Average height of the hard X-ray footpoint sources in solar flares Original Research Article

Hard X-ray footpoint sources in solar flares are produced by electrons precipitating along a magnetic loop. Using the Yohkoh Flare Catalogue covering the whole Yohkoh mission period, we determined an accurate position of hard X-ray sources in many flares and then selected events containing footpoint source to derive the source height. We revealed that accelerated electrons emitting hard X-rays (13–93 keV) lose their energies within about 1000 km and the emitting region becomes dense with the increasing electron energy. We briefly show analysis and results of the height of hard X-ray emitting region.