Search Publications
The inversion layer of electric fields and electron phase-space-hole structure during two-dimensional collisionless magnetic reconnection
Lefebvre, Bertrand; Chen, Li-Jen; Torbert, Roy B. +1 more
Based on two-dimensional fully kinetic simulations that resolve the electron diffusion layer in undriven collisionless magnetic reconnection with zero guide field, this paper reports the existence and evolution of an inversion layer of bipolar electric fields, its corresponding phase-space structure (an electron-hole layer), and the implication to…
Chromospheric anemone jets and magnetic reconnection in partially ionized solar atmosphere
Shibata, K.; Isobe, H.; Singh, K. A. P. +1 more
The solar optical telescope onboard Hinode with temporal resolution of less than 5 s and spatial resolution of 150 km has observed the lower solar atmosphere with an unprecedented detail. This has led to many important findings, one of them is the discovery of chromospheric anemone jets in the solar chromosphere. The chromospheric anemone jets are…
Energy budgets in collisionless magnetic reconnection: Ion heating and bulk acceleration
Belmont, G.; Aunai, N.; Smets, R.
This paper investigates the energy transfer in the process of collisionless antiparallel magnetic reconnection. Using two-dimensional hybrid simulations, we measure the increase of the bulk and thermal kinetic energies and compare it to the loss of magnetic energy through a contour surrounding the ion decoupling region. It is shown, for both symme…
Numerical simulations to study solar wind turbulence
Sharma, R. P.; Kumar, Sanjay; Kumar, Sachin +2 more
Numerical simulation of coupled equations of kinetic Alfvén wave (KAW) and ion acoustic wave is presented in the solar wind. The nonlinear dynamical equations satisfy the modified Zakharov system of equations by taking the nonadiabatic response of the background density. The ponderomotive nonlinearity is incorporated in the wave dynamics. The effe…
Plasma diffusion in self-consistent fluctuations
Belmont, G.; Aunai, N.; Smets, R. +1 more
The problem of particle diffusion in position space, as a consequence of electromagnetic fluctuations is addressed. Numerical results obtained with a self-consistent hybrid code are presented, and a method to calculate diffusion coefficient in the direction perpendicular to the mean magnetic field is proposed. The diffusion is estimated for two di…
Wavenumber spectrum of whistler turbulence: Particle-in-cell simulation
Narita, Y.; Gary, S. Peter; Saito, S.
The forward cascade of decaying whistler turbulence is studied in low beta plasma to understand essential properties of the energy spectrum at electron scales, by using a two-dimensional electromagnetic particle-in-cell (PIC) simulation. This simulation demonstrates turbulence in which the energy cascade rate is greater than the dissipation rate a…
Equations of state in collisionless magnetic reconnection
Egedal, J.; Daughton, W.; Drake, J. F. +4 more
Kinetic simulation as well as in situ measurement of reconnecting current sheets in the Earth's magnetosphere show strong electron temperature anisotropy, with the parallel electron temperature becoming several times greater than the perpendicular temperature. This anisotropy is accounted for in a solution of the Vlasov equation recently derived f…
Potential structure around the Cassini spacecraft near the orbit of Enceladus
Miloch, W. J.; Olson, J.; Ratynskaia, S. +1 more
We present the results of numerical simulations of the potential structure around an object in a streaming plasma with parameters relevant for the Cassini spacecraft passing through Saturn's plasma disk near the orbit of Enceladus. Two- and three-dimensional particle-in-cell codes have been used allowing the potential of the simulated spacecraft b…
Hall magnetohydrodynamic effects for current sheet flapping oscillations related to the magnetic double gradient mechanism
Semenov, V. S.; Erkaev, N. V.; Biernat, H. K.
Hall magnetohydrodynamic model is investigated for current sheet flapping oscillations, which implies a gradient of the normal magnetic field component. For the initial undisturbed current sheet structure, the normal magnetic field component is assumed to have a weak linear variation. The profile of the electric current velocity is described by hy…
Nonlinear effects associated with the dispersive Alfvén waves in space plasmas
Sharma, R. P.; Kumar, Sanjay
This paper presents the model equations governing the nonlinear dynamics of the dispersive Alfvén wave (DAW) in the low-β plasmas (β ≪me/mi; known as inertial Alfvén waves) applicable to solar corona and intermediate-β plasmas (me/mi≪β≪1; kinetic Alfvén waves) applicable to solar wind in Earth's magnetos…