Muon catalysed fusion. Chemical confinement of nuclei within the muonic molecule dtμ

Negative muons may be used as a catalyst to fuse hydrogen nuclei into helium. The necessary confinement of nuclei is obtained on a microscopic scale by chemical bonding within ''exotic'' muonic molecules such as dtμ, without the extreme physical conditions required for macroscopic plasma confinement in Tokamaks and laser reactors. Fusion energy released by muon catalysis exceeds the rest-mass energy of participating muons, which triggered questions about suitability of this process for energy production. The present article reviews the theoretical studies of the microscopic events constituting the fusion chain. The aim of these studies is to optimize the fusion yield by understanding its dependence on the macroscopic conditions such as temperature, fuel density and/or composition. Apart from the energy production aspects, the field of muon catalysed fusion (μCF) is also a wonderful example of interdisciplinary basic research combining exotic chemistry with atomic, nuclear, and particle physics. While the μCF reactions occur for all hydrogen isotopes, the present review emphasizes the theoretical and experimental results obtained for the case of dtμ. (Author)