Laser ablation and spectroscopy of copper in liquid and solid ~4He

摘要

We present an experimental study of the laser-induced fluorescence spectra of Cu atoms in bulk liquid andsolid helium matrices as well as in the dense plasma created by the laser ablation of copper in liquid helium.We observe transitions of the valence electron and of inner-shell electrons. The former produce structureless lineshapes, a large broadening, and a blueshift. The latter practically are not shifted with respect to the free atom andpossess a substructure consisting of a zero-phonon line and phonon wings. We suggest a qualitative interpretationof the observed spectra based on the atomic bubble model that takes the lifting of the |M_j| degeneracy due to thebubble deformation and matrix-phonon interactions into account.