Synopsis: Learning the ropes

Plasma flux ropes, which occur in events like solar flares, have been observed in experiments to bounce off each other instead of merging and annihilating.
Synopsis figure
Credit: Courtesy Tom Intrator, Los Alamos National Laboratory

In ionized environments such as the surface of the sun, magnetic field lines can become trapped in moving columns of plasma. These flux ropes can exhibit complex dynamics, and may attract or repel each other depending on the direction of current flow in the rope. In simulations and calculations, it is often assumed that if two flux ropes are attracted to one another by the Lorentz force, they will merge and annihilate. Writing in Physical Review Letters, Xuan Sun and colleagues at Los Alamos National Laboratory, US, report experimental evidence that mutually attracting flux ropes can actually bounce off each other instead of merging.

The authors studied this phenomenon at the Los Alamos Reconnection Scaling Experiment. The group created a pair of flux ropes inside the device with plasma guns and allowed the pair to evolve in three dimensions. They used a magnetic probe to map out the field strength and plasma parameters throughout the volume where the ropes were interacting. For some conditions the ropes merged as expected, but in other cases, Sun et al. observed ropes that began to merge but then separated. The Los Alamos team reports that these observations agree with a theoretical model of flux rope interaction and may have implications for understanding turbulence and energy production in astrophysical events like solar flares. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

Fluid DynamicsPlasma Physics

Previous Synopsis

Next Synopsis

Atomic and Molecular Physics

Wind blowing over an ultracold sea

Read More »

Related Articles

Focus: <i>Video</i>—Fluid Video Contest Winners
Fluid Dynamics

Focus: Video—Fluid Video Contest Winners

Swimming starfish larvae, dripping paint, and swirling gas jets are featured in the APS Division of Fluid Dynamics’ winning videos. Read More »

Synopsis: How to Make Superhydrophobicity Last
Fluid Dynamics

Synopsis: How to Make Superhydrophobicity Last

Researchers find tricks to prolong the typically short-lived water repellency of a superhydrophobic surface. Read More »

Focus: Drops Falling in Clouds Make More Drops
Fluid Dynamics

Focus: Drops Falling in Clouds Make More Drops

Experiments with a simplified version of the atmosphere show that falling drops seed many smaller droplets in their wake. Read More »

More Articles