How are Gamma Rays Produced During Solar Flares?
: Just as electrons are accelerated during solar flares, free protons and the nuclei of heavier elements in the solar atmosphere are also accelerated. Some accelerated protons encounter the nuclei of carbon, oxygen, neon and other elements found in the solar atmosphere. When a proton collides with one of these nuclei, the nucleus is excited to a higher energy level. The excited nucleus gives off a gamma-ray photon with a specific energy characteristic of the element involved and returns to its original energy level or ground state. Alternatively, an accelerated heavy nucleus can interact with an ambient low-energy proton and become excited to a higher energy level. It continues on at a similar velocity and emits the characteristic gamma ray as it decays back to the ground state. Because of the velocity of the heavy nucleus, the gamma-ray energy is Doppler shifted up or down, depending on whether the nucleus is moving towards or away from the observer, respectively. The process is illus
