Rayleigh-taylor instability in solar prominences as a mechanism for dXouble-ribbon flares

In this paper, the energy storage for a spotless two-ribbon flare is discussed with reference to the morphology of the chromospheric fibrils surrounding a filament prior to the flare. Also, on the basis of the Kippenhahn-Schluter model of filaments, we discuss the instability of magnetic structure in these filaments. We found that once the gradient of the magnetic field or the curvature of the magnetic “trough” exceeds certain critical value, the Rayleigh-Taylor instability will be triggered off, leading to the sudden disappearance (Disparition Brusque) of the filament. At the same time, a neutral current sheet will be formed in the field with magnetic flux concentrated on both sides of the filament. Rapid reconnection of the field lines then lead to the onset of a two-ribbon flare.