Quantum statistical approach for ionization potential depression in multi-component dense plasmas

Abstract

Theoretical modeling of ionization potential depression (IPD) and the related ionization equilibrium in dense plasmas, in particular, in warm/hot dense matter, represents a significant challenge due to ionic coupling and electronic degeneracy effects. Based on the dynamical structure factor (SF), a quantum statistical model for IPD in multi-ionic plasmas is developed, where quantum exchange and dynamical correlation effects in plasma environments are consistently and systematically taken into account in terms of the concept of self-energy. Calculations for IPD values of different chemical elements are performed with the electronic and ionic SFs. The ionic SFs are determined by solving the Ornstein–Zernike equation in combination with the hypernetted-chain closure relation. As a further application of our approach, we present results for the charge state distribution of aluminum plasmas at several temperatures and densities through solving the coupled Saha equations.

Investigating Mechanisms of State Localization in Highly-Ionized Dense Plasmas

“…This rich collection of experimentally observed discrepancies has spurred a flurry of theoretical investigations into how best to model, predict, and understand, the effect of IPD. Efforts have been made using ion-sphere models [25][26][27]; Hartree-Fock-Slater calculations [28]; models based on plasma theory [18,29,30]; classical molecular dynamic simulations [31]; quantum statistical models [32,33]; Monte Carlo methods [34]; and density functional theory calculations with and without molecular dynamics [35][36][37]. Unfortunately, no consistent agreement has emerged between all these methods, but the majority of them do predict, as does the experimental data, that the IPD should lie energetically somewhere between the predictions of the SP and EK models.…”

Ionization by electron impacts and ionization potential depression

“…These two main experiments have stimulated many theoretical investigations of IPD (see for instance Refs. [15][16][17][18]), in particular using Density Functional Theory.…”

“…On the other hand, in an experiment performed at the Orion laser system (UK) [14], with a plasma at higher temperatures [500-700] eV and densities in the range [1][2][3][4][5][6][7][8][9][10] g cm −3 , the aluminum K-shell spectrum shows a better agreement with cal-culations if one uses the Stewart-Pyatt IPD rather than the Ecker-Kröll one. These two main experiments have stimulated many theoretical investigations of IPD (see for instance references [15][16][17][18]), in particular using density functional theory.…”

Multi-Configuration Calculation of Ionization Potential Depression

“…Their experimental and theoretical studies have aroused the interest of scientists for many years, either for accurate determination [1] or looking for regularities along isoelectronic sequences [2], etc. Ionization potential depression (IPD) or continuum lowering in dense plasmas has been the subject of many investigations over the past years [3][4][5][6]. This many-body effect significantly alters the ionization balance and the corresponding charge state distribution, which have a strong influence on thermodynamic [7], transport [8][9][10] and radiative properties of the system [11,12].…”