Pulsating Magnetic Reconnection Driven by Three-Dimensional Flux-Rope Interactions

Area of Science:

• Plasma Physics
• Laboratory Astrophysics
• Magnetohydrodynamics

Background:

• Magnetic reconnection is a fundamental process in plasma physics, crucial for phenomena like solar flares and laboratory plasma confinement.
• Understanding reconnection dynamics requires detailed measurements of electromagnetic fields and plasma behavior.

Purpose of the Study:

• To investigate the dynamics of magnetic reconnection in a laboratory setting using two interacting magnetic flux ropes.
• To directly evaluate field-line mapping quantities and measure the nonlinear reconnection rate using experimental data.

Main Methods:

• Utilized a laboratory experiment with two magnetic flux ropes near the kink instability threshold.
• Acquired volumetric three-dimensional magnetic and electric field data.
• Computed quasipotential by integrating the parallel electric field along magnetic field lines.

Main Results:

• Observed periodic bursts of magnetic reconnection synchronized with the ropes' rotational and bouncing motion.
• Identified quasiseparatrix layers (QSLs) between the flux ropes during reconnection events.
• Demonstrated a correlation between QSLs and enhanced quasipotential, indicating active reconnection and providing a direct measure of the nonlinear reconnection rate.

Conclusions:

• Provided direct experimental evidence of magnetic reconnection occurring within QSLs.
• The parallel electric field in the QSL is primarily sustained by electron pressure, with a possible contribution from resistivity.
• Established a link between macroscopic flux rope dynamics and microscopic reconnection processes.