Confined hydrogenlike ions in plasma environments

Abstract

The behavior of H-like ions embedded in astrophysical plasmas in the form of dense, strongly and weakly coupled plasmas is investigated. In these, the increase and decrease in temperature are impacted by a change in confinement radius ${r}_{c}$. Two independent and generalized scaling ideas have been applied to modulate the effect of the plasma-screening constant $\ensuremath{\lambda}$ and ion charge $Z$ on such systems. Several relations are derived to interconnect the original Hamiltonian and two scaled Hamiltonians. In the exponential-cosine-screened Coulomb potential (ECSCP; dense) and weakly coupled plasma (WCP) these scaling relations have provided a linear equation connecting the critical screening constant ${\ensuremath{\lambda}}^{(c)}$ and $Z$. Their ratio offers a state-dependent constant beyond which a particular state vanishes. Shannon entropy has been employed to understand the plasma effect on the ion. With an increase in $\ensuremath{\lambda}$, the accumulation of opposite charge surrounding the ion increases, leading to a reduction in the number of bound states. However, with a rise in ionic charge $Z$, this effect can be delayed. The competing effect of plasma charge density ${n}_{e}$ and temperature in WCP and ECSCP is investigated. A recently proposed simple virial-like theorem was established for these systems. Multipole ($k=1--4$) oscillator strength and polarizabilities for these are studied considering $1s,2s$ states. As a bonus, analytical closed-form expressions are derived for ${f}^{(k)}$ and ${\ensuremath{\alpha}}^{(k)}(k=1--4)$ involving $1s$ and $2s$ states for the free H-like ion.

Topics & Concepts