skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Early Out-Of-Equilibrium Beam-Plasma Evolution

Abstract

We solve analytically the out-of-equilibrium initial stage that follows the injection of a radially finite electron beam into a plasma at rest and test it against particle-in-cell simulations. For initial large beam edge gradients and not too large beam radius, compared to the electron skin depth, the electron beam is shown to evolve into a ring structure. For low enough transverse temperatures, the filamentation instability eventually proceeds and saturates when transverse isotropy is reached. The analysis accounts for the variety of very recent experimental beam transverse observations.

Authors:
 [1];  [2];  [3];  [4]
  1. Laboratoire de Physique et Technologie des Plasmas (CNRS UMR 7648), Ecole Polytechnique, 91128 Palaiseau cedex (France)
  2. Laboratoire d'Optique Appliquee, ENSTA/Ecole Polytechnique (CNRS UMR 7639), 91761 Palaiseau cedex (France)
  3. Departement de Physique Theorique et Appliquee, CEA/DAM Ile-de-France, BP 12, 91680 Bruyeres-le-Chatel (France)
  4. Laboratoire de Physique des Gaz et des Plasmas (CNRS UMR 8578), Universite Paris XI, Batiment 210, 91405 Orsay cedex (France)
Publication Date:
OSTI Identifier:
20777110
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 96; Journal Issue: 11; Other Information: DOI: 10.1103/PhysRevLett.96.115004; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BEAM INJECTION; BEAM-PLASMA SYSTEMS; ELECTRON BEAMS; ELECTRONS; EQUILIBRIUM; EVOLUTION; ISOTROPY; PLASMA; PLASMA INSTABILITY; PLASMA SIMULATION

Citation Formats

Firpo, M.-C., Lifschitz, A.F., Lefebvre, E., and Deutsch, C. Early Out-Of-Equilibrium Beam-Plasma Evolution. United States: N. p., 2006. Web. doi:10.1103/PhysRevLett.96.115004.
Firpo, M.-C., Lifschitz, A.F., Lefebvre, E., & Deutsch, C. Early Out-Of-Equilibrium Beam-Plasma Evolution. United States. doi:10.1103/PhysRevLett.96.115004.
Firpo, M.-C., Lifschitz, A.F., Lefebvre, E., and Deutsch, C. Fri . "Early Out-Of-Equilibrium Beam-Plasma Evolution". United States. doi:10.1103/PhysRevLett.96.115004.
@article{osti_20777110,
title = {Early Out-Of-Equilibrium Beam-Plasma Evolution},
author = {Firpo, M.-C. and Lifschitz, A.F. and Lefebvre, E. and Deutsch, C.},
abstractNote = {We solve analytically the out-of-equilibrium initial stage that follows the injection of a radially finite electron beam into a plasma at rest and test it against particle-in-cell simulations. For initial large beam edge gradients and not too large beam radius, compared to the electron skin depth, the electron beam is shown to evolve into a ring structure. For low enough transverse temperatures, the filamentation instability eventually proceeds and saturates when transverse isotropy is reached. The analysis accounts for the variety of very recent experimental beam transverse observations.},
doi = {10.1103/PhysRevLett.96.115004},
journal = {Physical Review Letters},
number = 11,
volume = 96,
place = {United States},
year = {Fri Mar 24 00:00:00 EST 2006},
month = {Fri Mar 24 00:00:00 EST 2006}
}
  • Despite the importance of the Second Law of Thermodynamics, it is not absolute. Statistical mechanics implies that, given sufficient time, systems near equilibrium will spontaneously fluctuate into lower-entropy states, locally reversing the thermodynamic arrow of time. We study the time development of such fluctuations, especially the very large fluctuations relevant to cosmology. Under fairly general assumptions, the most likely history of a fluctuation out of equilibrium is simply the CPT conjugate of the most likely way a system relaxes back to equilibrium. We use this idea to elucidate the spacetime structure of various fluctuations in (stable and metastable) de Sittermore » space and thermal anti-de Sitter space.« less
  • Photoexcited strongly correlated materials is attracting growing interest since their rich phase diagram often translates into an equally rich out-of-equilibrium behavior, including non-thermal phases and photoinduced phase transitions. With femtosecond optical pulses, electronic and lattice degrees of freedom can be transiently decoupled, giving the opportunity of stabilizing new states of matter inaccessible by quasi-adiabatic pathways. We present a study of the ultrafast non-equilibrium evolution of the prototype Mott-Hubbard material V 2O 3, which presents a transient non-thermal phase developing immediately after photoexcitation and lasting few picoseconds. For both the insulating and the metallic phase, the formation of the transient configurationmore » is triggered by the excitation of electrons into the bonding a 1g orbital, and is then stabilized by a lattice distortion characterized by a marked hardening of the A 1g coherent phonon. Furthermore, this configuration is in stark contrast with the thermally accessible ones - the A 1g phonon frequency actually softens when heating the material. Our results show the importance of selective electron-lattice interplay for the ultrafast control of material parameters, and are of particular relevance for the optical manipulation of strongly correlated systems, whose electronic and structural properties are often strongly intertwinned.« less
  • © The Author(s) 2017. The study of photoexcited strongly correlated materials is attracting growing interest since their rich phase diagram often translates into an equally rich out-of-equilibrium behaviour. With femtosecond optical pulses, electronic and lattice degrees of freedom can be transiently decoupled, giving the opportunity of stabilizing new states inaccessible by quasi-adiabatic pathways. Here we show that the prototype Mott-Hubbard material V 2 O 3 presents a transient non-thermal phase developing immediately after ultrafast photoexcitation and lasting few picoseconds. For both the insulating and the metallic phase, the formation of the transient configuration is triggered by the excitation of electronsmore » into the bonding a 1g orbital, and is then stabilized by a lattice distortion characterized by a hardening of the A 1g coherent phonon, in stark contrast with the softening observed upon heating. Our results show the importance of selective electron-lattice interplay for the ultrafast control of material parameters, and are relevant for the optical manipulation of strongly correlated systems.« less
  • We introduce a new scenario for heavy ion collisions that could solve the lingering problems associated with the so-called Hanbury Brown-Twiss (HBT) puzzle. We postulate that the system starts expansion as the perfect quark-gluon fluid but close to freeze-out it splits into clusters, due to a sharp rise of bulk viscosity in the vicinity of the hadronization transition. We then argue that the characteristic cluster size is determined by the viscosity coefficient and the expansion rate. Typically it is much smaller and at most weakly dependent of the total system volume (hence reaction energy and multiplicity). These clusters maintain themore » pre-existing outward-going flow, as a spray of droplets, but develop no flow of their own, and hadronize by evaporation. We provide an ansatz for converting the hydrodynamic output into clusters.« less