Interplay of parallel electric field and trapped electrons in kappa-Maxwellian auroral plasma for EMEC instability

• 来源期刊: 理论物理通讯（英文版）
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: ATOMIC,MOLECULAR, OPTICAL (AMO) AND PLASMA PHYSICS, CHEMICAL PHYSICS
• 页码范围: 78-86
• 页数: 9页
• 语种: 英文

摘要

In this paper,propagation characteristics of electromagnetic electron cyclotron(EMEC)waves based on kappa-Maxwellian distribution have been investigated to invoke the interplay of the electric field parallel to the Earth's magnetic field and auroral trapped electrons.The dispersion relation for EMEC waves in kappa-Maxwellian distributed plasma has been derived using the contribution of the parallel electric field and trapped electron speed.Numerical results show that the presence of the electric field has a stimulating effect on growth rate,which is more pronounced at low values of wave number.It is also observed that as the threshold value of trapped electron speed is surpassed,it dominates the effect of the parallel electric field and EMEC instability is enhanced significantly.The electric field acts as another source of free energy,and growth can be obtained even in the absence of trapped electron drift speed and for very small values of temperature anisotropy.Thus the present study reveals the interplay of the parallel electric field and trapped electron speed on the excitation of EMEC waves in the auroral region.