Process of negative-muon-induced formation of an ionized acceptor center (μA)– in crystals with the diamond structure

The formation of an ionized acceptor center by a negative muon in crystals with the diamond structure is considered. The negative muon entering a target is captured by a nucleus, forming a muonic atom μ A coupled to a lattice. The appearing radiation-induced defect has a significant electric dipole moment because of the violation of the local symmetry of the lattice and changes the phonon spectrum of the crystal. The ionized acceptor center is formed owing to the capture of an electron interacting with the electric dipole moment of the defect and with the radiation of a deformation-induced local-mode phonon. Upper and lower bounds of the formation rate of the ionized acceptor center in diamond, silicon, and germanium crystals are estimated. It is shown that the kinetics of the formation of the acceptor center should be taken into account when processing μSR experimental data.