Solar wind collisional heating

Abstract

To properly describe heating in weakly collisional turbulent plasmas such as the solar wind, inter-particle collisions should be taken into account. Collisions can convert ordered energy into heat by means of irreversible relaxation towards the thermal equilibrium. Recently, Pezzi et al. (Phys. Rev. Lett., vol. 116, 2016, p. 145001) showed that the plasma collisionality is enhanced by the presence of fine structures in velocity space. Here, the analysis is extended by directly comparing the effects of the fully nonlinear Landau operator and a linearized Landau operator. By focusing on the relaxation towards the equilibrium of an out of equilibrium distribution function in a homogeneous force-free plasma, here it is pointed out that it is significant to retain nonlinearities in the collisional operator to quantify the importance of collisional effects. Although the presence of several characteristic times associated with the dissipation of different phase space structures is recovered in both the cases of the nonlinear and the linearized operators, the influence of these times is different in the two cases. In the linearized operator case, the recovered characteristic times are systematically larger than in the fully nonlinear operator case, this suggesting that fine velocity structures are dissipated slower if nonlinearities are neglected in the collisional operator.

References in corpus (15)

• Observation of inertial energy cascade in interplanetary space plasma
• Small Scale Energy Cascade of the Solar Wind Turbulence
• Turbulence in the sub-Alfvénic solar wind driven by reflection of low-frequency Alfvén waves
• Differential kinetic dynamics and heating of ions in the turbulent solar wind
• The Structure of Plasma Heating in Gyrokinetic Alfvénic Turbulence
• Solar wind turbulence from MHD to sub-ion scales: high-resolution hybrid simulations
• Nonlinear and Linear Timescales near Kinetic Scales in Solar Wind Turbulence
• Collisional Thermalization of Hydrogen and Helium in Solar Wind Plasma
• The dissipation of solar wind turbulent fluctuations at electron scales
• Proton Heating in Solar Wind Compressible Turbulence with Collisions between Counter-propagating Waves
• Revisiting a classic: the Parker-Moffatt problem
• Colliding Alfvénic wave packets in MHD, Hall and kinetic simulations
• Collisional effects on the numerical recurrence in Vlasov-Poisson simulations
• Fluid moments of the Landau collision operator
• Uniform derivation of Coulomb collisional transport thanks to Debye shielding

Cited by in corpus (14)

• Turbulence-driven ion beams in the magnetospheric Kelvin-Helmholtz instability
• Radial evolution of the solar wind in pure high-speed streams: HELIOS revised observations
• Dissipation measures in weakly-collisional plasmas
• Cascades and Dissipative Anomalies in Nearly Collisionless Plasma Turbulence
• Local energy transfer rate and kinetic processes: the fate of turbulent energy in two-dimensional Hybrid Vlasov-Maxwell numerical simulations
• Energy conversion in turbulent weakly-collisional plasmas: Eulerian Hybrid Vlasov-Maxwell simulations
• Fluid simulations of plasma turbulence at ion scales: comparison with Vlasov-Maxwell simulations
• Proton-proton collisions in the turbulent solar wind: Hybrid Boltzmann-Maxwell simulations
• Kinetic Entropy-Based Measures of Distribution Function Non-Maxwellianity: Theory and Simulations
• Sign singularity of the local energy transfer in space plasma turbulence
• Fourier-Hermite decomposition of the collisional Vlasov-Maxwell system: implications for the velocity space cascade
• Energy transport during 3D small-scale reconnection driven by anisotropic plasma turbulence
• Local and global properties of energy transfer in models of plasma turbulence
• Current sheets, plasmoids and flux ropes in the heliosphere. Part II: Theoretical aspects