The impact of Hall physics on magnetized high energy density plasma jets

Abstract

Hall physics is often neglected in high energy density plasma jets due to the relatively high electron density of such jets (ne ∼ 1019 cm−3). However, the vacuum region surrounding the jet has much lower densities and is dominated by Hall electric field. This electric field redirects plasma flows towards or away from the axis, depending on the radial current direction. A resulting change in the jet density has been observed experimentally. Furthermore, if an axial field is applied on the jet, the Hall effect is enhanced and ignoring it leads to serious discrepancies between experimental results and numerical simulations. By combining high currents (∼1 MA) and magnetic field helicity (15° angle) in a pulsed power generator such as COBRA, plasma jets can be magnetized with a 10 T axial field. The resulting field enhances the impact of the Hall effect by altering the density profile of current-free plasma jets and the stability of current-carrying plasma jets (e.g., Z-pinches).

Polytropic representation of the kinetic pressure tensor of non-ideal magnetized fluids in equilibrium toroidal structures

“…to be denoted as tetrad representation, where (u 0 , u 1 , u 2 , u 3 ) are the corresponding components and are separately 4−scalars. Then, we recall that for single-particle dynamics the 4−dimensional velocity space V 4 is defined as the tangent bundle of the configuration-space manifold R 4 whose 4−vectors are subject to the mass-shell constraint (5). Thus, the unconstrained 8-dimensional phase-space Ω is defined as Ω = R 4 × V 4 .…”

“…so that the time-component of the 4−velocity depends on the squared space-components. Notice that this equation is related to the mass-shell condition (5).…”

“…A relevant theoretical issue in statistical physics concerns the mathematical description of the complex phenomenology that characterizes microscopic as well as continuum fluid dynamics of magnetized plasmas at equilibrium and which exhibit properly-defined symmetric geometric structures. Applications include in particular astrophysical scenarios represented by relativistic jets associated with compact objects, binary compact object mergers and gamma-ray bursts [1][2][3][4] as well as the physics of complex non-linear magnetized plasmas in the framework of soft-matter studies [5][6][7][8]. For these systems, both single-particle and macroscopic fluid velocities of the plasma can become relativistic, i.e., comparable with the speed of light c when measured in a defined reference frame (e.g., the laboratory or fluid comoving frames).…”