Answer: Recombination of two Helium-3 into one nucleus of Helium.
Explanation: Hydrogen fusion is the process of connecting the protons from the four nuclei of Hydrogen, whereby the reaction of the coupling of these protons obtains the Helium nuclei. As a result of this reaction, also two neutrons and six photons are obtained with a large amount of energy. Fusion of Hydrogen takes place in three steps. The first step is the fusion of Hydrogen in Deuterium, the second step is the formation of Helium-3, while the third step is the recombination of two Helium-3 into one Helium nuclei.
