Loop-top Turbulence

Non-thermal Signatures of a Flare Loop-top and their Implications for Turbulence and Electron Acceleration

We found evidence for non-thermal signatures in the flare loop-top region consistent with the presence of turbulence and acceleration of electrons. Below is a movie of the emission of Fe XXI 1354.1 Å from the flare loop-top region observed by the IRIS satellite.

We found the power dissipated by plasma turbulence, indicated by the decay in non-thermal broadening, matched the rate of energy dissipation of nonthermal electrons deposited into the chromosphere. This finding suggests a connection between turbulence and electron acceleration.

The correlation between turbulence and electron acceleration was further corroborated by radio emission measured by EOVSA, which was co-spatial and co-temoral with the Fe XXI loop-top emission. Such radio emission is characteristic of gyro-synchrotron emission from non-thermal electrons accelerated in the flare loop-top region.