mi009.tsuneta14 Posted: 2-Aug-95 Updated: 22-Aug-95 Events specified: N/A, interpretation
Saku Tsuneta
The following paper was submitted to PASJ.
lPARTICLE ACCELERATION AND MAGNETIC RECONNECTION IN SOLAR FLARES
Saku Tsuneta
ABSTRACT {\it Yohkoh} soft X-ray observations show that magnetic reconnection with attached slow shock heats the reconnected flux tubes, and that the reconnected loops subsequently filled with evaporated plasmas are seen as soft X-ray loops. The hard X-ray observations show that hard X-ray ($>$ 40--50 keV) sources are located at the footpoints of the soft X-ray loop, suggesting non-thermal electron acceleration in the loops. From these two key observations, we propose a model that fast downflow from the reconnection site collides with the loop, and that the resulting time-varying shear flow (vortices) at the loop top drives oppositely-directed field-aligned current (channels). The field-aligned current then generates the voltage drop ($\sim$ 100 keV) along the magnetic fields, generating runaway electrons. If the size of the vortices is small enough, energy and number of runaway electrons, and the time scale of acceleration are consistent with the observations. The line broadening observed with soft X-ray crystal spectrometers would be due to the vortices at the loop top rather than chromospheric evaporation.
Update 22-Aug-95
The paper submitted to PASJ was accepted. Thus, I would like to close the project.