Magnetoacoustic shocks with geometrical effects in spin−12 dense plasmas.

The propagation characteristics of magnetoacoustic shock waves are investigated in an electron-ion dense magnetoplasma that accounts for spin − 1 2 electrons and geometrical effects within the framework of a two-fluid quantum magnetohydrodynamic model. For this purpose, we have employed the reductive perturbation technique and derived small-amplitude planar Korteweg de Vries Burgers (KdVB) and cylindrical KdVB equations. Numerically, cylindrical KdVB equations are analyzed by choosing the plasma parameters consistent with compact astrophysical systems. It is observed that the density, magnetic field, and viscosity are the parameters that ascertain significant modifications in the structure and propagation of magnetoacoustic shock waves. The amplitude of the shock wave becomes larger in the case of cylindrical geometry and propagates faster than that of planar shock waves. Furthermore, the results are compared with analytical solutions in the limit of earlier times to show an excellent agreement of the results. However, the magnetization energy is found to mitigate the amplitude of shock structures in a dense magnetoplasma where quantum spin effects cannot be ignored. [ABSTRACT FROM AUTHOR]