Plasma Physics
Motivated by experiments employing ps-long, kilojoule laser pulses, we examined x-ray emission in a finite-length underdense plasma irradiated by such a pulse using two dimensional particle-in-cell simulations. We found that, in addition to…
This work investigates the electronic stopping power for protons of a tungsten plasma at various electron densities and temperatures. The study employs a dielectric formalism to model the stopping power due to free and bound electrons,…
A Hamiltonian two-field gyrofluid model is used to investigate the dynamics of an electron-ion collisionless plasma subject to a strong ambient magnetic field, within a spectral range extending from the magnetohydrodynamic (MHD) scales to…
A complete model for estimating the electric conductivity of combustion product gases, with added cesium (Cs) or potassium (K) vapor for ionization, is presented. Neutral carrier gases serve as the bulk fluid that carries the seed material,…
The dynamics of nonlinear ion-acoustic solitary waves in the presence of kinetic (Landau type) damping have been investigated in a collisionless, non-magnetized electron-ion plasma. A cold ion fluid model, coupled to a Vlasov-type kinetic…
We use analytical methods and particle-in-cell simulation to investigate the origin of electrons accelerated by the process of direct laser acceleration driven by high-power laser pulses in preformed narrow cylindrical plasma channels. The…
On the path towards high-gain inertial confinement fusion ignition, foams are being considered to tamp the hohlraum wall-motion, and mitigate laser backscattering from Stimulated Raman Scattering (SRS) and Stimulated Brillouin Scattering…
Relaxations of localized over-density in a plane transverse to the magnetic field are numericallyinvestigated under the effect of drift-wave and interchange drives in SOL conditions. Such a controlleddeparture from thermodynamic equilibrium…
The high confinement mode (H-mode), the most important operation mode for the nuclear fusion reactor, has been studied for 42 years, but the transition mechanism has not been unanimously agreed so far. Four decades of H-mode experiments…
We derive axisymmetric equilibrium equations in the context of the hybrid Vlasov model with kinetic ions and massless fluid electrons, assuming isothermal electrons and deformed Maxwellian distribution functions for the kinetic ions. The…
The Doppler backscattering (DBS) diagnostic, also referred to as Doppler reflectometry, measures turbulent density fluctuations of intermediate length scales. However, when the beam's wavevector is not properly aligned perpendicular to the…
Tokamaks and stellarators are the leading two magnetic confinement devices for producing fusion energy, begging the question of whether the strengths of the two could be merged into a single concept. To meet this challenge, we propose a…
Context. The mechanisms regulating the transport and energization of charged particles in space and astrophysical plasmas are still debated. Plasma turbulence is known to be a powerful particle accelerator. Large-scale structures, including…
Magnetic reconnection is a ubiquitous plasma process that transforms magnetic energy into particle energy during eruptive events throughout the universe. Reconnection not only converts energy during solar flares and geomagnetic substorms…
Since the DIII-D resonant magnetic perturbation experiment [Nucl. Fusion $\bm{59}$, 126010 (2019)] suggests that the neoclassical toroidal viscosity due to the collisional effects associated with the non-resonant magnetic perturbations is…
Recent study has demonstrated that electron cyclotron harmonic (ECH) waves can be excited by a low energy electron beam. Such waves propagate at moderately oblique wave normal angles (~70). The potential effects of beam-driven ECH waves on…
This work introduces the "potential vorticity bucket brigade," a mechanism for explaining the resilience of vortex structures in magnetically confined fusion plasmas and geophysical flows. Drawing parallels with zonal jet formation, we show…
A physics-informed neural network (PINN) is used to evaluate the fast ion distribution in the hot spot of an inertial confinement fusion target. The use of tailored input and output layers to the neural network is shown to enable a PINN to…
The paper presents ab initio results on the structural phase stability of beryllium and magnesium crystals under high and ultrahigh pressures (multi-terapascal regime). Magnesium is shown to undergo a number of structural transformations…
Positron creation and acceleration is one of the major challenges for constructing future lepton colliders. On the one hand, conventional technology can provide a solution, but at a prohibitive cost and scale. On the other hand,…