Which particles are most common in energetic solar particles?

The most common particles found in energetic solar particles are protons. These particles are accelerated by strong magnetic fields during events such as solar flares and coronal mass ejections.1

Following protons, the composition of these energetic solar particles includes decreasing numbers of helium nuclei and heavier nuclei. While the energy spectrum of these solar particles can vary significantly between different flare events, it generally decreases more rapidly with increasing energy compared to galactic cosmic rays.1