Self-consistent Simulations of Plasma-Neutral in a Partially Ionized Astrophysical Turbulent Plasma - Physics > Space PhysicsReport as inadecuate




Self-consistent Simulations of Plasma-Neutral in a Partially Ionized Astrophysical Turbulent Plasma - Physics > Space Physics - Download this document for free, or read online. Document in PDF available to download.

Abstract: A local turbulence model is developed to study energy cascades in theheliosheath and outer heliosphere OH based on self-consistent two-dimensionalfluid simulations. The model describes a partially ionized magnetofluid OH thatcouples a neutral hydrogen fluid with a plasma primarily throughcharge-exchange interactions. Charge-exchange interactions are ubiquitous inwarm heliospheric plasma, and the strength of the interaction depends largelyon the relative speed between the plasma and the neutral fluid. Unlikesmall-length scale linear collisional dissipation in a single fluid,charge-exchange processes introduce channels that can be effective on a varietyof length scales that depend on the neutral and plasma densities, temperature,relative velocities, charge-exchange cross section, and the characteristiclength scales. We find, from scaling arguments and nonlinear coupled fluidsimulations, that charge-exchange interactions modify spectral transferassociated with large-scale energy-containing eddies. Consequently, theturbulent cascade rate prolongs spectral transfer among inertial rangeturbulent modes. Turbulent spectra associated with the neutral and plasmafluids are therefore steeper than those predicted by Kolmogorov-sphenomenology. Our work is important in the context of the global heliosphericinteraction, the energization and transport of cosmic rays, gamma-ray bursts,interstellar density spectra, etc. Furthermore, the plasma-neutral coupling iscrucial in understanding the energy dissipation mechanism in molecular cloudsand star formation processes.



Author: Dastgeer Shaikh, G. P. Zank

Source: https://arxiv.org/



DOWNLOAD PDF




Related documents