Particle simulation of Alfvén waves excited at a boundary
نویسندگان
چکیده
A particle-in-cell (PIC) code has been developed that is capable of describing the propagation of compressional and shear Alfvén waves excited from a boundary. The code is used to elucidate the properties of Alfvén wave cones radiated from sources having transverse scale comparable to the electron skin depth. Good agreement between theoretical predictions and simulation results is found over a wide range of frequencies. An investigation has been undertaken of the effect of hot ions on the Alfvén wave cones. The PIC simulations demonstrate that as the ion temperature is increased there is a reversal in the cone angle. The reversal implies that there is a cross-field focusing of the shear Alfvén waves. This is a feature which is presently being considered in studies of field-line resonances in the earth’s magnetic field. The PIC results also illustrate the damping of shear modes due to the Doppler-shifted cyclotron resonance with hot ions. © 2005 American Institute of Physics. [DOI: 10.1063/1.1832602]
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