Oxford Centre for High Energy Density Science (OxCHEDS)

Abstract:

We extend the classical magnetohydrodynamics formalism to include nonlocal quantum behavior via the phenomenological Bohm potential. We then solve the quantum magnetohydrodynamics equations to obtain a new analytical form of the dynamic structure factor (DSF), a fundamental quantity linking theory and experiments. Our results show that the three-peak structure—one central Rayleigh peak and two Brillouin peaks—of the DSF arising from quantum hydrodynamic fluctuations becomes (in general) a five-peak structure—one central Rayleigh peak and two pairs of peaks associated with fast and slow magnetosonic waves. The Bohm contribution influences the positions and characteristics (height, width, and intensity) of the peaks by introducing three significant modifications: (a) an increase in effective thermal pressure, (b) a reduction in the adiabatic index, and (c) an enhancement of effective thermal diffusivity. The multiple DSF peaks enable concurrent measurements of diverse plasma properties, transport coefficients, and thermodynamic parameters in magnetized dense plasmas. The potential for experimental validation of our theory looms large, particularly through future experiments conducted at state-of-the-art laser facilities.

Abstract:

The Author takes into consideration the imperial comites epigraphically attested, and who participated in the military campaigns of L. Verus, L. Verus and M. Aurelius, M. Aurelius alone, and M. Aurelius with Commodus (161-180), comparing their careers. These comites Augusti were selected from among the senators deemed most suitable for fulfilling this highly significant role. The key requirements seem to have been a close connection to the imperial household, but also military abilities, since they had to fight alongside the emperor. Some of them had already fought along the Roman frontiers and belonged to that small circle of viri militares.