Spectroscopy of Confined Atomic Systems: Effect of Plasma

Abstract

The effect of spatial and other external confinements on the ground and excited state energy levels of many electron atoms, ions and exotic systems is discussed. Special emphasis is given to analyzing and estimating the changes in the spectral properties of plasma embedded systems in which, apart from changes in the free particle potential due to atom plasma interaction, spatial confinement enters through the introduction of boundary conditions. Effects of weak as well as strong plasma on the dipole polarizabilities, ionization potentials, singly and doubly excited state energy levels, oscillator strengths and transition probabilities have been discussed using simple plasma models but adopting rigorous quantum chemical methods. The spectral line shifts under strongly coupled plasma have been compared with data available from laser plasma experiments. Specific attention has been given to extremely accurate estimates of the energies of different three-body systems under plasma environments. The importance of the use of finite boundary conditions originating from spatial confinement of the plasma has been demonstrated and the effect of electron correlation in estimating various confined atomic properties is shown. Attempt has been made to interpret the changes in the spectral properties of atoms trapped in cavities inside liquid helium environments, by comparing the results estimated on the basis of current quantum chemical methodologies with the data available from laser induced fluorescence experiments.