Yu. V. Arkhipov

Collective and static properties of model two-component plasmas.

Classical MD data on the charge-charge dynamic structure factor of two-component plasmas (TCP) modeled in Phys. Rev. A 23, 2041 (1981) are analyzed using the sum rules and other exact relations. The convergent power moments of the imaginary part of the model system dielectric function are expressed in terms of its partial static structure factors, which are computed by the method of hypernetted chains using the Deutsch effective potential. High-frequency asymptotic behavior of the dielectric function is specified to include the effects of inverse bremsstrahlung. The agreement with the MD data is improved, and important statistical characteristics of the model TCP, such as the probability to find both electron and ion at one point, are determined.

Direct Determination of Dynamic Properties of Coulomb and Yukawa Classical One-Component Plasmas

Dynamic characteristics of strongly coupled classical one-component Coulomb and Yukawa plasmas are obtained within the nonperturbative model-free moment approach without any data input from simulations so that the dynamic structure factor (DSF) satisfies the first three nonvanishing sum rules automatically. The DSF, dispersion, decay, sound speed, and other characteristics of the collective modes are determined using exclusively the static structure factor calculated from various theoretical approaches including the hypernetted chain approximation. A good quantitative agreement with molecular dynamics simulation data is achieved.

Stopping of relativistic projectiles in two-component plasmas

Relativistic and correlation contributions to the polarizational energy losses of heavy projectiles moving in dense two-component plasmas are analyzed within the method of moments that allows one to reconstruct the Lindhard loss function from its three independently known power frequency moments. The techniques employed result in a thorough separation of the relativistic and correlation corrections to the classical asymptotic form for the polarizational losses obtained by Bethe and Larkin. The above corrections are studied numerically at different values of plasma parameters to show that the relativistic contribution enhances only slightly the corresponding value of the stopping power.

Finite-size effects in the interaction of dust particles in a plasma

A pseudopotential model of interaction between dust particles is proposed to simultaneously take into account the nite-size and the screening effects. The consideration starts from the assumption that the dust particles are hard balls such that the interparticle distances are measured between their surfaces rather than between their centers. After that to derive the screened interaction potential between dust particles the density-response formalism is used in which the dielectric function of the plasma is taken in the form of the random-phase approximation. This procedure provides a simple analytic expression for the intergrain potential that numerically differs from the well-known Debye-Huckel (Yukawa) potential at small separations.

Effective potential and pressure of two-component plasma at high temperature

An effective pair interaction potential of particles for ideal and weakly non-ideal plasma were obtained. It takes into account not only screening and dynamic quantum effects, but also statistical quantum effects. Comparison between other kinds of potentials was conducted. The results for this potential show that our potential tends to a finite value at small distances and lies below Deutsch and Kelbg potentials. At large distances it tends to zero as Debye- Huckel potential. We used this potential for the calculation of plasma pressure and compared our results with simulation data. The calculated pressure values are in a good agreement with simulation one at high temperatures.