Conveners
DPP-1 : Plasma Physics Symposium
- Lenaic Couedel (University of Saskatchewan)
Magnetic reconnection [1] is a physical non-ideal process involving conductive plasma flows. It converts magnetic energy into kinetic energy and heat by a topology modification of the magnetic field line. In presence of magnetic instabilities, the structures resulting from reconnection processes can then grow into “magnetic island(s)”.
In tokamaks, due to the high temperature required to...
The formation of soot particles in combustion, of cosmic dusts in the interstellar medium or of carbon nanoparticles in nonthermal plasmas, laser plumes, electric arcs or fusion devices is generally described by successive steps of nucleation, coagulation, processing and surface growth.
Nucleation is the crucial stage. Nevertheless, it is not well defined except in flames where polycyclic...
The amplification of cosmic magnetic fields by chaotic fluid motions is hampered by the adiabatic production of magnetic-field-aligned pressure anisotropy. This anisotropy drives a viscous stress parallel to the field that inhibits the plasma's ability to stretch magnetic-field lines. However, in high-$\beta$ plasmas, kinetic ion-Larmor scale instabilities---namely, firehose and mirror---sever...
The success of next-generation tokamaks such as ITER relies on minimizing the turbulent heat transport that limits confinement and on avoiding macroscopic instabilities that can lead to disruptions. Toroidal plasma rotation is known to be beneficial in both regards: It stabilizes the resistive wall mode and suppresses turbulence. Many current experiments induce rotation by applying an external...
to be posted later.
Plasma streamers produced by nanosecond discharges in dielectric media are known to be stochastic in nature. The dynamic of a streamer is highly sensitive to the electric field, among others. Streamer filamentation, produced by the communication of multiple streamers via electric fields and energetic photons, is always described as a stochastic phenomenon that depends on the propagation medium...
In this work, the non-equilibrium nature of argon-based radiofrequency (RF) and microwave plasmas at atmospheric pressure is evidenced. In particular, rotational temperature ($T_{rot}$) and neural gas temperature ($T_{g}$) are found to be unequal in every condition tested, even though they are often assumed equal in such plasmas in the literature. Such a finding was made possible through the...
to be posted later
For the first time, ultra-high-resolution optical absorption spectroscopy using a supercontinuum laser combined with a widely tunable filter and a hyperfine spectrometer is reported. The measurements were taken in a reduced pressure, nominally pure argon DC plasma. Such measurements allowed the determination of the number density of absorbing species (Ar 1s$_2$ and 1s$_4$ levels (Paschen...
Wood components made of cellulose, hemicellulose, lignin, extractives, etc. have been used as a building material for centuries. In light of the growing concern over the environmental impact of human industrial activity, wood has taken on a new importance worldwide. The main advantages of this widely-distributed and renewable resource lie in its versatility, strength-to-weight characteristics,...
Electron transport driven by instabilities is a universal feature in high- and low-temperature magnetized plasmas. Only fairly recently has it become feasible to simulate large-scale plasma transport within the framework of kinetic theory of gases and only the latest additions to computing power have enabled this to be done up to electron scales in tokamak plasmas and system size in...
The nonlinear evolution of the The Electron Cyclotron Drift Instability (ECDI)
driven by the electron EB drift in partially magnetized plasmas and anomalous
electron transport in two dimensions are studied using particle-in-cell (PIC) simula-
tions. PIC simulations were performed for the parameters typical of the Hall-e?ect
thruster in the two-dimensional azimuthal-radial geometry to...
Fusion reactors such as the tokamak, represent an attractive means of energy
production in terms of high power output, low emissions, few waste products and
safe operation. Unfortunately, multiple fundamental problems still need to be
addressed for a working reactor. The plasma wall interaction (PSI) is one of these crucial problems.
In a tokamak, a region known as the scrape off layer...
The acceleration of plasma in a magnetic nozzle has many important applications including nuclear fusion in magnetic mirrors, helicon thrusters for space propulsion and plasma based etching of semiconductors. The goal is to study the acceleration mechanism, determine what factors give rise to larger plasma acceleration and how plasma parameters such as density, pressure, electrostatic...
Plasma instabilities known as spokes have long been known to exist in ExB devices such as magnetrons and Hall Thrusters. The study of these spokes gives important insight into the ionization efficiencies and transport processes in these devices. However, spokes instabilities vary on small time scales, making characterization difficult. In this study we present results from the combined...
Materials under high intensity femtosecond laser irradiation yield extreme material conditions called warm dense matter (WDM) with thermal energy comparable with the Fermi energy and the ion-ion coupling parameter exceeding unity. The WDM state exists in a variety of processes ranging from laser micromachining to inertial confinement fusion experiments. The WDM exists as transient states...
It has only recently become possible to experimentally test our understanding of laser-plasma interaction processes in fusion scale plasmas relevant to directly-driven and indirectly-driven inertial confinement fusion. It is seen that seeded stimulated Brillouin scattering and Raman side-scatter are particularly important processes and pose significant constraints on allowable peak laser...
The diamond NV-centre is emerging as a candidate for high precision magnetic field
measurement. NV centres in diamond can be introduced in various ways. One
method is to dope the diamond film during the Microwave Plasma CVD growth
process. Production of thin diamond films doped with NV- centres has the potential
to be a key enabling technology for this advanced magnetic field sensing...
Pulsed electrical discharges in dielectric liquids are intensively studied due to the
wide range of applications in which they are implicated. Despite the simplicity of the experimental
manipulation of these discharges, the underlying fundamental physics is relatively complex. In this
study, we use the electrical characteristics, voltage and current, of pulsed discharges in water
(various...
to be posted later
Abstract
The nonlinear evolution of the The Electron Cyclotron Drift Instability (ECDI)
driven by the electron EB drift in partially magnetized plasmas and anomalous
electron transport in two dimensions are studied using particle-in-cell (PIC) simula-
tions. PIC simulations were performed for the parameters typical of the Hall-e?ect
thruster in the two-dimensional azimuthal-radial...
