Plasma Physics
In a recent Letter [T. Dornheim \textit{et al.}, Phys. Rev. Lett. \textbf{121}, 255001 (2018)], it was predicted on the basis of \textit{ab initio} quantum Monte Carlo simulations that, in a uniform electron gas, the peak $\omega_0$ of the…
Plasma-based positron acceleration is still an open question, as the most efficient regimes for electron acceleration (quasi-linear and blowout) are not directly applicable to positrons. Nevertheless, positron acceleration is a stepping…
In this study, the first-of-its-kind use of active learning (AL) framework in thermal spray is adapted to improve the prediction accuracy of the in-flight particle characteristics and uses Gaussian Process (GP) ML model as a surrogate that…
Plasma acceleration is considered a prospective technology for building a compact multi-TeV electron-positron collider in the future. The challenge of this endeavor is greater for positrons than for the electrons because usually the…
We propose a new mechanism for generating coherent subcycle optical pulse by directing a relativistic electron beam (REB) into a plasma with a density up-ramp. The subcycle pulse is coherently emitted by bubble-sheath electrons in…
The development of machine learning techniques enables us to construct surrogate models from data of direct numerical simulations, which has important implications for modeling complex physical systems. In this paper, based on the output…
We examine dissipation and energy conversion in weakly collisional plasma turbulence, employing in situ observations from the Magnetospheric Multiscale (MMS) mission and kinetic Particle-in-Cell (PIC) simulations of proton-electron plasma.…
The role of a runaway current in a post disruption plasma is investigated through numerical simulations in an asymmetric magnetic reconnection event. While the runaways do not alter the linear growth of the island, they lead to a rotation…
We investigate the motion of charged particles in a turbulent electrostatic potential using guiding-center theory. By increasing the Larmor radius, the dynamics exhibit close-to-ballistic transport properties. The transition from diffusive…
A deep neural network is developed and trained on magnetic measurements (input) and EFIT poloidal magnetic flux (output) on the EAST tokamak. In optimizing the network architecture, we use automatic optimization in searching for the best…
Effects of resonant magnetic perturbations (RMPs) on tangential neutral beam heating in the EAST tokamak are studied numerically. RMPs with linear resistive magnetohydrodynamics response are used in the modeling. A variety of representing…
We present calculations of electrical resistivity for expanded boron, aluminum, titanium and copper plasmas using the Ziman formulation in the framework of the average-atom model. Our results are compared to experimental data, as well as…
Plasma-based CO2 conversion is a promising pathway towards greenhouse gas recycling. In the corresponding research field, various types of plasma reactors are applied for carbon dioxide dissociation. So far, spatial inhomogeneities of the…
Collisionless shock acceleration, which transfers localized particle energies to non-thermal energetic particles via electromagnetic potential, is ubiquitous in space plasma. We investigate dynamics of collisionless electrostatic shocks…
Simulations of high-density deuterium plasmas in a lower single-null magnetic configuration based on a TCV discharge are presented. We evolve the dynamics of three charged species (electrons, D$^{+}$ and D$_{2}^{+}$), interacting with two…
Collisionless and weakly collisional plasmas often exhibit non-thermal quasi-equilibria. Among these quasi-equilibria, distributions with power-law tails are ubiquitous. It is shown that the statistical-mechanical approach originally…
The paper investigates the feasibility of achieving uniform high-power volume heating for a fusion reactor concept employing a mixed fuel composition involving $\text{pBDT}$. The realm of mixed fuel fusion concepts remains relatively…
Consorzio RFX and INFN-LNL have designed, built and operated the compact radiofrequency negative ion source NIO1 (Negative Ion Optimization phase 1) with the aim of studying the production and acceleration of H- ions. In particular, NIO1…
This article presents an in-depth study of the sequence of events leading to density limit disruption in J-TEXT tokamak plasmas, with an emphasis on boudary turbulent transport and the high-field-side high-density (HFSHD) front. These…
The topology of the applied magnetic field is an important design aspect of Hall thrusters. For modern Hall thrusters, the field topology most often features curved lines with a concave (negative) curvature upstream of the field peak and a…