Laboratory Experiments on Shear Alfvn Waves, and their Relationship to Space Plasmas
نویسندگان
چکیده
Alfvn waves are ubiquitous in space plasmas and are the means by which information about changing currents and magnetic fields are communicated. Shear Alfvn waves radiated from sources with cross field scale size on the order of the electron inertial length, δ = c/ωpe, have properties which differ considerably from planar Magneto-hydrodynamic waves. Currents of cross field size , δ, are common in space plasmas. A series of experiments in the Large Plasma Device at UCLA is presented which illustrate that waves generated by small scale fluctuating currents have a parallel electric field, and radiate across magnetic field lines. Data and theory are presented for varying plasma collisionality and ratio of Alfvn speed to electron thermal velocity. Waves generated by two sources are observed to constructively interfere to produce large magnetic fields in spaital regions away from source field lines. The shear Alfvn wave is important in the Earth's auroral regions and may play a role in auroral
منابع مشابه
of Laboratory Experiments on Alfvén waves and their Relationship to Space Observations
Hannes Alfvén predicted the existence of a hydrodynamic wave in a perfectly conducting fluid in 1942. It took six years before this discovery was accepted and ten years before Alfvén waves were first observed in the laboratory. Now it is widely recognized that these waves are ubiquitous in space plasmas and are the means by which information about changing currents and magnetic fields are commu...
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