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Detailed Reference Information |
Ofman, L., Davila, J.M., Nakariakov, V.M. and Viñas, A.-F. (2005). High-frequency Alfvén waves in multi-ion coronal plasma: Observational implications. Journal of Geophysical Research 110. doi: 10.1029/2004JA010969. issn: 0148-0227. |
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We investigate the effects of high-frequency (of order ion gyrofrequency) Alfv¿n and ion-cyclotron waves on ion emission lines by studying the dispersion of these waves in a multi-ion coronal plasma. For this purpose we solve the dispersion relation of the linearized multifluid and Vlasov equations in a magnetized multi-ion plasma with coronal abundances of heavy ions. We also calculate the dispersion relation using nonlinear one-dimensional hybrid kinetic simulations of the multi-ion plasma. When heavy ions are present the dispersion relation of parallel propagating Alfv¿n cyclotron waves exhibits the following branches (in the positive Ω - k quadrant): right-hand polarized nonresonant and left-hand polarized resonant branch for protons and each ion. We calculate the ratio of ion to proton velocities perpendicular to the direction of the magnetic field for each wave modes for typical coronal parameters and find strong enhancement of the heavy ion perpendicular fluid velocity compared with proton perpendicular fluid velocity. The linear multifluid cold plasma results agree with linear warm plasma Vlasov results and with the nonlinear hybrid simulation model results. In view of our findings we discuss how the observed nonthermal line broadening of minor ions in coronal holes may relate to the high-frequency wave motions. |
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BACKGROUND DATA FILES |
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Abstract |
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Keywords
Solar Physics, Astrophysics, and Astronomy, Corona, Solar Physics, Astrophysics, and Astronomy, Coronal holes, Space Plasma Physics, Charged particle motion and acceleration, Space Plasma Physics, Kinetic and MHD theory, Space Plasma Physics, Kinetic waves and instabilities, coronal holes, multi-ion plasma, multifluid model, hybrid model, Vlasov dispersion relation, ion cyclotron waves |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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