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Title: Kinetics of the Collisionless Expansion of Spherical Nanoplasmas

Abstract

The collisionless expansion of spherical plasmas composed of cold ions and hot electrons is analyzed using a novel kinetic model, with special emphasis on the influence of the electron dynamics. Simple, general laws are found, relating the relevant expansion features to the initial conditions of the plasma, determined from a single dimensionless parameter. A transition is identified in the behavior of the ion energy spectrum, which is monotonic only for high electron temperatures, otherwise exhibiting a local peak far from the cutoff energy.

Authors:
; ; ;  [1];  [2]
  1. Dipartimento di Energetica, Politecnico di Torino, 10129 Turin (Italy)
  2. GoLP/Centro de Fisica dos Plasmas, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)
Publication Date:
OSTI Identifier:
20775229
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 96; Journal Issue: 17; Other Information: DOI: 10.1103/PhysRevLett.96.175002; (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; COLLISIONLESS PLASMA; ELECTRON TEMPERATURE; ELECTRONS; ENERGY SPECTRA; EXPANSION; KINETICS; SPHERICAL CONFIGURATION

Citation Formats

Peano, F., Peinetti, F., Mulas, R., Coppa, G., and Silva, L.O. Kinetics of the Collisionless Expansion of Spherical Nanoplasmas. United States: N. p., 2006. Web. doi:10.1103/PhysRevLett.96.175002.
Peano, F., Peinetti, F., Mulas, R., Coppa, G., & Silva, L.O. Kinetics of the Collisionless Expansion of Spherical Nanoplasmas. United States. doi:10.1103/PhysRevLett.96.175002.
Peano, F., Peinetti, F., Mulas, R., Coppa, G., and Silva, L.O. Fri . "Kinetics of the Collisionless Expansion of Spherical Nanoplasmas". United States. doi:10.1103/PhysRevLett.96.175002.
@article{osti_20775229,
title = {Kinetics of the Collisionless Expansion of Spherical Nanoplasmas},
author = {Peano, F. and Peinetti, F. and Mulas, R. and Coppa, G. and Silva, L.O.},
abstractNote = {The collisionless expansion of spherical plasmas composed of cold ions and hot electrons is analyzed using a novel kinetic model, with special emphasis on the influence of the electron dynamics. Simple, general laws are found, relating the relevant expansion features to the initial conditions of the plasma, determined from a single dimensionless parameter. A transition is identified in the behavior of the ion energy spectrum, which is monotonic only for high electron temperatures, otherwise exhibiting a local peak far from the cutoff energy.},
doi = {10.1103/PhysRevLett.96.175002},
journal = {Physical Review Letters},
number = 17,
volume = 96,
place = {United States},
year = {Fri May 05 00:00:00 EDT 2006},
month = {Fri May 05 00:00:00 EDT 2006}
}
  • The collisionless adiabatic expansion into vacuum of spherical plasma targets (clusters) composed of cold single- or multispecies ions and hot electrons is studied kinetically by numerical solving of the nonrelativistic equations of motion of plasma particles in the self-consistent electrostatic field. The expansion dynamics for the whole range of electron temperatures from much less than to much higher than the cluster Coulomb energy is described for various initial plasma density profiles and cluster structures. The explosion of two ion species heterogeneous (layered) and homogeneously mixed targets is studied in detail for the wide range of light ion concentration and kinematicmore » parameter.« less
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  • The expansion of laser-irradiated clusters can be controlled by acting on the amount of energy delivered to the electrons. When increasing the electron energy, the expansion regime varies smoothly from a quasineutral, hydrodinamic-like to a Coulomb explosion (CE), as revealed by self-consistent kinetic analysis. A double-pump irradiation scheme can produce hybrid expansion regimes wherein a slow hydrodynamic expansion is followed by a fast CE, leading to ion overtaking and producing multiple ion flows expanding with different velocities, which can lead to intracluster fusion reactions in homonuclear deuterium clusters.
  • We study the x-ray L-shell production from large krypton clusters submitted to ultrashort and intense laser pulses. The x-ray photon emission pattern appears to be isotropic and the absolute x-ray photon yields per laser pulse are measured as a function of the laser intensity and of the estimated mean cluster size in the supersonic expansion. In particular, up to 4{times}10{sup 6} x-ray photons per laser shot are detected at intensities approaching 5{times}10{sup 17} Wthinspcm{sup {minus}2}. This allows us to determine precisely a maximum conversion efficiency of 1.7{times}10{sup {minus}8} between the incoming IR photon and the generated x-ray photon energies. Finally,more » the x-ray photon emission is understood as the result of highly stripped ion production with L-shell electron-impact ionization and excitation in laser-heated cluster-sized nanoplasmas. {copyright} {ital 1997} {ital The American Physical Society}« less