Features of the solar X-ray bursts related to solar energetic particle events

Solar X-ray bursts appear to be most convincing signatures of particle acceleration during solar flares. It is not clear what part of this population escapes the flare region. Majority of solar energetic particles observed in the space after powerful and long lasting solar flares are probably not connected with flares and assumed to be accelerated by the shocks related to the coronal mass ejections. However, there is a significant correlation between intensity of the X-ray bursts and solar energetic particle energy. The paper considers characteristics of the X-ray bursts followed by solar energetic particle occurrences and those bursts not associated with solar energetic particles. It is shown that correlation between X-ray bursts and solar energetic particles increases with growing of X-ray burst class and solar energetic particle energy. In our opinion, it emphasizes the role of processes in the flare region for solar energetic particles occurrence.