High Time Resolution Observations of Solar Hα Flares

We present the first results of a search for fast changes of solar flare Hα emission correlated in time with variations of hard X‐ray fluxes. For numerous flares we have found good time correlations between short variations of the Hα emission of selected bright flaring kernels and the variations of the X‐ray flux; some subtle variations of both light curves are simultaneous to a fraction of second. Our results are consistent with a model of a highly spatially and temporally fragmented primary flare energy source as well as with theoretical predictions of very short cooling time of the chromospheric material.