Unstable twisted modes in interpenetrating space plasmas containing superthermal species

Publication date: Available online 11 June 2019Source: Physics Letters AAuthor(s): S. Bukhari, S.A. Khan, S. AliAbstractThe electrostatic twisted modes with orbital angular momentum and associated kinetic instability are studied in a permeating space plasma containing streaming particle species. The plasma containing superthermal electrons and ions is modeled by using a non-gyrotropic Kappa distribution function which penetrates through a relatively slow moving (static) plasma and gives rise to dispersion, damping and growth of ion-acoustic mode under various conditions. Using the Vlasov-Poisson model, the solutions of twisted modes are defined by Laguerre-Gaussian mode functions, which decompose the plasma distribution function and electric field into components characterized by the axial and azimuthal wave numbers. The dielectric constant is derived and analyzed for threshold condition of wave dispersion and instability in the presence of helical electric field with illustrations. The wave excitations due to penetration of solar wind into cometary clouds or interstellar electron-ion plasmas is examined.

Source: Physics Letters A - June 12, 2019 Category: Physics Source Type: research