Influence Of Screening Effect Of Hot And Dense Plasma On Atomic Properties

The influence of plasma environments on structures and processes of ions in hot and dense plasma is investigated utilizing a modified multi-configuration Dirac-Fork method by including the effect of the plasma screening. Approach based on the self-consistent-field multi-configuration Dirac-Fock model has been developed to study the screening effect on structures and transition properties of ions under different plasma conditions. Large amounts of atomic data for high ionization ions have been obtained, including energy levels, oscillator strengths and ionization energies, etc.Three models have been introduced in the present study, i.e., the Debye model, the ion sphere model and the self-consistent model. The three models are based upon the equivalent ensemble theory. The Debye model and the ion sphere model is well known and widely used for the calculation of the effect of the plasma screening, while the self-consistent model is a new approach for the investigation of the effect of plasmas screening by combining the ion sphere model, the average model and the multi-configuration Dirac-Fock method. A series of atomic data are calculated using the three models, and emphasis is placed on the changes of the transition energies, oscillator strengths and ionization energies of Beryllium-like medium-Z ions in hot and dense plasma where the range of ionized electron temperature and density are from 100eV to 2000eV and from 10²²cm^-3 to 10²⁴cm^-3, respectively.The results show that the atomic data are sensitive to the plasma density and temperature.The effect of plasma screening is found that the 2s²-[2s_1/2,2p_1/21 and 2s² -[2s_1/2,2p_3/2]₁ transition energies of beryllium-like ions increase with plasma density and temperature, leading to a blue-shift of this lines; the overall trend for the oscillator strengths of 2s² -[2s_1/2,2p_1/2]₁ and2s²-[2s_1/2, 2p_3/2]₁,transitions is similar; the first ionization energy of ions embedded in theplasma decreases, because of the influence of pressure ionization duo to the plasma screening. Moreover, the ionization energy decreases more and more quickly as the ionized electron density is increased or the ionized electron temperature is decreased.