Influence of the temperature of the photosphere and deeper layers of the Sun on the spectra of gamma quanta with energies above 511 keV during solar flares

Abstract

Gamma-ray quanta, which occur during solar flares due to the interaction of accelerated protons with the photosphere and deeper layers of the sun, enter interplanetary space from a thickness of several tens of g/cm2. In the presented work, gamma quanta with energies of more than 511 keV are considered. This makes it possible to exclude from consideration the dependence of the probability of ortho- and parapositronium formation on the temperature and density of the solar matter. And also do not consider the probability of annihilation by two or 3 gamma quanta. Thus, the reactions of thermal neutrons remain dependent on the temperature. As the ambient temperature increases, the average number of elastic neutron scattering before capture increases. This leads to a more likely penetration of neutrons to a greater depth or their departure into the interplanetary space. The high temperature of the Sun below the photosphere may be one of the reasons for the absence of the 2.223 MeV line in solar flares with registered protons in the PAMELA and AMS2 experiments. Using the GEANT4 package, the spectra of gamma-quanta arising in nuclear interactions are calculated. The temperature-dependent features of the gamma-ray spectra are discussed.