So why do we study plasmas? Because they are there of course! But also because the study of plasmas in general helps us understand a number of natural phenomena that we can see, and help us use plasmas for new technologies.
While traditional nuclear power plants use the heat from fission of uranium to produce electricity, a fusion power plant would fuse hydrogen atoms into helium produce energy. To achieve this, the hydrogen must be heated up to temperatures above 100,000,000 degrees Celsius! At these temperatures the hydrogen becomes a plasma, and can’t be held by normal materials. There is a rich community of scientists studying the physics of these sorts of hot, earthbound plasmas. Go to our Fusion Energy section to learn more.
Plasmas are an important part of many areas in astronomy and astrophysics. The interiors and outer atmospheres of stars, nebulae, and much of the hydrogen that exists between stars are all plasmas. Even more exotic astronomical bodies like white dwarfs consist of plasmas at some stages of their life. Pulsars and active galactic nuclei can create powerful jets of high energy plasmas. Closer to home in our own solar system, solar flares and the solar wind are plasmas that can give rise to complex plasma interactions with the magnetic fields of the planets. This solar weather can damage satellites and also leads to the Northern and Southern Lights.
M87 Active Galactic Nuclei Plasma Jet. Image Credit: hubblesite.org
Plasma Aided Manufacturing
Plasmas are often used in industry to alter the surface properties of components: either their chemistry or their structure. Plasma etching can be used in the fabrication of integrated circuits to introduce surface features to alter the behavior of the semi-conductor. Plasmas can also be used to deposit thin films of surfaces or to induce an oxidation layer to harden or to increase the corrosion resistance of a surface.
Image Credit: Solvay S.A.
For deep space missions, ion engines are used because of their high efficiency. By being able to accelerate the particles to much higher speeds than in a chemical rocket, less fuel can be used for the same amount of total acceleration. Ion thrusters have been used on the Dawn spacecraft as it studies the protoplanets Ceres and Vista. More advanced concepts like VASIMIR have been proposed to have higher powered thrusters than traditional ion thrusters, but with greater efficiency than traditional chemical rockets.
NASA Ion Thruster Experiment. Image Credit: JPL
Another situation in which plasmas occur on Earth is in the detonation of nuclear weapons. The US Department of Energy and National Nuclear Security Administration study these plasmas as part of their Stockpile Stewardship efforts. Scientists and engineers study how to ensure the safety and reliability of the American nuclear weapons stockpile using advanced modeling capabilities, and laboratory experiments while maintaining the Nation’s adherence to International treaties.