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Kinetic Alfvén Wave(KAW)is one of the low-frequency electromagnetic fluctuations that are identifiedextensively in space plasmas by in situ observations of satellites and has been an interesting topic for discussion widelyin the fields of laboratory,space,and astrophysical plasmas because of its potential importance in plasma particleenergization.Some satellite observations show that the number density ratio of the oxygen ions to the ambient plasmais 30%~50%,sometimes,even as high as 80%.In this paper,effects of heavy ion species on KAWs are studied in alow-beta plasma.The results show that heavy ions not only considerably reduce the propagation speed of KAWs,but alsoremarkably influence the parallel component of perturbed electric field of KAWs(to the ambient magnetic field).Theratio of parallel to perpendicular components of perturbed field decreases(or increases)with the heavy ion abundancefor KAWs dominated by the electron inertial length(or by ion acoustic gyroradius),In particular,the resonant conditionof KAWs with thermal electrons is modified by the heavy ion species.
Kinetic Alfvén Wave (KAW) is one of the low-frequency electromagnetic fluctuations that are identifiedextensively in space plasmas by in situ observations of satellites and has been an interesting topic for discussion widelyin the fields of laboratory, space, and astrophysical plasmas because of its potential importance in plasma particleenergization. Some satellite observations show that the number density ratio of the oxygen ions to the ambient plasmais 30% ~ 50%, sometimes, even as high as 80% .In this paper, effects of heavy ion species on KAWs are studied in alow-beta plasma.The results show that heavy ions not only reduce the propagation speed of KAWs, but alsoremarkably influence the parallel component of perturbed electric field of KAWs (to the ambient magnetic field) .ratio of parallel to perpendicular components of perturbed field decreases (or increases) with the heavy ion abundance for KAWs dominated by the electron inertial length (or by ion acoustic gyroradius), In partic ular, the resonant condition of KAWs with thermal electrons is modified by the heavy ion species.