Detection and study of the 2.22 MeV Emission Line in the Sun Deuterium formation process

Abstract

The formation of deuterium in the Sun is one of the events that take place all the time as a result of various processes. In particular, the fusion of a neutron with a hydrogen atom nucleus (proton) results in the creation of a deuterium atom nucleus and the emission of a gamma ray with a very characteristic energy of 2.22 MeV. By detecting these gamma rays on Earth we can infer that the deuterium was produced in the Sun and thus obtain direct information about its production in this source. We have planned, designed, simulated - in GEANT4 -, constructed and characterized a gamma ray detector to study this 2.22 MeV line and its emission process. According to our simulation, we can use two veto detectors (using scintillating materials) and a water-based detector to select gammas from the cosmic ray fluxes, taking into account specific materials and their finishing; constraints in coincidence events, flight times, spatial and angular distributions and some specific properties of the produced light by the incidence of different primary sources. We concluded that we had detected the 2.22 MeV gamma ray emission line, considering the agreement between the results of the Monte Carlo simulation and those of the direct measurement in the laboratory with our original detector.