The Muon Drive was an early Hemmoian type B sub-light propulsion system, employing a muon-catalyzed fusion reaction. It was first used by the Vonoskela, a deep space research vessel.
The Mark V represented the culmination of the Muon Drive technology.
Muon-catalyzed fusion (μCF) is a process allowing nuclear fusion to take place at temperatures significantly lower than the temperatures required for thermonuclear fusion. Muons are unstable subatomic particles similar to electrons, but about 207 times more massive.
If a muon replaces one of the electrons in a hydrogen molecule, the nuclei are consequently drawn 196 times closer than in a normal molecule, due to the reduced mass being 196 times the mass of an electron. When the nuclei are this close together, the probability of nuclear fusion is greatly increased, to the point where a significant number of fusion events can happen at low temperature.
To create useful low temperature muon-catalyzed fusion, reactors need a cheap, efficient muon source and/or a way for each individual muon to catalyze many more fusion reactions.
One muon source is the anti-proton, which produces pions in the annihilation process with a proton. Upon decay, pions give rise to the muons needed to catalyze DT fusion reactions, and prior to their decay they can contribute to additional fusion reactions through the plasma heating they provide.
The number of muon-catalyzed fusions (MCFs) per one muon also increases dramatically in a compressed target. Furthermore, MCFs deposited on to very small regions in a compressed DT target can initiate high-temperature inertial fusion with a smaller amount of energy than conventional inertial fusion.