Article

# Addendum to "Equation of state of classical Coulomb plasma mixtures".

Ioffe Physical-Technical Institute, St. Petersburg, Russia.

Physical Review E (Impact Factor: 2.31). 10/2009; 80(4 Pt 2):047401. DOI: 10.1103/PHYSREVE.80.047401 Source: PubMed

- [Show abstract] [Hide abstract]

**ABSTRACT:**We analyze enhancement of thermonuclear fusion reactions due to strong plasma screening in dense matter using a simple electron drop model. The model assumes fusion in a potential that is screened by an effective electron cloud around colliding nuclei (extended Salpeter ion-sphere model). We calculate the mean field screened Coulomb potentials for atomic nuclei with equal and nonequal charges, appropriate astrophysical S factors, and enhancement factors of reaction rates. As a byproduct, we study analytic behavior of the screening potential at small separations between the reactants. In this model, astrophysical S factors depend not only on nuclear physics but on plasma screening as well. The enhancement factors are in good agreement with calculations by other methods. This allows us to formulate the combined, pure analytic model of strong plasma screening in thermonuclear reactions. The results can be useful for simulating nuclear burning in white dwarfs and neutron stars.Physical Review C 01/2014; 89(1). · 3.88 Impact Factor - [Show abstract] [Hide abstract]

**ABSTRACT:**It is shown that the Coulomb energy U of fully ionized ionic mixture can be written as a sum over partial contributions of ion species j: U = T ΣjNju (Γj, yj) (generalized linear mixing rule). In contrast to the traditional linear mixing rule ULM = T ΣjNjuOCP(Γj), applicable for strong coupling, the partial contribution function u depends not only on Γj, but on an additional parameter yj = (rD/rDOCP)2 also. Here rD and rDOCP are Debye radiuses in the mixture and in the one component plasma at coupling parameter Γj, correspondingly. The parameter yj does not depend on a specific composition of the mixture, but on the Debye radius rD only, making function u (Γj, yj) universal. The generalized linear mixing rule can be applied at any coupling parameter, if ionic mixture is not crystallized. It reproduces results of the Debye-Hückel theory at weak coupling and traditional linear mixing rule at strong coupling. It can be easily applied to the complicated mixtures, composed of a large number of ion species. Since yj is temperature independent, the Coulomb contribution to Helmholtz free energy of the mixture can also be presented in a form of generalized linear mixing rule (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)Contributions to Plasma Physics 02/2012; 52(2):114-117. · 0.98 Impact Factor - [Show abstract] [Hide abstract]

**ABSTRACT:**The liquid-solid phase-diagram of dense carbon-oxygen plasma mixtures found in white dwarf stars interiors is determined from molecular dynamics (MD) simulations. Our MD simulations consist of boxes with 55296 ions with different carbon to oxygen ratios. Finite size effects are estimated comparing the new MD simulations results to previous smaller simulations. We use bond angle metric to identify whether an ion is in the solid, liquid or interface and study non-equilibrium effects by obtaining the diffusion coefficients in the different phases. Our phase diagram agrees with predictions from Medin and Cumming obtained by an independent method.Journal of Physics Conference Series 12/2012; 402(1):2026-.

Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.