Plasma Physics
In this paper, we analyze the results of neutral-beam current drive (NBCD) experiments, performed in the TJ-II stellarator, with the aim of validating the theoretical predictions. Both parallel and anti-parallel injection with respect to…
A nonmodal kinetic theory of the stability of the two-dimensional compressed-sheared mesoscale plasma flows, generated by the radially inhomogeneous electrostatic ion cyclotron parametric microturbulence in the pedestal plasma with a…
It is well known that helical magnetohydrodynamic (MHD) turbulence exhibits an inverse transfer of magnetic energy from small to large scales, which is related to the approximate conservation of magnetic helicity. Recently, several…
In tokamak disruptions where the magnetic connection length becomes comparable to or even shorter than the plasma mean-free-path, parallel transport can dominate the energy loss and the thermal quench of the core plasma goes through four…
We present results from pulsed-power driven differentially rotating plasma experiments designed to simulate physics relevant to astrophysical disks and jets. In these experiments, angular momentum is injected by the ram pressure of the…
Equilibrium molecular dynamics simulations are performed to study two-dimensional (2D) dusty plasma liquids. Based on the stochastic thermal motion of simulated particles, the longitudinal and transverse phonon spectra are calculated, and…
Plasma-based acceleration has emerged as a promising candidate as an accelerator technology for a future linear collider or a next-generation light source. For a linear collider, the energy transfer efficiency from the drive beam to the…
In previous studies of spin-to-orbital angular momentum (AM) conversion in laser high harmonic generation (HHG) using a plasma target, one unit of spin AM is always converted into precisely one unit of OAM [1, 2]. Here we show, through…
A recently published, new analysis of current sheets updated the classic Harris 1D static solution by considering multiple classes of charged particle trajectories in a generalized dynamic current sheet. It used a 1D PIC simulation to…
I considered a four-component magnetized plasma medium consisting of opposite polarity ions and super-thermal distributed positrons and electrons to investigate the stable/unstable frequency regimes of modulated ion-acoustic waves (IAWs) in…
We extend the single-fluid solvability conditions to include plasma systems at arbitrary $\beta$ with arbitrary flows and external forcing terms. This treatment includes both the isotropic and the anisotropic cases. The generalized…
The nonlinear collisional dynamics of coupled driven plasma waves in the presence of background dissipation is studied analytically within kinetic theory. Sufficiently near marginal stability, phase space correlations are poorly preserved…
The STEP (Stability, Transport, Equilibrium, and Pedestal) integrated-modeling tool has been developed in OMFIT to predict stable, tokamak equilibria self-consistently with core-transport and pedestal calculations. STEP couples theory-based…
The proton-Boron 11 (p-B11) fusion reaction is much harder to harness for commercial power than the easiest fusion reaction, namely the deuterium and tritium (DT) reaction. The p-B11 reaction requires much higher temperatures, and, even at…
Alpha channeling uses waves to extract hot ash from a fusion plasma, while transferring energy from the ash to the wave. Intriguingly, it has been proposed that the extraction of this charged ash could create a radial electric field,…
In the classic Landau damping initial value problem, where a planar electrostatic wave transfers energy and momentum to resonant electrons, a recoil reaction occurs in the nonresonant particles to ensure momentum conservation. To explain…
When multiple species interact with an electrostatic ion acoustic wave, they can exchange momentum, despite the lack of momentum in the field itself. The resulting force on the electrons can have a curl, and thus give rise to compensating…
For an electrostatic wave interacting with a single species in a collisionless plasma, momentum conservation implies current conservation. However, when multiple species interact with the wave, they can exchange momentum, leading to current…
Recent diagnostic advances in gas-puff Z pinches at the Weizmann Institute for the first time allow the reconstruction of the current flow as a function of time and radius. These experiments show an unexpected radially-outward motion of the…
When a cylindrically-symmetric magnetized plasma compresses or expands, velocity-space anisotropy is naturally generated as a result of the different adiabatic conservation laws parallel and perpendicular to the magnetic field. When the…