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Transient plasma in atmospheric pressure fuel-air mixtures, that is, plasma during a formative, short time period prior to equilibration of the plasma electron energy distribution, is studied for applications to the fundamental improvement of fuel-burning engine efficiency. Transient plasma has been demonstrated to substantially reduce ignition delay, and shows promise for improving engine efficiency...
A kinetic model of the ignition of explosive electron emission center ecton1,2 on the cathode by the action plasma surface interaction was developed. The model describes the metal microprotrusion (curvature radius 1 micrometer) heating by both plasma metal interaction and joule heating. The model describes the evaporation from the metal surface and correspondent secondary plasma generation. The secondary...
A final pulse of hot electrons can induce preheat and shock ignition[su1} under direct drive, as recently demonstrated2 with the implicit/hybrid code ePLAS3,4. The ePLAS model follows a laser generated hot electron component (fluid or particles) through background plasma of cold fluid electrons and ions. It allows for variations in the hot electron spectrum and directivity, and can suggest tuning...
In a Fast Ignition approach to achieving inertial confinement fusion (ICF) the processes of thermonuclear fuel compression and ignition are separated. The fusion fuel is partially compressed with a primary series of long-pulse, high energy lasers and in one scheme a single high power, short-pulse laser is used to drive a stream of energetic electrons into the core of the plasma to heat and ignite...
Fast Ignition [1] holds the promise of improved efficiency and reduced laser energy requirements for Laser Fusion Energy systems. The main approach proposed to date is by coupling a beam of 1 to 2 MeV electrons from the laser interaction spot to a 40 micron spot in the compressed fuel core using a metal cone insert to get close to the compressed core [2]. However, multi-millijoule level laser prepulse...
During the transit of an electron beam through a background plasma, instabilities can occur that may result in highly dynamic behaviour. This behaviour may be important in fast-ignition inertial confinement fusion. In one method of this type of fusion, a deuterium-tritium pellet is compressed by lasers to very high densities. An ignition laser pulse then interacts with a directional gold cone to produce...
Z-pinch driven inertial confinement fusion (ICF) is a fascinating object, and much progress had been obtained on Z machine by using the dynamic hohlraum concept, in which high velocity wire-array plasma impacts low-Z foam to create a hohlraum, where a DT capsule is imploded to ignition. In this report we discuss the collision and energy transfer between the wire-array and low density foam. And this...
The initiation of the explosive electron emission pulses - ectons being responsible for the ignition and burning of a vacuum discharge, in particular, - unipolar arcs1. The latter being a common feature of intense plasma-surface interactions in fusion devices. A fusion devices first wall with a strongly non-uniform surface, as well as an intense power load onto the surface in the edge localized modes...
Plasma ignition of solid propellant is a crucial and challenging task in the development of the electrothermal-chemical (ETC) gun technology. In this work, an attempt is made to develop a model for the ignition process of solid propellant submitted to a plasma flux. Comprehensive physical and chemical processes are taken into account, including the heat conduction in the solid propellant, heat release...
Over past decades, microplasma devices (MPDs) became popular research subject for their unique properties and wide range of applications, such as optical emitters, transistors, electron/ion sources, etc. However, MPD integration into electric circuits for consequent transition into industrial applications requires both reduction of MPD sizes and more detailed understanding of the physics behind its...
The ePLAS implicit simulation code1 is being used to study various focusing aids for hot electron directivity in Fast Igintion2. The ePLAS model can follow a laser generated hot electron component (fluid or particles) through background plasma consisting of cold fluid electrons and ions. The code captures eMHD3 effects, which can enhance B-field penetration in steep density gradient regions. The E-...
Sufficient alpha particle confinement is critical to ignition in Inertial Confinement Fusion (ICF). We assess the proportion of alpha particle energy lost by the hotspot during deceleration and burn, and how this depends on perturbation amplitude as well as hotspot temperature and areal density. The alpha particle transport is modeled using a particle pusher1 in which computational macroparticles...
NIF's ignition campaign has attracted a great attention recently due to its significance to the future of fusion researches worldwide. Recent experiment results have demonstrated both hopes as well as challenges faced by the NIF team. One of the greatest challenges is to achieve desired areal density ρR for both fuel and hot-spot regions so that a self-sustained TN burn could be initiated and maintained...
It had been noticed long ago1 that the requirements for inertial confinement fusion (ICF) ignition in a cylindrical target can be significantly relaxed if the plasma were compressed simultaneously with the flux of the entrained magnetic field from its seeded value ∼100 kG to the peak value of ∼100 MG. The ultrahigh axial magnetic field insulates the hot spot from the cold walls compressing it and...
A growing topic of interest in the field of nonequilibrium plasmas is the use of very short pulsed corona discharges for different applications such as ignition, flow control and gas cleaning [1, 2]. More specifically, the use of nanosecond scale discharges generated under very strong overvoltages is very challenging since it can produce, for atmospheric conditions, large volumes of plasma, with high...
The reactive species production is very important for multitude of applications, such as biological sterilization and healing, plasma assisted ignition and combustion, surface treatment and destruction of the harmful substances and pollutions. The ignition of the air-fuel mixtures has received considerable attention in the recent years. The results various studies [1, 2] within the last decades show...
Hollow cathode based on thermionic electron emission serves as crucial component in electric propulsion systems where this cathode used as source of electrons for propellant ionization and ion beam neutralization. In this research, a novel design of the hollow cathode without the heater was studied in the diode mode operation. The simplicity of the cathode design and its unique ignition characteristics...
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