We present an exhaustive overview of optical absorption and laser-induced fluorescence lines of Ba atoms in liquid and solid helium matrices in visible and near-infrared spectral ranges. Due to the increased density of isolated atoms, we have found a large number of spectral lines that were not observed in condensed helium matrices before. We have also measured the lifetimes of metastable states. The lowest ${}^{3}{D}_{1}$ metastable state has lifetime of 2.6 s and can be used as an intermediate state in two-step excitations of high-lying states. Various matrix-induced radiationless population transfer channels have been identified.We present an exhaustive overview of optical absorption and laser-induced fluorescence lines of Ba atoms in liquid and solid helium matrices in visible and near-infrared spectral ranges. Due to the increased density of isolated atoms, we have found a large number of spectral lines that were not observed in condensed helium matrices before. We have also measured the lifetimes of metastable states. The lowest ${}^{3}{D}_{1}$ metastable state has lifetime of 2.6 s and can be used as an intermediate state in two-step excitations of high-lying states. Various matrix-induced radiationless population transfer channels have been identified.

Physical Review AAug 3, 201114 citations

{}^{3}{D}_{1}

metastable state has lifetime of 2.6 s and can be used as an intermediate state in two-step excitations of high-lying states. Various matrix-induced radiationless population transfer channels have been identified.