Research for tomorrow's energy supply
Image NASA Goddard Space Flight Center [CC BY 2.0], via Wikimedia Commons
What is Fusion?
Nuclei of lighter atoms such as hydrogen collide and fuse together to produce nuclei of heavier atoms such as helium and release vast amounts of energy in the process —this is the essence of fusion. Because the energy is derived from the action of nuclei, fusion is a form of nuclear energy. It maybe considered the opposite of fission, also a form of nuclear energy, which is generated when nuclei of heavy atoms into split into lighter ones. Fusion is the process that powers and drives the production of energy in stars, such as our Sun.
On the Sun, four protons are converted into one helium nucleus. Energy is released because the helium nucleus has slightly less mass than the original four protons.
The Earth does not have the immense gravitational force required to confine the hydrogen nuclei. So a different approach is needed to achieve fusion reactions on Earth.
Fuel: The most efficient fusion fuel is a mixture of deuterium and tritium; Temperature: between 100 and 200 million degrees Celsius; Density: approximately 1 milligram per meter-cubed;Time: maintain these conditions for as long as possible!
It seems confusing that energy can be generated by both fusion (the coalescence of two nuclei) and fission (splitting the nucleus), as they appear to be quite opposite processes. The explanation lies in the size of the nuclei. Learn more.
Some 70 years ago scientists obtained the first insights into the physics of sunshine: when the sun and other stars transmute matter, tirelessly transforming hydrogen into helium by the process of fusion, they release colossal amounts of energy.
