Speiser and Dahu orbits: the trappings that heat you up!
Time evolution of two current sheets profiles (colored surfaces) that move close to each other, increasing their intensities (from violet to yellow) and merges at the late stage.
The lines represent the trajectories of sample ions. The white ones (not trapped) do not increase their energy. The colored trajectory, instead, is trapped bouncing between the confining approaching current profiles, increasing its kinetic energy from yellow to green, evolving alternatively from Speiser and Dahu orbits.
January 22, 2019
Fully kinetic turbulence in collisionless magnetorotational instability
The figure shows magnetic field vortex structures in a 2D simulation of plasma in a collisionless accretion disk. The simulation, obtained with OSIRIS PIC code, shows the space distribution for the magnetic field along the radial and the vertical directions.
These vortexes appear at the surface of change of sign (red/orange positive-blue/green negative) of the magnetic field and are essential for the activation of parasitic instabilities which trigger the turbulent regime of the plasma.
Giannandrea Inchingolo, et al., Fully kinetic large-scale simulations of the collisionless magnetorotational instability. The Astrophysical Journal, 859(2):149, 2018.
July 1, 2018