As the threat of climate change-caused destruction expands, humans have been looking to alternative energy sources for cleaner fuels. One source is nuclear fusion, which takes high temperatures and pressures to achieve, making it uneconomical. This has led to the research of muon-catalyzed fusion, which can happen at room temperature and has been proven to work.
How does fusion work?
Fusion occurs when two atoms get very close together, causing their nuclei to merge. This process takes a lot of heat and pressure to complete, since the nuclei need to hit each other with a lot of energy to fuse. However, the energy released during fusion can cause more atoms to fuse, leading to a self-sustaining chain reaction that powers stars. For example, when four hydrogen-1 atoms fuse to form helium-4, it releases 0.00000000000432 joules of energy. While that does not sound like a lot, about 10^38 of these reactions are happening every second, which amounts to 6.3 trillion “Little Boy” nuclear bombs being detonated every second!
What are muons?
Muons are an elementary particle, meaning that they are not composed of simpler elements. They are very heavy compared to electrons, and they decay after only 2.2 microseconds, about the time it takes for an airplane at cruising speed to travel 0.2 millimeters. However, they have many of the same properties of electrons.
Why are muons important?
The average atom consists of a nucleus of protons and neutrons surrounded by electrons*. Like electrons, muons can form atoms, but because of the muons’ weight, the atoms with muons will be much smaller, meaning that fusion can happen very easily.
Even though muons could be a source of limitless energy, there are still problems. Because of the muons’ short life, they are hard to collect. In addition, there is a chance that the muons themselves may be stuck in the helium atom that forms. Finally, the energy it takes to make the muons is currently more than what the muons can create, meaning that muon-catalyzed fusion is currently a net consumer of energy.
*Actually, the electrons exist in a “cloud of probability” dictated by the Schrödinger wavefunction. For our purposes, the electrons can be thought as “orbiting” the nucleus.