Nuclear Fusion (Cambridge (CIE) IGCSE Physics): Revision Note

Nuclear fusion

Extended Tier Only

• The Sun releases energy by the process of nuclear fusion in its core

  • Nuclear fusion is the process where two light atomic nuclei join together to create a heavier nucleus, releasing massive amounts of energy in the process

  • In the Sun, hydrogen nuclei fuse together to form helium nuclei

• It is theoretically possible to produce a fusion reactor that could be used to generate electricity

  • If this technology can be made to work at scale, it could supply very large amounts of electricity without producing carbon dioxide

• Fusion requires extremely high temperatures and high pressures, like in the centre of a star

  • This is to overcome the repulsive forces between nuclei

• Scientists are currently researching how to sustain a fusion reaction at lower temperatures

  • International research projects, funded mainly by governments working together, are making progress with some promising results

• Experiments have now released more energy from the fusion reaction than was delivered to the fuel, but not yet more than the total energy required to run the whole facility

  • Producing a sustained net energy gain remains the goal

  • If they succeed, virtually limitless amounts of energy could be produced, with large-scale, carbon-free electricity generation