Unique features of parallel whistler instability in a plasma with anisotropic Cairns distribution

作者：Malik M Usman^*; Masood W; Mirza Arshad M

来源：Physics of Plasmas, 2017, 24(10): 102120.

DOI：10.1063/1.4998774

In this paper, whistler waves propagating parallel to the ambient magnetic field with electron temperature anisotropy are investigated by employing the kinetic theory of plasmas. The electron distribution function is considered to follow the Cairns distribution. The dispersion relation for the whistler waves with Cairns distribution is derived, and the condition for the onset of instability is also obtained. It is found that the Cairns distribution significantly modifies the instability condition for the growth of whistler instability. The comparison of the dispersion characteristics and the growth rate with Maxwellian distribution is also made, and it is observed that Cairns distributed electrons yield a higher growth rate in comparison to their Maxwellian counterparts. It is also shown that unlike the kappa distribution where parallel electron beta was found to play the key role, whistler instability with Cairns distributed electrons shows a greater sensitivity towards electron temperature anisotropy. It is shown that the real frequency of the whistler waves shows a greater dependence on the choice of parallel electron beta. Interestingly, it is found that a particular combination of parallel electron beta and electron temperature anisotropy is deleterious for the whistler instability. Published by AIP Publishing.

• 出版日期2017-10