Application of relativistic Fock-space coupled-cluster theory to study Li and Li-like ions in plasma

The ionization potentials, transition energies, and oscillator strengths of Li and Li-like C${}^{3+}$ and Al${}^{10+}$ are computed at different plasma environments with the Fock-space multireference coupled-cluster theory to examine the parametric dependence of these properties on plasma density and/or temperature. The results presented here show that the ionization and transition energies as well as the oscillator strengths are very sensitive to the plasma environment. It further shows that the spectral lines corresponding to $\Delta n=0$ transitions for Li-like C${}^{3+}$ and Al${}^{10+}$ are blueshifted, whereas the lines associated to $\Delta n\ne 0$ are redshifted ($n$ is the principal quantum number).

Figure 1

Variation of ionization potential with Debye screen-ing parameter $\mu$ (a.u.) for a Li atom. The inset plot is for the Al${}^{10+}$ ion.

Figure 2

Variation of excitation energies of a Li atom with Debye screening parameter $\mu$ (a.u.).

Figure 3

Variation of transition energies of Al${}^{10+}$ for a $\Delta n=0$ transition. The inset plot is for the $\Delta n\ne 0$ transition.

Figure 4

Effect of screening on various energy levels of Al${}^{10+}$.

Figure 5

Variation of oscillator strength with Debye screening parameter $\mu$. Panels (a) and (b) correspond to the $2p-2s$ and $3p-2s$ transitions of the Li atom, respectively. Panels (c) and (d) correspond to $2p-2s$ and $3p-2s$ transitions of the Al${}^{10+}$ ion, respectively.

Figure 6

Ionization potential of the Al${}^{10+}$ ion versus ion density in conjunction with the IS model.

Figure 7

Change in $2p$${}_{[1/2,3/2]}$-$2s$${}_{1/2}$ transition energies of Al${}^{10+}$ with ion density by invoking the IS model. The inset plot is for $3p$${}_{[1/2,3/2]}$-$2s$${}_{1/2}$ transition energies of Al${}^{10+}$ with ion density.