Analytical study of effects of positron density and temperature anisotropy on electrostatic ion cyclotron instability

作者：Niyat M Barati Moqadam; Khorashadizadeh S M^*; Niknam A R

来源：Physics of Plasmas, 2017, 24(3): 032103.

DOI：10.1063/1.4977803

The effects of the positron concentration and ion temperature anisotropy on the electrostatic ion cyclotron instability are studied analytically, in a magnetized electron-positron-ion plasma with temperature anisotropy, using the linear kinetic theory. Positrons and electrons are supposed to drift either in the same direction or in opposite directions relative to singly ionized stationary ions and parallel to the magnetic field. The dispersion relation of the electrostatic ion cyclotron waves is derived, and then the conditions for exciting the instability of the waves are investigated. Moreover, the condition for the marginally stable state is also studied. It is found that as the positron concentration and perpendicular ion temperature increase, the growth rate of the electrostatic ion cyclotron instability decreases, whereas the critical drift velocity increases. It is also found that for the chosen set of parameters, with electrons and positrons drifting in the same direction, the instability in the plasma is stronger than when the electrons and positrons drift in opposite directions. In addition, a comparison is made to the normal electron-ion plasma. Published by AIP Publishing.

• 出版日期2017-3