamics in tokamaks. Formulation of the conditions under which improved high-confinement plasma is achieved is one of our particular interests.
The formulation of the proposed project represents the natural development of previous research and experience of the project participants who already are members of or in close collaboration with many leading groups in nonlinear plasma physics and magneto-hydrodynamics (MHD). The group’s research was supported by International Science Foundation (in 1994-96), INTAS (in 1994, 1997-2000), ISTC (in 2002-2005, Project G-663). Collaborating actively in above listed projects, the research inpiduals, involved in the present project have expertise in the following fields:
- Nonlinear MHD of multi-fluid plasmas.
- Plasma astrophysics, including the study of astrophysical plasma flows.
- Nonlinear optics and relativistic plasma physics.
- Numerical modeling and simulation of two-fluid dissipative plasmas and nonlinear electromagnetic radiation dynamics in highly dispersive media
- Turbulent Tokamak plasmas.
The senior members of team enjoy high international reputation with a large number of excellent and well-recognized publications. The team is unique with strong background in nonlinear electrodynamics, MHD, astrophysics and wave propagation as well as computer simulations. Thus, the proven competence and expertise of team members guarantees the successful implementation of the proposed project.
The proposed project will yield "dual products": one is the development of a solid theoretical basis to predict various effects of shear flows in a fusion plasma, which is extremely important to optimize the fusion core. The other is the dissemination of the high-level notions to be developed by the theoretical and experimental studies of fusion plasma physics. The expected results are likely to span: 1) development of new and useful knowledge about the characteristics of flow-induced phenomena in high-confinement plasmas (ordered structure formation dynamics in multi-species magnetically confined compressible plasmas, advancing the understanding of L-H transition in tokamaks); 2) delineation of new mechanisms and conditions for efficient flow/jet-like outflow generation and particle acceleration, particle escape from close field line regions (due to magneto-fluid coupling); 3) the evolution of macroscopic magnetic fields and instabilities, heat-transfer phenomena in vortical flowing plasmas; and 4) the theory of shear-flow induced wave-couplings. In addition to its intrinsic scientific value, these research activities will have important applications to many laboratory and astrophysical systems. On the basis of expected results team suggests the design of new simulation experiments for: the boundary layer self-organization in tokamaks, dynamical flow and macroscopic field generation.
The project scope of research activities will include a comprehensive study of various linear and nonlinear effects that take place in magnetically confined plasmas in the presence of flows - compressible multi-species plasmas fall within the scope. The principal focus will be on the role of the magneto-fluid coupling in the self-organization of flowing magnetized systems. Although several aspects of the magneto-fluid dynamics are a necessary part of any standard treatment, there are a host of magneto-fluid phenomena (described earlier) whose scope is yet to be chartered. Both analytical and numerical methods will be harnessed to study, for instance, the self-organization processes that lead to the formation of long-lived and ordered structures.
Foreign collaborators will take part in the joint scientific meetings and seminars and in the discussions and joint publications of the research results. In active collaboration with them, the project participants plan to design new experiments and suggest new possible directions in the field of investigation.
The present project concerns: theoretical and computational investigations of the flow-induced nonlinear phenomena in different kind magnetically confined plasmas including those found in fusion devices aiming the formation of equilibrium structures, generation/acceleration of plasma flows, dynamics of edge layer in Tokamaks, the energetic outflows due to the magneto-fluid coupling, linear and nonlinear wave-couplings and mode-conversion. The numerical simulations will also be used to solve the 3D equations that are derived in the framework of the project. The methodology of the proposed research is based on the analysis of the economical numerical schemes of the 3D equations such as varying spatial dimension methods, equation splitting method, sum approximation method, and etc. For each of the tasks and sub-tasks of proposed research a detailed scientific description of the research program is given below.
The realization of the given project will provide the possibility of peaceful fundamental scientific and research activity for scientists involved in this project.
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