Laboratory study of the failed torus mechanism in arched, line-tied, magnetic flux ropes

Andrew Alt, Hantao Ji, Jongsoo Yoo, Sayak Bose, Aaron Goodman, Masaaki Yamada

Research output: Contribution to journalArticlepeer-review


Coronal mass ejections (CMEs) are some of the most energetic and violent events in our solar system. The prediction and understanding of CMEs are of particular importance due to the impact that they can have on Earth-based satellite systems and, in extreme cases, ground-based electronics. CMEs often occur when long-lived magnetic flux ropes (MFRs) anchored to the solar surface destabilize and erupt away from the Sun. One potential cause for these eruptions is an ideal magnetohydrodynamic (MHD) instability, such as the kink or torus instability. Previous experiments on the magnetic reconnection experiment revealed a class of MFRs that were torus-unstable but kink-stable, which failed to erupt. These "failed-tori"went through a process similar to Taylor relaxation, where the toroidal current was redistributed before the eruption ultimately failed. We have investigated this behavior through additional diagnostics that measure the current distribution at the foot points and the energy distribution before and after an event. These measurements indicate that ideal MHD effects are sufficient to explain the energy distribution changes during failed torus events. This excludes Taylor relaxation as a possible mechanism of current redistribution during an event. A new model that only requires non-ideal effects in a thin layer above the electrodes is presented to explain the observed phenomena. This work broadens our understanding of the stability of MFRs and the mechanism behind the failed torus through the improved prediction of the torus instability and through new diagnostics to measure the energy inventory and current profile at the foot points.

Original languageEnglish (US)
Article number042901
JournalPhysics of Plasmas
Issue number4
StatePublished - Apr 1 2023

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics


Dive into the research topics of 'Laboratory study of the failed torus mechanism in arched, line-tied, magnetic flux ropes'. Together they form a unique fingerprint.

Cite this