Perturbative approach to the self-focusing of intense X-ray laser beam propagating in thermal quantum plasma

Abstract

In this theoretical study, the problem of self-focusing of an X-ray intense laser beam in the thermal quantum plasma is studied. Using a relativistic fluid model and taking into account the hydrodynamic pressure of degenerate electrons in the zero temperature limit, the nonlinear momentum equation of electrons is solved by means of a perturbative method and the nonlinear current density of the relativistic degenerate electrons is obtained. Saving only the third-order nonlinearity of the laser beam amplitude, a nonlinear equation describing the interaction of a laser beam with the quantum plasma is derived. It is shown that considering the nonlinearity of the system through solving the nonlinear equation of the degenerate electron leads to the originally different wave equation in comparison to outcomes of the approach in which the permittivity of longitudinal waves of quantum plasma is problematically extended to the relativistic case. The evolution of the laser beam spot size with the Gaussian profile is considered, and the effect of quantum terms on the self-focusing quality is studied. It is shown that considering quantum effects leads to the decrease in the self-focusing property and the effect of Bohm tunneling potential is more dominant than the degenerate electron pressure term.

Self-focusing of linearly-polarized laser beam in the semi-bounded magnetized warm plasma: competition of right- and left-hand circularly-polarized modes

“…It should be mentioned that the continuity equation used here is fully relativistic, and precisely obtained from reference material [70][71][72][73]. However, surprisingly, in most previous works (cf [49,53]), a non-relativistic continuity equation is used, and from this point of view the non-linear current density value obtained below can be inferred to be the more accurate method of describing the non-linear interaction of lasers with relativistic magnetized hot plasma.…”

“…Ponderomotive [45], thermal [46], and relativistic [47] mechanisms can individually lead to the SF of an intense laser beam in plasma. Nonlinear propagation of a laser beam in unbounded plasma, taking into account the SF phenomenon during its propagation, has been theoretically investigated in many articles (see [32,[45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] to give just a few examples).…”

“…The non-linear equations are obtained based on the fully relativistic momentum and continuity equations. To date, as our literature search shows, in the study of SF in plasma for the relativistic regime, only the fluid momentum equation is modified, by considering the Lorentz relativistic factor in the inertia term, and this modification is absent for the continuity equation [50,53,[64][65][66][67], which can clearly be considered as an incomplete relativistic model. Here, we use fully relativistic fluid equations in their proper forms, based on reference [68], and take into account the non-linear response of the magnetized warm plasma.…”

Laser beam effect on the entanglement of elastic collisions in quantum plasma

“…The inter-particle interaction potential for dressed electron-ion scattering in hot quantum plasmas [51] as well as in dense quantum plasmas with different initial conditions has been investigated [52][53][54]. Quantum mechanical effects based on the definition of effective potential functions are widely investigated in dense plasmas that appear in the core of giant planets [55], high energy laser-solid plasma interaction [56][57][58][59][60], ion accelerators [61], compact astrophysical objects and cosmological environments [62,63], the construction of ultra-small electronic devices [64], metal nanostructures [65] and many other subjects.…”

Entanglement fidelity ratio for elastic collisions in non-ideal two-temperature dense plasma

“…Therefore, it is better to consider wave aspect for the colliding particles taking into account some quantum-mechanical effects such as diffraction and symmetry [24][25][26]. Such quantum mechanical aspect of plasma has the vast applications in various fields including intense laser-solid density plasma interaction [27][28][29][30][31], ion accelerator [32], dense plasmas appeared in the core of planets [33], astrophysical and cosmological environments like white dwarf stars [34,35], so-called ultra-small electronic devices [36] and metal nanostructures [37].…”