Experiments on Magnetic Flux Ropes

Add to your list(s) Download to your calendar using vCal

• Walter Gekelman (UCLA)
• Tuesday 28 October 2025, 16:00-17:00
• MR14 DAMTP and online.

If you have a question about this talk, please contact David Hosking.

Magnetic Flux Ropes are comprised of twisted magnetic fields and currents. The pitch of the field varies with radius of the ropes. Photographs of X ray emission from the solar corona suggest the surface of the sun is littered with them. Some are arched and others expand outwards to become coronal mass ejections. Under the right conditions they become kink unstable. If two or more are close to one other the kink instability can cause them to collide and trigger magnetic field line reconnection. Flux ropes have been produced in the Large Plasma Device at UCLA and studied for over a decade. This talk will review some major results. The Quasi Seperatrix layer (QSL) , a three dimensional region in which reconnection occurs, has been measured. Volumetric measurements of inductive and space charge electric fields, plasma density, magnetic field, ion flow, electron temperature and rope current were undertaken at over 42,000 spatial locations and thousands of time steps. These were used to calculate the reconnection rate, canonical helicity, and all the terms, save resistivity, in Ohms law. Ohms law was found to be non-local. The rope magnetic fields were determined to be deterministically chaotic. Finally measured topological quantities such as twist and winding number were used to determine where in the QSL magnetic reconnection occurred.

This talk is part of the DAMTP Astrophysics Seminars series.

This talk is included in these lists:

• All CMS events
• CMS Events
• Cambridge Astronomy Talks
• Cosmology, Astrophysics and General Relativity
• DAMTP Astrophysics Seminars
• DAMTP info aggregator
• Interested Talks
• MR14 DAMTP and online
• bld31

Note that ex-directory lists are not shown.