a Dominant Role for Protons at the Onset of Solar Flares

Recent observations have cast considerable doubt on the generally accepted explanation that non-thermal electron beams transfer most of the flare energy during the onset of solar flares. In this paper the author argues that non-thermal protons in the energy region 10² - 10³ keV are a more probable energy transfer mechanism. An important consequence of this hypothesis is that the hard X-ray burst must be thermal.