等离子体物理
Stellarator optimization often takes a two-stage approach, where in the first stage the boundary is varied in order to optimize for some physics metrics, while in the second stage the boundary is kept fixed and coils are sought to generate…
We consider a magnetised plasma in contact with an absorbing planar wall, where the angle $\alpha$ between the magnetic field and the wall is small, $\alpha \ll 1$ (in radians) and the system is symmetric tangential to the wall. The finite…
In this study, we develop an extended implicit moment method, namely, a coupled high-order low-order (HOLO) method and apply it to the electromagnetic Vlasov-Darwin model. The high-order (HO) system evolves particles in a manner that…
Mercier's criterion is typically enforced as a hard operational limit in stellarator design. At the same time, past experimental and numerical studies have shown that this limit may often be surpassed, though the exact mechanism behind this…
Magnetic geometry has a significant effect on the level of turbulent transport in fusion plasmas. Here, we model and analyze this dependence using multiple machine learning methods and a dataset of > 200,000 nonlinear simulations of…
Kinetic models provide highly accurate descriptions of plasma waves but involve complex integrals that are computationally expensive to solve. To facilitate a fluid-like treatment of the system, we propose rational approximations for both…
The Polywell fusion concept, originally proposed by Robert W. Bussard in 1985, has been investigated for over four decades as a potential solution for achieving net fusion energy in a compact and economically viable reactor. It combines two…
A simple model of the ramp-up and ramp-down of the toroidal current in a tokamak plasma is developed. Faraday's law of electric induction is found to limit how rapidly the current can be safety ramped up or down. It is estimated that the…
Coupling a high-performance burning plasma core to a detached boundary solution is critical for realizing magnetic confinement fusion power. Predictive simulations of the edge and scrape-off layer are therefore essential and must…
Probing the neutral gas distribution at the edge of magnetic confinement fusion devices is critical for plasma exhaust studies. In the TCV tokamak, a set of ASDEX-type hot ionization pressure gauges (APGs) has been installed for fast,…
Plasma edge simulations with the SOLPS-ITER code are performed to study the influence of divertor baffles on nitrogen-seeded detachment in TCV single-null, L-mode discharges. Scans of nitrogen seeding rate are conducted in both baffled and…
We present the first gyrokinetic simulations of multiscale turbulence in a stellarator, using the magnetic geometry of Wendelstein 7-X (W7-X) and experimentally relevant parameters. A broad range of scenarios is explored, including regimes…
The interaction of an ultraintense Nd:glass laser pulse with a near-critical plasma self-organizes into a highly efficient $\gamma$-ray source. Three-dimensional particle-in-cell simulations demonstrate that relativistic self-focusing,…
Electron transpiration cooling (ETC) offers a promising approach for thermal management of hypersonic vehicles by leveraging thermionic emission from the leading edge. While emitted electrons cool the surface, subsequent collection of…
Refraction of an optical probe beam by a plasma can be measured with angular filter refractometry (AFR), which produces an image containing intensity contours that correspond to curves of constant refraction angle. Further analysis is…
In this review, we examine particle transport in strongly turbulent three-dimensional (3D) magnetized plasmas, characterized by intense (large-amplitude) magnetic field fluctuations. Such environments naturally give rise to a network of…
A linearized Vlasov-Poisson system of equations is transformed into a Schr\"{o}dinger equation, which is used to demonstrate that the fluctuation theorem holds for the relative stochastic entropy, defined in terms of the probability density…
The effect of magnetic shear on ballooning-driven plasma edge turbulence is studied through nonlinear simulations complemented by linear numerical and analytical investigations. Nonlinear, 3D, global, flux-driven simulations using the GBS…
This paper presents a novel magnetohydrodynamics (MHD) system for planetary entry aerocapture. The system is advantaged over previous approaches by having the following two characteristics: (i) it can be deployed locally to one or various…
The Vlasov-Maxwell equations provide kinetic simulations of collisionless plasmas, but numerically solving them on classical computers is often impractical. This is due to the computational resource constraints imposed by the time evolution…