Acceleration of Plasma Flows Due to Inverse Dynamo Mechanism

The ”inverse–dynamo” mechanism — the amplification/generation of fast plasma flows by short scale (turbulent) magnetic fields via magneto–fluid coupling is recognized and explored. It is shown that large–scale magnetic fields and flows are generated simultaneously and proportionately from short scale fields and flows. The stronger the short–scale driver, the stronger are the large–scale products. Stellar and astrophysical applications are suggested. Subject headings: acceleration of particles — magnetic fields — MHD — instabilities — Stars: magnetic fields — Stars: atmospheres — Stars: chromospheres — Stars: coronae — ISM: magnetic fields The generation of large scale magnetic fields (primarily from short scale velocity fields) defines the standard ”dynamo” mechanism. The dynamo action seems to be a very pervasive phenomenon; in fusion devices as well as in astrophysics (stellar atmosphere, MHD jets) one sees the emergence of macro–scale magnetic fields from an initially turbulent system. The relaxation observed in the Reverse Field pinches is a vivid illustration of the dynamo in action. Search for interactions that may result in efficient dynamo action is one of the most flourishing fields in plasma astrophysics. The myriad phenomena taking place in the stellar atmospheres (heating of the corona, the stellar wind etc.) could hardly be understood without knowing the origin and nature of the magnetic field structures weaving the corona. Electronic mail: [email protected] Electronic mail: [email protected] [email protected]