Muon capture is the capture of a negative muon by a

proton A proton is a stable subatomic particle, symbol , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an e ...

, usually resulting in production of a

neutron The neutron is a subatomic particle, symbol or , that has no electric charge, and a mass slightly greater than that of a proton. The Discovery of the neutron, neutron was discovered by James Chadwick in 1932, leading to the discovery of nucle ...

and a neutrino, and sometimes a

gamma Gamma (; uppercase , lowercase ; ) is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter normally repr ...

photon A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless particles that can ...

. Muon capture by heavy nuclei often leads to emission of particles; most often

s, but charged particles can be emitted as well. Ordinary muon capture (OMC) involves capture of a negative muon from the atomic orbital without emission of a gamma photon: : + → _μ + Radiative muon capture (RMC) is a radiative version of OMC, where a gamma photon is emitted: : + → _μ + + Theoretical motivation for the study of muon capture on the proton is its connection to the proton's induced pseudoscalar form factor g_p.

Practical application - Nuclear waste disposal

Muon capture is being investigated for practical application in radioactive waste disposal, for example in the artificial transmutation of large quantities of long-lived

radioactive waste Radioactive waste is a type of hazardous waste that contains radioactive material. It is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, nuclear decommissioning, rare-earth mining, and nuclear ...

that have been produced globally by fission reactors. Radioactive waste can be transmuted to stable isotopes following irradiation by an incident muon () beam from a compact proton accelerator source.

References

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Nagamine, Kanetada (2016) "Nuclear Waste Disposal Method and its apparatus using muon-nuclear-absorption". (WO2016143144A1)
Espacenet (Patent database). Nuclear physics {{particle-stub