Nuclear fusion
Nuclear fusionNuclear Fusion is constantly present in our solar system. In the core of the sun, Hydrogen is converted to Helium providing enough energy to sustain life on earth. This process occurs at temperatures of 10-15 million degrees Celsius.
We are now trying different methods here on Earth to make fusion the next large-scale energy source. The most suitable reaction occurs between the nuclei of the two isotopes of Hydrogen - Deuterium (D) and Tritium (T). Scientist have already begun to test reactions involving just Deuterium or Deuterium and Helium (3He). (JSPF, Source 2)
The basic equation for D-T is Deuterium + Tritium ------ Helium-4 + neutron.
The amount of material fuel needed for fusion is rather low. For example 10 grams of Deuterium (which can be extracted from 500 liters of water) and 15g of Tritium (produced from 30g of Lithium) would produce enough fuel for the lifetime electricity needs of an average person in an industrialized country. (Environmental Organizations, Source 4)
The problems with fusion have been numerous. One of the problems is attaining the correct temperature for fusion to take place without using more energy then you produce. Fusion reactions occur at a sufficient rate only at very high temperatures. Over 100 million degrees Celsius is needed for the Deuterium-Tritium reaction, while other reactions require even higher temperatures. (Hotta Labs, Source 1)
The density of fuel ions must be sufficiently large for fusion reactions to take place at the required rate. The fusion power generated is reduced if the fuel is diluted by impurity atoms released from surrounding material surfaces or by the accumulation of Helium "ash" from the fusion reaction. As fuel ions are burnt in the fusion process they must be replaced by new fuel and the Helium ash must be removed. (U.S. Energy Science Program, Source 5)
To fuel nuclear fusion reactions, scientists heat a gas until its components dissociate (separate) in a process appropriately named dissociation. Once the gas's particles are separated into a mass of charged particles, ions, and electrons, plasma is formed. Plasma, characterized by very hot temperatures, is the actual fuel of fusion reactions as well as the fourth state of matter. Because plasma is commonly found floating in space or in stars, it is the most common state of matter. On earth, you can see plasma in flames, aurora, fluorescent lighting, neon signs, and lightning. (University of Illinois, Source 6)
Even with the hot plasma formed from heating gas until dissociation, fusion reactions aren't likely to occur because of the repulsion between similar or like charges. To overcome the repulsive force, more energy is added into the particles by heating the plasma to even greater temperatures. In order to get the plasma warm enough so...
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