Laboratory nano-flares generated from multiple braided current loops

Braided loop structures are observed in a new Caltech lab experiment replicating solar coronal loops. A single strand of a braided magnetic structure is observed to undergo a magnetic Rayleigh-Taylor Instability (MRTI) driven by the effective gravity of hoop force acceleration.  A burst of keV X-rays and a ~ 4 kV inductive voltage spike are detected simultaneously with the MRTI. These observations reveal a clear MHD to non-MHD path for generating solar energetic particles and X-ray bursts: a solar flux rope is a braid of current-carrying fractal-scale flux ropes with the finest braid strand being larger than ion skin depth d_i or β^-1/2 d_i.  Current path curvature creates a hoop force accelerating strands creating a large effective gravity that can cause a fast-growing MRTI to choke the strand to less than d_i or β^-1/2 d_i. This choking is presumed to cause kinetic instabilities that increase the local effective resistivity. This effective opening switch abruptly reduces the current in the strand and large-scale exterior circuit inductive energy dumps into the increased resistivity region. The inductive voltage spike LdI/dt accelerates charged particles to extreme energies, and electron bremsstrahlung produces X-ray bursts.