Academic literature on the topic 'Plasma non collisionels'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Plasma non collisionels.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Plasma non collisionels"
1
Zhang, Yanzeng, and Xian-Zhu Tang. "On the collisional damping of plasma velocity space instabilities." Physics of Plasmas 30, no. 3 (2023): 030701. http://dx.doi.org/10.1063/5.0136739.
Full textAbstract:
For plasma velocity space instabilities driven by particle distributions significantly deviated from a Maxwellian, weak collisions can damp the instabilities by an amount that is significantly beyond the collisional rate itself. This is attributed to the dual role of collisions that tend to relax the plasma distribution toward a Maxwellian and to suppress the linearly perturbed distribution function. The former effect can dominate in cases where the unstable non-Maxwellian distribution is driven by collisionless transport on a timescale much shorter than that of collisions, and the growth rate of the ideal instability has a sensitive dependence on the distribution function. The whistler instability driven by electrostatically trapped electrons is used as an example to elucidate such a strong collisional damping effect of plasma velocity space instabilities, which is confirmed by first-principles kinetic simulations.
2
Zhang, Yanzeng, Yuzhi Li, Bhuvana Srinivasan, and Xian-Zhu Tang. "Resolving the mystery of electron perpendicular temperature spike in the plasma sheath." Physics of Plasmas 30, no. 3 (2023): 033504. http://dx.doi.org/10.1063/5.0132612.
Full textAbstract:
A large family of plasmas has collisional mean-free-path much longer than the non-neutral sheath width, which scales with the plasma Debye length. The plasmas, particularly the electrons, assume strong temperature anisotropy in the sheath. The temperature in the sheath flow direction ([Formula: see text]) is lower and drops toward the wall as a result of the decompressional cooling by the accelerating sheath flow. The electron temperature in the transverse direction of the flow field ([Formula: see text]) not only is higher but also spikes up in the sheath. This abnormal behavior of [Formula: see text] spike is found to be the result of a negative gradient of the parallel heat flux of transverse degrees of freedom ( qes) in the sheath. The non-zero heat flux qes is induced by pitch-angle scattering of electrons via either their interaction with self-excited electromagnetic waves in a nearly collisionless plasma or Coulomb collision in a collisional plasma, or both in the intermediate regime of plasma collisionality.
3
Fan, Kaixuan, Xueqiao Xu, Ben Zhu, and Pengfei Li. "Kinetic Landau-fluid closures of non-Maxwellian distributions." Physics of Plasmas 29, no. 4 (2022): 042116. http://dx.doi.org/10.1063/5.0083108.
Full textAbstract:
New kinetic Landau-fluid closures, based on the cutoff Maxwellian distribution, are derived. A special static case is considered (the frequency [Formula: see text]). In the strongly collisional regime, our model reduces to Braginskii's heat flux model, and the transport is local. In the weak collisional regime, our model indicates that the heat flux is non-local and recovers the Hammett–Perkins model while the value of the cutoff velocity approaches to infinity. We compare the thermal transport coefficient [Formula: see text] of Maxwellian, cutoff Maxwellian and super-Gaussian distribution. The results show that the reduction of the high-speed tail particles leads to the corresponding reduction of the thermal transport coefficient [Formula: see text] across the entire range of collisionality, more reduction of the free streaming transport toward the weak collisional regime. In the collisionless limit, [Formula: see text] approaches to zero for the cutoff Maxwellian and the super-Gaussian distribution but remains finite for Maxwellian distribution. [Formula: see text] is complex if the cutoff Maxwellian distribution is asymmetric. The [Formula: see text] approaches to different convergent values in both collisionless and strongly collisional limit, respectively. It yields an additional streaming heat flux in comparison with the symmetric cutoff Maxwellian distribution. Furthermore, due to the asymmetric distribution, there is a background heat flux [Formula: see text] though there is no perturbation. The derived Landau-fluid closures are general for fluid moment models, and applicable for the cutoff Maxwellian distribution in an open magnetic field line region, such as the scape-off-layer of Tokamak plasmas, in the thermal quench plasmas during a tokamak disruption, and the super-Gaussian electron distribution function due to inverse bremsstrahlung heating in laser-plasma studies.
4
Bret, Antoine, and Ramesh Narayan. "Density jump for parallel and perpendicular collisionless shocks." Laser and Particle Beams 38, no. 2 (2020): 114–20. http://dx.doi.org/10.1017/s0263034620000117.
Full textAbstract:
AbstractIn a collisionless shock, there are no binary collisions to isotropize the flow. It is therefore reasonable to ask to which extent the magnetohydrodynamics (MHD) jump conditions apply. Following up on recent works which found a significant departure from MHD in the case of parallel collisionless shocks, we here present a model allowing to compute the density jump for collisionless shocks. Because the departure from MHD eventually stems from a sustained downstream anisotropy that the Vlasov equation alone cannot specify, we hypothesize a kinetic history for the plasma, as it crosses the shock front. For simplicity, we deal with non-relativistic pair plasmas. We treat the cases of parallel and perpendicular shocks. Non-MHD behavior is more pronounced for the parallel case where, according to MHD, the field should not affect the shock at all.
5
YANG, Wei, Fei GAO, and Younian WANG. "Conductivity effects during the transition from collisionless to collisional regimes in cylindrical inductively coupled plasmas." Plasma Science and Technology 24, no. 5 (2022): 055401. http://dx.doi.org/10.1088/2058-6272/ac56ce.
Full textAbstract:
Abstract A numerical model is developed to study the conductivity effects during the transition from collisionless to collisional regimes in cylindrical inductively coupled argon plasmas at pressures of 0.1–20 Pa. The model consists of electron kinetics module, electromagnetics module, and global model module. It allows for self-consistent description of non-local electron kinetics and collisionless electron heating in terms of the conductivity of homogeneous hot plasma. Simulation results for non-local conductivity case are compared with predictions for the assumption of local conductivity case. Electron densities and effective electron temperatures under non-local and local conductivities show obvious differences at relatively low pressures. As increasing pressure, the results under the two cases of conductivities tend to converge, which indicates the transition from collisionless to collisional regimes. At relatively low pressures the local negative power absorption is predicted by non-local conductivity case but not captured by local conductivity case. The two-dimensional (2D) profiles of electron current density and electric field are coincident for local conductivity case in the pressure range of interest, but it roughly holds true for non-local conductivity case at very high pressure. In addition, an effective conductivity with consideration of non-collisional stochastic heating effect is introduced. The effective conductivity almost reproduces the electron density and effective electron temperature for the non-local conductivity case, but does not capture the non-local relation between electron current and electric field as well as the local negative power absorption that is observed for non-local conductivity case at low pressures.
6
McCubbin, Andrew J., Gregory G. Howes, and Jason M. TenBarge. "Characterizing velocity–space signatures of electron energization in large-guide-field collisionless magnetic reconnection." Physics of Plasmas 29, no. 5 (2022): 052105. http://dx.doi.org/10.1063/5.0082213.
Full textAbstract:
Magnetic reconnection plays an important role in the release of magnetic energy and consequent energization of particles in collisionless plasmas. Energy transfer in collisionless magnetic reconnection is inherently a two-step process: reversible, collisionless energization of particles by the electric field, followed by collisional thermalization of that energy, leading to irreversible plasma heating. Gyrokinetic numerical simulations are used to explore the first step of electron energization, and we generate the first examples of field–particle correlation signatures of electron energization in 2D strong-guide-field collisionless magnetic reconnection. We determine these velocity space signatures at the x-point and in the exhaust, the regions of the reconnection geometry in which the electron energization primarily occurs. Modeling of these velocity–space signatures shows that, in the strong-guide-field limit, the energization of electrons occurs through bulk acceleration of the out-of-plane electron flow by the parallel electric field that drives the reconnection, a non-resonant mechanism of energization. We explore the variation of these velocity–space signatures over the plasma beta range [Formula: see text]. Our analysis goes beyond the fluid picture of the plasma dynamics and exploits the kinetic features of electron energization in the exhaust region to propose a single-point diagnostic, which can potentially identify a reconnection exhaust region using spacecraft observations.
7
Hong, Young-Hun, Tae-Woo Kim, Ju-Ho Kim, Yeong-Min Lim, Moo-Young Lee, and Chin-Wook Chung. "Experimental investigation on the hysteresis in low-pressure inductively coupled neon discharge." Physics of Plasmas 29, no. 9 (2022): 093506. http://dx.doi.org/10.1063/5.0092091.
Full textAbstract:
A hysteresis phenomenon observed in neon inductive discharge at low gas pressure is investigated in terms of the evolution of the electron energy distribution function (EEDF). Generally, the hysteresis phenomenon has been reported at high-pressure Ramsauer gas discharges. However, in neon plasma, we found that the hysteresis phenomenon occurs even at low gas pressure (5 mTorr). Furthermore, the hysteresis vanishes with an increase in the gas pressure (10 and 25 mTorr). To analyze this hysteresis, the EEDF is measured depending on the radio frequency power. The EEDF at 10 mTorr sustains the bi-Maxwellian distribution during an E–H transition. On the other hand, the EEDF at 5 mTorr changes dramatically between discharge modes. At 5 mTorr, the measured EEDF for the E mode has the Maxwellian distribution due to high collisional heating in the bulk plasma. The EEDF for the H mode has the bi-Maxwellian distribution because collisionless heating in the skin depth is dominant. This apparent evolution of the EEDF causes a nonlinear energy loss due to collisions during the discharge mode transition. Therefore, the plasma can maintain the H mode discharge with high ionization efficiency, even at a lower applied power, which results in the hysteresis.
8
Kaganovich, I. D., V. I. Demidov, S. F. Adams, and Y. Raitses. "Non-local collisionless and collisional electron transport in low-temperature plasma." Plasma Physics and Controlled Fusion 51, no. 12 (2009): 124003. http://dx.doi.org/10.1088/0741-3335/51/12/124003.
Full text
9
Alharbi, A., I. Ballai, V. Fedun, and G. Verth. "Waves in weakly ionized solar plasmas." Monthly Notices of the Royal Astronomical Society 511, no. 4 (2022): 5274–86. http://dx.doi.org/10.1093/mnras/stac444.
Full textAbstract:
ABSTRACT Here, we study the nature and characteristics of waves propagating in partially ionized plasmas in the weakly ionized limit, typical for the lower part of the solar atmosphere. The framework in which the properties of waves are discussed depends on the relative magnitude of collisions between particles, but also on the relative magnitude of the collisional frequencies compared to the gyro-frequency of charged particles. Our investigation shows that the weakly ionized solar atmospheric plasma can be divided into two regions, and this division occurs, roughly, at the base of the chromosphere. In the solar photosphere, the plasma is non-magnetized and the dynamics can described within the three-fluid framework, where acoustic waves associated to each species can propagate. Due to the very high concentration of neutrals, the neutral sound waves propagates with no damping, while for the other two modes the damping rate is determined by collisions with neutrals. The ion- and electron-related acoustic modes propagate with a cut-off determined by the collisional frequency of these species with neutrals. In the weakly ionized chromosphere, only electrons are magnetized, however, the strong coupling of charged particles reduces the working framework to a two-fluid model. The disassociation of charged particles creates electric currents that can influence the characteristic of waves. The propagation properties of waves with respect to the angle of propagation are studied with the help of polar diagrams.
10
Haggerty, Colby C., Antoine Bret, and Damiano Caprioli. "Kinetic simulations of strongly magnetized parallel shocks: deviations from MHD jump conditions." Monthly Notices of the Royal Astronomical Society 509, no. 2 (2021): 2084–90. http://dx.doi.org/10.1093/mnras/stab3110.
Full textAbstract:
ABSTRACT Shocks waves are a ubiquitous feature of many astrophysical plasma systems, and an important process for energy dissipation and transfer. The physics of these shock waves are frequently treated/modelled as a collisional, fluid magnetohydrodynamic (MHD) discontinuity, despite the fact that many shocks occur in the collisionless regime. In light of this, using fully kinetic, 3D simulations of non-relativistic, parallel propagating collisionless shocks comprised of electron-positron plasma, we detail the deviation of collisionless shocks form MHD predictions for varying magnetization/Alfvénic Mach numbers, with particular focus on systems with Alfénic Mach numbers much smaller than sonic Mach numbers. We show that the shock compression ratio decreases for sufficiently large upstream magnetic fields, in agreement with theoretical predictions from previous works. Additionally, we examine the role of magnetic field strength on the shock front width. This work reinforces a growing body of work that suggest that modelling many astrophysical systems with only a fluid plasma description omits potentially important physics.
Dissertations / Theses on the topic "Plasma non collisionels"
1
Granier, Camille. "Nouveaux développements sur la théorie des instabilités des feuilles de courant dans les plasmas non-collisionels." Electronic Thesis or Diss., Université Côte d'Azur, 2022. http://www.theses.fr/2022COAZ4109.
Full textAbstract:
La reconnexion magnétique est une modification de la topologie du champ magnétique, responsable de la libération explosive d'énergie magnétique dans les plasmas astrophysiques, comme dans le cas des orages magnétosphériques et des éjections de masse coronale, ainsi que dans les plasmas de laboratoire, comme dans le cas des crashs en dents de scie dans les tokamaks. Dans les plasmas sans collisions comme, par exemple, la magnétosphère et le vent solaire, l'inertie des électrons devient particulièrement pertinente pour provoquer la reconnexion dans les régions de courant localisé intense, appelées feuilles de courant. Dans ces environnements non collisionnels, la température peut souvent être anisotrope et les effets à l'échelle électronique sur le processus de reconnexion peuvent devenir non négligeables.Dans cette thèse, la stabilité des feuilles de courant bidimensionnelles dans des plasmas sans collisions avec un fort champ guide est analysée sur la base de modèles gyrofluides assumant des ions froids. Ces modèles peuvent prendre en compte une anisotropie de température d'équilibre, et un βe fini. Ce dernier est un paramètre correspondant au rapport entre la pression cinétique électronique d'équilibre et la pression magnétique.Nous dérivons et analysons une relation de dispersion pour le taux de croissance des modes tearing sans collisions tenant compte de l'anisotropie de la température d'équilibre des électrons. Les prédictions analytiques sont testées par des simulations numériques, montrant un très bon accord quantitatif.Dans le cas isotrope, en tenant compte des effets βe finis, nous observons une stabilisation du taux de croissance du mode tearing lorsque les effets du rayon de Larmor fini des électrons deviennent pertinents. Dans la phase non linéaire, des phases de ralentissement et des phases d'accélération sont observées, de manière similaire à ce qui se produit en présence d'effets de rayon de Larmor fini ionique.Nous étudions également les conditions de stabilité marginale des feuilles de courant secondaires, pour le développement de plasmoïdes, dans des plasmas sans collisions. Dans le régime isotrope βe → 0, nous analysons la géométrie qui caractérise le feuillet de courant, et identifions les conditions pour lesquelles elle devient instable à l'instabilité plasmoïde. Notre étude montre que des plasmoïdes peuvent être obtenus, dans ce contexte, à partir de feuille de courants aillant un rapport d'aspect beaucoup plus petit que dans le régime collisionnel. De plus, nous étudions la formation de plasmoïdes en comparant les simulations gyrofluides et gyrocinétiques.Ceci a permis de montrer que l'effet de βe favorise l'instabilité plasmoïde. Enfin, nous étudions l'impact de la fermeture appliquée sur les moments, effectuée lors de la dérivation du modèle gyrofluide, sur la distribution et la conversion de l'énergie lors de la reconnexion<br>Magnetic reconnection is a change of topology of the magnetic field, responsible for explosive release of magnetic energy in astrophysical plasmas, as in the case of magnetospheric substorms and coronal mass ejections, as well as in laboratory plasmas, which is the case of sawtooth crashes in tokamaks. In collisionless plasmas as, for instance, the magnetosphere and the solar wind, electron inertia becomes particularly relevant to drive reconnection at regions of intense localized current, denoted as current sheets. In these non-collisional environments, the temperature can often be anisotropic and effects at the electron scale on the reconnection process can become non-negligible.In this thesis, the stability of two-dimensional current sheets, with respect to reconnecting perturbations, in collisionless plasmas with a strong guide field is analysed on the basis of gyrofluid models assuming cold ions. These models can take into account an equilibrium temperature anisotropy,and a finite βe, a parameter corresponding to the ratio between equilibrium electron kinetic pressure and magnetic pressure.We derive and analyze a dispersion relation for the growth rate of collisionless tearing modes accounting for equilibrium electron temperature anisotropy. The analytical predictions are tested against numerical simulations, showing a very good quantitative agreement.In the isotropic case, accounting for finite βe effects, we observe a stabilization of the tearing growth rate when electron finite Larmor radius effects become relevant. In the nonlinear phase, stall phases and faster than exponential phases are observed, similarly to what occurs in the presence of ion finite Larmor radius effects.We also investigate the marginal stability conditions of secondary current sheets, for the development of plasmoids, in collisionless plasmas. In the isotropic βe → 0 regime, we analyze the geometry that characterizes the reconnecting current sheet, and identify the conditions for which it is plasmoid unstable. Our study shows that plasmoids can be obtained, in this context, from current sheets with an aspect ratio much smaller than in the collisional regime. Furthermore, we investigate the plasmoid formation comparing gyrofluid and gyrokinetic simulations.This made it possible to show that the effect of finite βe, promotes the plasmoid instability. Finally, we study the impact of the closure applied on the moments, performed during the derivation of the gyrofluid model, on the distribution and conversion of energy during reconnection<br>La riconnessione magnetica è un cambiamento nella topologia delcampo magnetico, responsabile del rilascio esplosivo di energia magnetica nei plasmiastrofisici, come nelle tempeste magnetosferiche e nelle espulsioni di massa coronale,nonché nei plasmi di laboratorio, come nel caso delle oscillazioni a dente di sega neitokamak. Nei plasmi non-collisionali come, ad esempio, la magnetosfera e il vento solare,l’inerzia elettronica diventa particolarmente efficace nel causare la riconnessionein regioni di corrente intensa e localizzata, detti strati di corrente. In tali plasmi noncollisionali,la temperatura può essere spesso anisotropa e gli effetti su scala elettronicasul processo di riconnessione possono diventare non trascurabili.In questa tesi, viene analizzata la stabilità di strati di corrente bidimensionali inplasmi non-collisionali con un forte campo guida, sulla base di modelli girofluidi cheassumono ioni freddi. Questi modelli possono tenere conto di un’anisotropia di temperaturadi equilibrio e di un βe finito. Quest’ultimo è un parametro corrispondente alrapporto tra la pressione cinetica elettronica di equilibrio e la pressione magnetica.Deriviamo e analizziamo una relazione di dispersione per il tasso di crescita dei moditearing non-collisionali tenendo conto dell’anisotropia della temperatura di equilibriodegli elettroni. Le previsioni analitiche sono verificate mediante simulazioni numeriche,che mostrano un ottimo accordo quantitativo. Nel caso isotropico, tenendoconto degli effetti di βe finito, si osserva una stabilizzazione del tasso di crescita delmodo tearing quando diventano rilevanti gli effetti del raggio finito di Larmor deglielettroni. Nella fase non lineare si osservano fasi di decelerazione e fasi di accelerazione,simili a quanto avviene in presenza di effetti del raggio di Larmor finito ionico.Studiamo anche le condizioni di stabilità marginale degli strati di corrente secondaria,per lo sviluppo di plasmoidi, in plasmi senza collisioni. Nel regime isotropicocon βe → 0, analizziamo la geometria che caratterizza lo strato di corrente e identifichiamole condizioni in cui esso diventa instabile a causa di un’instabilità che generaplasmoidi. Il nostro studio mostra che i plasmoidi possono essere ottenuti, in questocontesto, da strati di corrente aventi un rapporto d’aspetto molto più piccolo rispettoal regime collisionale. Inoltre, studiamo la formazione di plasmoidi confrontando simulazionigirofluidi e girocinetiche. Ciò ha permesso di dimostrare che l’effetto di βe promuove l’instabilità che genera plasmoidi. Infine, si studia l’impatto della chiusuraapplicata ai momenti, eseguita durante la derivazione del modello girofluido, sulla distribuzionee conversione dell’energia durante la riconnessione
2
Capdessus, Rémi. "Dynamique d'un plasma non collisionnel interagissant avec une impulsion laser ultra-intense." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR15268/document.
Full textAbstract:
L'interaction d'un plasma avec une impulsion laser-intense suscite de plus en plus d'intérêt du fait des progrès en matière de technologie laser d'outils numériques. La réaction du rayonnement affecte la dynamique des électrons, celle du rayonnement synchrotron, ainsi que celle des ions via le champ de séparation de charge, pour des intensités laser supérieures à 10puissance22 W/CM2. les équations cinétiques régissant le transport de particules à ultra-haute intensité ont été obtenues. La réaction du rayonnement implique la contraction du volum de l'epace des phases des électrons A l'aide de simulations numériques nous avons démontré la forte rétro-action que les effets collectifs induisent sur le rayonnement synchrotron généré par les électons accélérés. L'importance des effets collectifs dépend fortement de la masse des ions et de l'épaisseur du plasma considéré. Ces effets pourraient être vérifiés expérimentalement avec des cibles cryogéniques d'hydrogène<br>Résumé en anglais
3
Ruyer, Charles. "Kinetic instabilities in plasmas : from electromagnetic fluctuations to collisionless shocks". Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112370/document.
Full textAbstract:
Les chocs non-collisionnels jouent un rôle majeur dans de nombreux événements astrophysiques à haute densité d'énergie (sursauts gamma, restes de supernovæ, vents de pulsar...), et seraient responsables de la génération de particules supra-thermiques et de radiations. Les simulations ont démontré qu'en l’absence de champs magnétiques externes, des instabilités électromagnétiques peuvent prendre place lors de la collision de plasmas à haute vitesse. Les instabilités du type Weibel sont en effet capables de faire croître, dans ces milieux, une turbulence électromagnétique potentiellement en mesure de défléchir et d'accélérer des particules par des processus du type Fermi. En plus d'une compréhension théorique toujours croissante, la génération expérimentale de tels chocs est maintenant étudiée à l'aide de lasers de puissance. Les fluctuations thermiques électromagnétiques constituent les germes des instabilités se développant dans un plasma. Nous nous sommes attelés à leur description dans le cas d’un plasma relativiste régi par une fonction de distribution de type Maxwell-Jüttner. Des formules exactes de la densité spectrale ont pu être obtenues pour différentes orientations du vecteur propre. Ces résultats ont pu être confrontés aux prédictions d’un code de simulation particle-in-cell (PIC). Un très bon accord a été démontré.Ces résultats ont été exploités lors d'une collaboration internationale dont le but était d'estimer le temps de saturation de l'instabilité cinétique de Weibel, générant des fluctuations magnétiques. Les estimations obtenues ont pu être validées par des simulations PIC sur trois ordres de grandeur d'énergie de dérive.Nous avons ensuite mené une étude théorique et numérique des collisions de plasma d'électrons-ions en régime non-collisionnel ayant lieu lors d'événements astrophysiques tels que les restes de supernovæ. Par-delà un intérêt académique pour la compréhension des processus de transfert/transport d’énergie au sein des plasmas, la récente génération de tels plasmas en laboratoire ouvre des perspectives inédites en astrophysique des hautes énergies. La zone de recouvrement de ces faisceaux de particules est sujette à des instabilités cinétiques du type Weibel, générant des champs magnétiques intenses.Nous avons modélisé l'évolution non-linéaire d'un système soumis à l'instabilité de Weibel, et obtenu des formules analytiques de l'évolution des paramètres plasmas (températures et vitesse de dérive) et des champs magnétiques. Le modèle prédit ainsi l’évolution du système jusqu’à un stade proche de l’isotropisation complète des populations de particules et donc jusqu'à la formation d’un choc non-collisionnel. Ce modèle, en accord avec des simulations du type « particle-in-cell », pu aussi être comparé à des résultats expérimentaux récents. L'étude de la propagation des chocs non-collisionnels, m'a permis de généraliser le précédent modèle au cas de la turbulence magnétique ayant lieu en amont du front de choc.Nous nous sommes consacrés enfin aux chocs non-collisionnels créés dans un plasma dense (opaque) irradié par un laser intense. L’interaction laser-plasma qui en résulte donne lieu à un important courant d'électrons relativistes qui sont à l’origine d’instabilités cinétiques (de filamentation notamment) susceptibles d'évoluer en choc non-collisionnel. Une observation originale, contrastant avec les premières publications sur le sujet est que pour les paramètres considérés (un laser d’éclairement ~1021 Wcm-2, interagissant avec une cible solide), le choc résulte de la turbulence magnétique produite par l’instabilité électronique, plutôt que par l’instabilité ionique (dont la croissance est plus tardive). En d’autres termes, compte tenu de l’énergie très élevée des électrons accélérés par le laser, la turbulence qu'ils génèrent s’avère assez forte pour rapidement défléchir les ions<br>Collisionless shocks play a major role in powerful astrophysical objects (e.g., gamma-ray bursts, supernova remnants, pulsar winds, etc.), where they are thought to be responsible for non-thermal particle acceleration and radiation. Numerical simulations have shown that, in the absence of an external magnetic field, these self-organizing structures originate from electromagnetic instabilities triggered by high-velocity colliding flows. These Weibel-like instabilities are indeed capable of producing the magnetic turbulence required for both efficient scattering and Fermi-type acceleration. Along with rapid advances in their theoretical understanding, intense effort is now underway to generate collisionless shocks in the laboratory using energetic lasers. In a first part we study the (w,k)-resolved electromagnetic thermal spectrum sustained by a drifting relativistic plasma. In particular, we obtain analytical formulae for the fluctuation spectra, the latter serving as seeds for growing magnetic modes in counterstreaming plasmas. Distinguishing between subluminal and supraluminal thermal fluctuations, we derived analytical formulae of their respective spectral contributions. Comparisons with particle-in-cell (PIC) simulations are made, showing close agreement in the subluminal regime along with some discrepancy in the supraluminal regime. Our formulae are then used to estimate the saturation time of the Weibel instability of relativistic pair plasmas. Our predictions are shown to match 2-D particle-in-cell (PIC) simulations over a three-decade range in flow energyWe then develop a predictive kinetic model of the nonlinear phase of the Weibel instability induced by two counter-streaming, symmetric and non-relativistic ion beams. This self consistent, fully analytical model allows us to follow the evolution of the beams' properties up to a stage close to complete isotropization and thus to shock formation. Its predictions are supported by 2D and 3D particle-in-cell (PIC) simulations of the ion Weibel instability in uniform geometries, as well as shock-relevant non-uniform configurations. Moreover, they are found in correct agreement with a recent laser-driven plasma collision experiment. Along with this comparison, we pinpoint the important role of electron screening on the ion-Weibel dynamics, which may affect the results of simulations with artificially high electron mass. We subsequently address the shock propagation resulting from the magnetic Weibel turbulence generated in the upstream region. Generalizing the previous symmetric-beam model to the upstream region of the shock, the role of the magnetic turbulence in the shock-front has been analytically and self-consistently characterized. Comparison with simulations validates the model. The interaction of high-energy, ultra-high intensity lasers with dense plasmas is known to produce copious amounts of suprathermal particles. Their acceleration and subsequent transport trigger a variety of Weibel-like electromagnetic instabilities, acting as additional sources of slowing down and scattering. Their understanding is important for the many applications based upon the energy deposition and/or field generation of laser-driven particles. We investigate the ability of relativistic-intensity laser pulses to induce Weibel instability-mediated shocks in overdense plasma targets, as first proposed by Fiuza in 2012. By means of both linear theory and 2D PIC simulations, we demonstrated that in contrast to the standard astrophysical scenario previously addressed, the early-time magnetic fluctuations (Weibel instability) generated by the suprathermal electrons (and not ions) are strong enough to isotropize the target ions and, therefore, induce a collisionless electromagnetic shock
4
Figua, Habiba. "Contribution des codes euleriens en physique des plasmas non collisionnels." Orléans, 1999. http://www.theses.fr/1999ORLE2037.
Full textAbstract:
Ce travail rentre dans le cadre de la simulation numerique des problemes fortement nonlineaires en physique des plasmas non collisionnels. A cet effet, nous avons etudie trois aspects differents de ces problemes. Le premier chapitre traite l'expansion d'un plasma constitue de trois especes (electrons, ions positifs et ions negatifs). Les equations de bases sont ecrites dans une nouvelle echelle en espace et en temps a l'aide des transformations du redimensionnement qui absorbent analytiquement l'expansion. Dans ce plasma, la temperature decroit en t - 2 et le nouveau temps est une compression logarithmique. Les resultats numeriques sont donnes par un code eulerien. La simulation numerique du systeme vlasov-poisson exhibe une filamentation dans l'espace des phases. Dans le deuxieme chapitre nous etudions une nouvelle methode introduite par a. Klimas dans le but de remedier a cette filamentation. Cette methode consiste a convoler la fonction de distribution avec une gaussienne en vitesse. Nous etudions la stabilite du systeme vlasov-poisson qui decoule de cette operation, ensuite nous montrons la necessite de la transformee de fourier en les variables d'espace et de vitesse pour la resolution de cette nouvelle equation. Bien que l'entropie soit theoriquement un invariant du systeme vlasov-poisson, elle presente une croissance numerique. Ce phenomene se traduit par une perte d'information. Dans le troisieme chapitre nous evaluons cette perte.
5
Grassi, Anna. "Collisionless shocks in the context of Laboratory Astrophysics." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066483/document.
Full textAbstract:
Cette thèse s'inscrit dans le cadre de l'astrophysique de laboratoire. Nous abordons divers aspects de la physique des chocs non-collisionels en présence de flots de plasma relativistes dans des configurations d'intérêt pour les communautés astrophysique et de l’interaction laser-plasma (ILP). Notre approche repose sur la modélisation analytique et la simulation cinétique haute-performance, outil central pour décrire les processus d'ILP et la physique non linéaire à l'origine des chocs étudiés. Le code Particle-in-Cell SMILEI a été largement utilisé et développé au cours ce travail. Trois configurations physiques sont étudiées. L’instabilité Weibel en présence de faisceaux d'électrons contre-propagatifs alignés avec un champ magnétique externe est décrite. Les phases linéaires et non linéaires sont expliquées à l’aide de modèles théoriques confirmés par des simulations. La génération de chocs non-collisionels lors de l’interaction de deux plasmas relativistes de paires est étudiée en présence d’un champ magnétique perpendiculaire. L’accent est mis sur la comparaison des prédictions théoriques sur les grandeurs macroscopiques avec les simulations, ainsi que sur la définition du temps de formation du choc, l’ensemble de ces grandeurs étant d’une grande importance pour de futures expériences. Enfin, nous proposons un schéma permettant de recréer, en laboratoire, l’instabilité Weibel ionique par l'utilisation d'un laser intense. Les flots de plasmas produits ici sont plus rapides et denses que dans les expériences actuelles, conduisant à un taux de croissance et des champs magnétiques plus élevés. Ces résultats sont également important pour l’ILP à très haute intensité<br>The work presented in this thesis belongs to the general framework of Laboratory Astrophysics. We address various aspects of the physics of collisionless shocks developing in the presence of relativistic plasma flows, in configurations of interest for the astrophysical and the laser-plasma interaction (LPI) communities. The approach used throughout this thesis relied on both analytical modeling and high-performance kinetic simulations, a central tool to describe LPI processes as well as the non-linear physics behind shock formation. The PIC code SMILEI has been widely used and developed during this work. Three physical configurations are studied. First we consider the Weibel instability driven by two counter-streaming electron beams aligned with an external magnetic field. The linear and non-linear phases are explained using theoretical models confirmed by simulations.Then the generation of non-collisional shocks during the interaction of two relativistic plasma pairs is studied in the presence of a perpendicular magnetic field. We focus on the comparison of theoretical predictions for macroscopic variables with the simulation results, as well as on the definition and measurement of the shock formation time, all of which are of great importance for future experiments.Finally, we proposed a scheme to produce, in the laboratory, the ion-Weibel-instability with the use of an ultra-high-intensity laser. The produced flows are faster and denser than in current experiments, leading to a larger growth rate and stronger magnetic fields. These results are important for the LPI at very high intensity
6
Moreno-Gelos, Quentin. "Non-relativistic collisionless shocks in Laboratory Astrophysics." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0427/document.
Full textAbstract:
Les chocs sans collision sont omniprésents dans l'Univers, notamment dans les restes de supernova, et sont formés via diverses instabilités plasmas dépendant essentiellement de la vitesse et de la magnétisation des flux de plasmas. La description de tels chocs nécessite une approche cinétique, tant analytique que numérique.Dans cette thèse, nous avons étudié, au travers de simulations Particle-In-Cell (PIC), les processus sous-jacents par lesquels les instabilités rentrent en compétition les unes avec les autres. Nous avons montré que la diminution du rapport des masses entre ions et électrons, souvent utilisée en simulations numériques pour accélérer la dynamique des chocs, peut avoir de fortes conséquences sur le transfert d'énergie entre particules durant la phase non-linéaire des instabilités.Ces dernières, comme l'instabilité acoustique ionique (IAI) amènent sous certaines conditions à la formation de chocs électrostatiques, pouvant donner naissance à la formation de trous dans l'espace des phases, se propageant dans la région aval du choc, et accélérant ce dernier. L'ajout d'un champ magnétique externe conduit à un changement de médiation du choc, pouvant varier entre l'IAI et les ondes magnéto-soniques lente ou rapide en fonction de l'obliquité entre le champ magnétique et la normale au choc. De plus, nous avons montré que l'orientation du champ magnétique permet de choisir entre une dispersion convexe ou concave des ondes plasma conduisant à la création d'ondes précurseurs dans les régions amont ou aval du choc.Ces chocs magnétisés se trouvent être correctement représentés par le modèle magnétohydrodynamique (MHD) tant qu'ils restent laminaire et que leur potentiel dans la région aval n'est pas suffisamment grand pour réfléchir les particules du milieu amont.Nous avons montré que même pour des chocs sous critiques, une fraction d'ions réfléchis, ne pouvant pas être représentés par la MHD, est suffisante à la croissance d'ondes solitaires en amont du choc, conduisant à l’accélération de ce dernier, mais pas à un processus d'auto-reformation comme pour les chocs super critiques.Bien que les échelles spatio-temporelles soient très différentes, les lois d'échelle rendent possible l'étude de tels phénomènes en laboratoire. Nos études numériques ont été faites dans un cadre de type tube à choc pouvant être testé expérimentalement.A ce titre, nous proposons dans cette thèse une expérience sur la création d'îlots magnétiques, formés par l’interaction de plasmas générés par l'irradiation de cibles par laser baignant dans un champ magnétique externe, et conduisant à la formation de tels chocs.Enfin, nous avons démontré expérimentalement et numériquement la formation de chocs électromagnétiques sans collisions par le biais de l'instabilité de Weibel stimulée par l'instabilité de batterie Biermann, conduisant à l'accélération de particules par le mécanisme de Fermi. Ce nouveau type d'expérience pourrait expliquer l'origine du rayonnement cosmique provenant des restes de supernova<br>Collisionless shocks are ubiquitous in the Universe, especially in the supernova remnants, and are formed via various plasma instabilities mainly depending on the speed and magnetization of plasma flows. The description of such shocks requires a kinetic approach, both analytical and numerical.In this thesis, we have studied, through Particle-In-Cell (PIC) simulations, the underlying processes by which instabilities compete with each other.We have shown that the reduction of the ion-to-electron mass ratio, often used in numerical simulations to accelerate the dynamics of shocks, can have strong consequences on the energy transfer between particles during the non-linear phase of instabilities.These instabilities, like the ionic acoustic instability (IAI) lead under certain conditions to the formation of electrostatic shocks, which can give rise to phase space holes formation, propagating in the downstream shock region, and accelerating the shock.The addition of an external magnetic field leads to different shock mediation, which can vary between the IAI to the slow or fast magneto-sonic waves as a function of the obliquity between the magnetic field and the shock normal.Furthermore, we have shown that the orientation of the magnetic field makes it possible to choose between a convex or concave dispersion of the plasma waves leading to the creation of precursor waves in the upstream or downstream shock regions.These magnetized shocks are correctly represented by the magnetohydrodynamic (MHD) model as long as they remain laminar and their potential in the downstream region is not large enough to reflect the particles of the upstream medium.We have shown that even for sub-critical shocks, a fraction of reflected ions, which cannot be modeled by the MHD, is sufficient for the growth of solitary waves upstream of the shock, leading to the acceleration of the latter, but not to a process of 'self-reformation' as for super-critical shocks.Although spatio-temporal scales are very different, scaling laws make possible the study of such phenomena in the laboratory. Our numerical studies have been done in the context of shock tubes that can be experimentally tested.As such, we propose in this thesis an experiment on the creation of magnetic islands, formed by the interaction of plasmas generated by the irradiation of laser targets bathed in an external magnetic field, leading to the formation of such shocks.Finally, we experimentally and numerically demonstrated the formation of collisionless electromagnetic shocks through the Weibel instability stimulated by theBiermann Battery instability, and leading to particle acceleration by the Fermi mechanism.This new type of experiment could explain the origin of cosmic radiation from supernova remnants
7
Saussede, Florence. "Simulation numérique d'un choc non collisionnel en physique des plasmas." Bordeaux 1, 1993. http://www.theses.fr/1993BOR10546.
Full textAbstract:
Un modele de representation hybride, adoptant une description cinetique des ions et hydrodynamique des electrons est mis en place pour simuler le probleme unidimensionnel d'un choc non collisionnel en physique des plasmas. Les modeles hybrides standards tiennent compte de certaines hypotheses simplificatrices (masse electronique nulle, quasi-neutralite, approximation de darwin) qui reduisent le systeme d'equations initial et facilitent ainsi l'analyse numerique du probleme. Afin d'elargir le domaine d'application du modele, nous levons ces hypotheses et considerons le systeme d'equations complet. La difficulte majeure de cette etude tient dans le choix d'une methode de resolution qui soit a la fois stable et performante. La methode implicite mise en uvre et appelee methodes des moments implicites, permet de s'affranchir a moindre cout des problemes de stabilite rencontres lors du couplage des equations d'euler, vlasov et maxwell. Cette methode originale evite, en effet, la lourdeur des schemas implicites classiques tout en permettant l'acces a des temps de calcul raisonnables
8
Musatenko, Kateryna. "Analyse des caractéristiques d'ondes au voisinage des chocs dans des plasmas spatiaux : observations des satellites CLUSTER, modélisation et interprétation." Phd thesis, Université d'Orléans, 2009. http://tel.archives-ouvertes.fr/tel-00452683.
Full textAbstract:
Cette thèse est consacrée à l'étude des processus d'ondes au voisinage des chocs dans les plasmas spatiaux. La propagation des ondes de Langmuir dans un plasma présentant des inhomogénéités aléatoires de densité a été modélisée numériquement; les résultats obtenus ont été comparés aux données des instruments WHISPER et WBD à bord des satellites CLUSTER. Les résultats de modélisation et l'étude statistique portant sur l'intensité des ondes de Langmuir observées dans le préchoc terrestre et le vent solaire ont montré que le théorème central limite n'est pas applicable aux statistiques sur l'intensité, du fait du nombre insuffisant d'inhomogénéités. Il en résulte que la fonction de distribution de probabilité pour le logarithme des énergies d'ondes n'atteint pas la distribution normale. D'autre part la détection à distance de la zone quasi-perpendiculaire du front de choc terrestre a pu être effectuée en analysant la modulation des ondes de Langmuir et celle des ondes électrostatiques avec fréquence décalée à proximité de la limite du pré-choc. Il a été montré que la probabilité d'observation de la non-stationnarité du front de choc augmente avec le nombre de Mach du choc. Enfin le rayonnement de transition des électrons relativistes au front de choc quasi-perpendiculaire a été calculé pour expliquer le mécanisme de l'émission électromagnétique observée par les satellites près du front de choc interplanétaire le 22 janvier 2004. Les paramètres du calcul correspondent aux véritables paramètres de l'évènement. Le spectre du rayonnement de transition établi théoriquement a son maximum dans le même domaine de fréquence que pour les mesures.
9
Pantellini, Filippo. "Etude de la structure des chocs non collisionnels dans les plasmas spatiaux." Paris 7, 1992. http://www.theses.fr/1992PA077148.
Full textAbstract:
Les resultats de simulations d'un choc non collisionnel supercritique en propagation quasi-parallele par rapport a un champ magnetostatique sont presentes. Un code particulaire bidimensionnel, avec des ions et des electrons se deplacant dans un champ electromagnetique autoconsistant, est utilise. Il est montre, par exemple, que la croissance d'ondes de sifflement en amont de la transition principale du choc est une des raisons de la non-stationnarite des chocs quasi-paralleles
10
Melzani, Mickaël. "Reconnexion magnétique non-collisionelle dans les plasmas relativistes et simulations particle-in-cell." Thesis, Lyon, École normale supérieure, 2014. http://www.theses.fr/2014ENSL0946/document.
Full textAbstract:
L'objectif de cette thèse est l'étude de la reconnexion magnétique dans les plasmas non-collisionels et relativistes. De tels plasmas sont présents dans divers objets astrophysiques (MQs, AGNs, GRBs...), où la reconnexion pourrait expliquer la production de particules et de radiation de haute énergie, un chauffage, ou des jets. Une compréhension fondamentale de la reconnexion n'est cependant toujours pas acquise, en particulier dans les plasmas relativistes ion-électron. Nous présentons d'abord les bases de la reconnexion magnétique. Nous démontrons des résultats particuliers à la physique des plasmas relativistes, concernant par exemple la distribution de Maxwell-Jüttner. Ensuite, nous réalisons une étude détaillée de l'outil numérique utilisé : les simulations particle-in-cell (PIC). Le fait que le plasma réel contienne beaucoup plus de particules que le plasma PIC a des conséquences importantes (collisionalité, relaxation, bruit) que nous décrivons. Enfin, nous étudions la reconnexion magnétique dans les plasmas ion-électron et relativistes à l'aide de simulations PIC. Nous soulignons des points spécifiques : loi d'Ohm (l'inertie de bulk dominante), zone de diffusion, taux de reconnexion (et sa normalisation relativiste). Les ions et les électrons produisent des lois de puissance, avec un index qui dépend de la vitesse d'Alfvén et de la magnétisation, et qui peut être plus dur que dans le cas des chocs non-collisionels. De plus, les ions peuvent avoir plus ou moins d'énergie que les électrons selon la valeur du champ guide. Ces résultats fournissent une base solide à des modèles d'objets astrophysiques qui, jusque là, supposaient a priori ces résultats<br>The purpose of this thesis is to study magnetic reconnection in collisionless and relativistic plasmas. Such plasmas can be encountered in various astrophysical objects (microquasars, AGNs, GRBs...), where reconnection could explain high-energy particle and photon production, plasma heating, or transient large-scale outflows. However, a first principle understanding of reconnection is still lacking, especially in relativistic ion-electron plasmas. We first present the basis of reconnection physics. We derive results relevant to relativistic plasma physics, including properties of the Maxwell-Jüttner distribution. Then, we provide a detailed study of our numerical tool, particle-in-cell simulations (PIC). The fact that the real plasma contains far less particles than the PIC plasma has important consequences concerning relaxation times or noise, that we describe. Finally, we study relativistic reconnection in ion-electron plasmas with PIC simulations. We stress outstanding properties: Ohm's law (dominated by bulk inertia), structure of the diffusion zone, energy content of the outflows (thermally dominated), reconnection rate (and its relativistic normalization). Ions and electrons produce power law distributions, with indexes that depend on the inflow Alfvén speed and on the magnetization of the corresponding species. They can be harder than those produced by collisionless shocks. Also, ions can get more or less energy than the electrons, depending on the guide field strength. These results provide a solid ground for astrophysical models that, up to now, assumed with no prior justification the existence of such distributions or of such ion/electron energy repartition
Books on the topic "Plasma non collisionels"
1
Morawetz, Klaus. Deep Impurities with Collision Delay. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198797241.003.0017.
Full textAbstract:
The linearised nonlocal kinetic equation is solved analytically for impurity scattering. The resulting response function provides the conductivity, plasma oscillation and Fermi momentum. It is found that virial corrections nearly compensate the wave-function renormalizations rendering the conductivity and plasma mode unchanged. Due to the appearance of the correlated density, the Luttinger theorem does not hold and the screening length is influenced. Explicit results are given for a typical semiconductor. Elastic scattering of electrons by impurities is the simplest but still very interesting dissipative mechanism in semiconductors. Its simplicity follows from the absence of the impurity dynamics, so that individual collisions are described by the motion of an electron in a fixed potential.
Book chapters on the topic "Plasma non collisionels"
1
Tsytovich, Vadim N. "Fluctuations and Particle Collisions." In Lectures on Non-linear Plasma Kinetics. Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-78902-1_4.
Full text
2
Novikov, Vladimir G. "Average Atom Approximation in Non-LTE Level Kinetics." In Modern Methods in Collisional-Radiative Modeling of Plasmas. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-27514-7_5.
Full text
3
Ferland, G. J., and R. J. R. Williams. "Spectral Modeling in Astrophysics—The Physics of Non-equilibrium Clouds." In Modern Methods in Collisional-Radiative Modeling of Plasmas. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-27514-7_7.
Full text
4
Bykov, A. M., M. A. Malkov, J. C. Raymond, A. M. Krassilchtchikov, and A. E. Vladimirov. "Collisionless Shocks in Partly Ionized Plasma with Cosmic Rays: Microphysics of Non-thermal Components." In Microphysics of Cosmic Plasmas. Springer US, 2013. http://dx.doi.org/10.1007/978-1-4899-7413-6_19.
Full text
5
Korol, Andrey V., and Andrey V. Solov’yov. "PBrS in Non-Relativistic Collisions of Structural Particles with Atoms and Ions." In Springer Series on Atomic, Optical, and Plasma Physics. Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-45224-6_5.
Full text
6
Stock, Reinhard. "Relativistic Nucleus-Nucleus Collisions and the QCD Matter Phase Diagram." In Particle Physics Reference Library. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-38207-0_7.
Full textAbstract:
AbstractThis review will be concerned with our knowledge of extended matter under the governance of strong interaction, in short: QCD matter. Strictly speaking, the hadrons are representing the first layer of extended QCD architecture. In fact we encounter the characteristic phenomena of confinement as distances grow to the scale of 1 fm (i.e. hadron size): loss of the chiral symmetry property of the elementary QCD Lagrangian via non-perturbative generation of “massive” quark and gluon condensates, that replace the bare QCD vacuum. However, given such first experiences of transition from short range perturbative QCD phenomena (jet physics etc.), toward extended, non perturbative QCD hadron structure, we shall proceed here to systems with dimensions far exceeding the force range: matter in the interior of heavy nuclei, or in neutron stars, and primordial matter in the cosmological era from electro-weak decoupling (10−12 s) to hadron formation (0.5 ⋅ 10−5 s). This primordial matter, prior to hadronization, should be deconfined in its QCD sector, forming a plasma (i.e. color conducting) state of quarks and gluons: the Quark Gluon Plasma (QGP).
7
Wilson, G. R. "Development of non-Maxwellian velocity distributions as a consequence of nonlocal Coulomb collisions." In Cross‐Scale Coupling in Space Plasmas. American Geophysical Union, 1995. http://dx.doi.org/10.1029/gm093p0047.
Full text
8
Ogoyski, A. I., and A. B. Blagoev. "Diffusion and Depopulation of the Metastable Cd 3 P0,2 States in Collisions with Neon Atoms." In Advanced Technologies Based on Wave and Beam Generated Plasmas. Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-017-0633-9_35.
Full text
9
"Dynamics of Collisionless Plasma." In Field Theory of Non-Equilibrium Systems, 2nd ed. Cambridge University Press, 2023. http://dx.doi.org/10.1017/9781108769266.009.
Full text
10
Bers, Abraham. "Kinetic theory of collisions and transport—II. Weakly-ionized plasmas." In Plasma Physics and Fusion Plasma Electrodynamics. Oxford University PressOxford, 2016. http://dx.doi.org/10.1093/acprof:oso/9780199295784.003.0031.
Full textAbstract:
Abstract This chapter turns to weakly-ionized plasmas. It describes electron-neutral collisions and some of the resulting transport in applied EM fields. The simplified Lorentz model/operator, and the solution of the electron distribution function using an expansion in spherical harmonics analyzed here allows for rigorously defining various relaxation frequencies that were introduced in earlier chapters in an ad-hoc manner. The chapter then pays attention on finding the electrical conductivity in a weakly-ionized plasma in applied EM fields, and addresses diffusion and thermal conductivity and the important case of “intermediate plasmas.” The results of this chapter should be useful, notably in the following domains of study: gas discharges at low power; ionosphere up to an altitude of about 250 km; and dense and not too hot plasmas such as flames and magnetohydrodynamic energy converters.
Conference papers on the topic "Plasma non collisionels"
1
Quraishi, Qudsia. "Classical collisional diffusion in the annular Penning trap." In NON-NEUTRAL PLASMA PHYSICS IV: Workshop on Non-Neutral Plasmas. AIP, 2002. http://dx.doi.org/10.1063/1.1454311.
Full text
2
Bertsche, W. "Collisional Cooling of Pure Electron Plasmas Using CO2." In NON-NEUTRAL PLASMA PHYSICS V: Workshop on Non-Neutral Plasmas. AIP, 2003. http://dx.doi.org/10.1063/1.1635180.
Full text
3
Zwicknagel, G. "Energy loss of ions by collisions with magnetized electrons." In NON-NEUTRAL PLASMA PHYSICS IV: Workshop on Non-Neutral Plasmas. AIP, 2002. http://dx.doi.org/10.1063/1.1454322.
Full text
4
Kabantsev, Andrey A., and C. Fred Driscoll. "Trapped-Particle-Mediated Collisional Damping of Non-Axisymmetric Plasma Waves." In NON-NEUTRAL PLASMA PHYSICS VI: Workshop on Non-Neutral Plasmas 2006. AIP, 2006. http://dx.doi.org/10.1063/1.2387912.
Full text
5
Anderson, M. W., T. M. O’Neil, James R. Danielson, and Thomas Sunn Pedersen. "Collisional Damping Of Plasma Waves On A Pure Electron Plasma Column." In NON-NEUTRAL PLASMA PHYSICS VII: Workshop on Non-Neutral Plasmas 2008. AIP, 2009. http://dx.doi.org/10.1063/1.3122272.
Full text
6
Coppa, Gianni G. M. "Non-collisional kinetic model for non-neutral plasmas in a Penning trap: General properties and stationary solutions." In NON-NEUTRAL PLASMA PHYSICS IV: Workshop on Non-Neutral Plasmas. AIP, 2002. http://dx.doi.org/10.1063/1.1454327.
Full text
7
Driscoll, C. F., A. A. Kabantsev, D. H. E. Dubin, and Y. A. Tsidulko. "Transport, damping, and wave-couplings from chaotic and collisional neoclassical transport." In NON-NEUTRAL PLASMA PHYSICS VIII: 10th International Workshop on Non-Neutral Plasmas. AIP, 2013. http://dx.doi.org/10.1063/1.4796057.
Full text
8
Zwicknagel, Günter. "Ion–electron collisions in a homogeneous magnetic field." In Non-neutral plasma physics III. AIP, 1999. http://dx.doi.org/10.1063/1.1302150.
Full text
9
Hollmann, E. M., F. Anderegg, and C. F. Driscoll. "Measurement of cross-magnetic-field heat transport due to long range collisions." In Non-neutral plasma physics III. AIP, 1999. http://dx.doi.org/10.1063/1.1303710.
Full text
10
Dubin, Daniel H. E., and Dezhe Z. Jin. "2D collisional diffusion of rods in a magnetized plasma column with finite E×B shear." In Non-neutral plasma physics III. AIP, 1999. http://dx.doi.org/10.1063/1.1302123.
Full textReports on the topic "Plasma non collisionels"
1
Rosenberg, M., and Nicholas A. Krall. Collisional Relaxation of Non-Maxwellian Plasma Distribution in a Polywell (Tradename). Defense Technical Information Center, 1992. http://dx.doi.org/10.21236/ada257651.
Full text