Effect of Debye plasma on the structural properties of compressed positronium atom

The effect of weakly coupled plasma on the energy levels and other structural properties of compressed positronium atom has been analysed. The positronium atom is treated as a quasistable system and the compression is obtained by embedding the atom at the centre of an impenetrable spherical box. The dipole polarizabilities, transition energies, oscillator strengths and transition probabilities of a few low lying allowed excited states have been obtained for various plasma strengths with different confinement radii. (C) 2002 Elsevier Science B.V. All rights reserved.