Energy is one of the most worrying problems in the world. There is a need to develop energy technology that is clean, sustainable and affordable to produce. Currently, more than 85% of energy is produced from fossil fuels, which will be exhausted within some time, presenting well-known disadvantages such as limited reserves and an increase in climate-damaging greenhouse gases. . Fusion is an alternative to all these types of energy sources, called “unlimited” and “sustainable”. The controlled fusion of atoms releases almost four million times more energy than a chemical reaction such as the combustion of coal, oil or gas and four times more than nuclear fission. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”? Get the original essay Fusion is a process that occurs inside stars and is a reaction in which two or more atomic nuclei come together enough to form one or more different ones. atomic nuclei and subatomic particles (neutrons or protons) overcoming the very high temperature Coulomb forces that exist at the heart of a star, such as the Sun (15 million 0C). It is a highly exothermic process releasing particles of much higher energy than fission and can produce self-sustaining reactions. The difference in mass between the colliding particles and the resulting nuclei manifests itself in the release of a large amount of energy, which is materialized by the contrast in binding energy between the nuclei before and after the reaction. This is exactly expressed by Einstein's famous formula; where the mass lost in reaction is m and c being the speed of light. Some interesting fusion reactions are given below, and the most accessible is that involving deuterium and tritium, the two isotopes of hydrogen. Everything in the universe begins with a big bang, just like fusion. The nuclear fusion process in stars is limited to elements lower than iron because it subtracts energy rather than providing it, as it is one of the most tightly bound nuclei. Thus, a prerequisite for the fusion reaction is that the colliding nuclei are lighter than iron-56 or nickel-62, because these elements have the smallest mass per nucleon and the greatest binding energy per nucleon, respectively creating an exothermic reaction. These fusions of these light elements release energy (an exothermic process), while a fusion producing nuclei heavier than these elements will result in energy retention by the resulting nucleons, and the resulting reaction is endothermic. Reversibly, nuclei heavier than Fe-56 require an external energy source for the reaction to occur. Thus, lighter elements like hydrogen, deuterium and helium have a higher probability of fusion than those of elements heavier than Fe-56 like uranium and plutonium, which are more likely to break up , which means fission. Only extreme cosmic events from interstellar entities can produce enough energy to fuse nuclei into elements heavier than iron..