Non-linear charge reduction effect in strongly-coupled plasmas

The charge reduction effect, produced by the nonlinear Debye screening of high-Z charges occuring in strongly-coupled plasmas, is investigated. An analytic asymptotic expression is obtained for the charge reduction factor which determines the Debye-Hueckel potential generated by a charged test particle. Its relevant parametric dependencies are analyzed and shown to predict a strong charge reduction effect in strongly-coupled plasmas.Comment: 4 figure

On the Internal Structure of Relativistic Jets

A magnetohydrodynamic model is constructed for a cylindrical jet immersed in an external uniform magnetic field. It is shown that, as in the force-free case, the total electric current within the jet can be zero. The particle energetics and the magnetic field structure are determined in a self-consistent way; all jet parameters depend on the physical conditions in the external medium. In particular, we show that a region with subsonic flow can exist in the central jet regions. In actual relativistic jets, most of the energy is transferred by the electromagnetic field only when the magnetization parameter is sufficiently large, $\sigma>10^6$. We also show that, in general, the well-known solution with a central core, $B_z = B_0/(1+\varpi^2/\varpi_c^2)$, can not be realized in the presence of an external medium.Comment: 19 pages, 2 figure

Ionospheric gas dynamics of satellites and diagnostic probes

The gas dynamics of interactions of a tenuous ionosphere with moving satellites and probes that have bearings on the diagnostics of the ionosphere are discussed. Emphasis is on the cases where the body is moving at mesothermal speeds, namely intermediate between the thermal speeds of ions and electrons of the ambient ionosphere. Methods of collision-free plasma kinetics with self-consistent field are used. The development of the topics for discussion starts with stationary Langmuir probe which entails the basic mechanism of body-plasma interaction that becomes further intricated as the body moves at a higher and higher speed. Applications of the theory of plasma interaction to meteors which move in the ionosphere are also presented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43801/1/11214_2004_Article_BF00212707.pd