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Title: Dynamics and structure of self-generated magnetics fields on solids following high contrast, high intensity laser irradiation

The dynamics of self-generated magnetic B-fields produced following the interaction of a high contrast, high intensity (I > 10{sup 19 }W cm{sup −2}) laser beam with thin (3 μm thick) solid (Al or Au) targets is investigated experimentally and numerically. Two main sources drive the growth of B-fields on the target surfaces. B-fields are first driven by laser-generated hot electron currents that relax over ∼10–20 ps. Over longer timescales, the hydrodynamic expansion of the bulk of the target into vacuum also generates B-field induced by non-collinear gradients of density and temperature. The laser irradiation of the target front side strongly localizes the energy deposition at the target front, in contrast to the target rear side, which is heated by fast electrons over a much larger area. This induces an asymmetry in the hydrodynamic expansion between the front and rear target surfaces, and consequently the associated B-fields are found strongly asymmetric. The sole long-lasting (>30 ps) B-fields are the ones growing on the target front surface, where they remain of extremely high strength (∼8–10 MG). These B-fields have been recently put by us in practical use for focusing laser-accelerated protons [B. Albertazzi et al., Rev. Sci. Instrum. 86, 043502 (2015)]; here we analyze in detail theirmore » dynamics and structure.« less
Authors:
 [1] ;  [2] ;  [3] ; ;  [1] ;  [4] ;  [5] ;  [6] ; ; ;  [7] ;  [8] ; ; ; ; ;  [9] ; ; ;  [1] more »;  [10] ;  [11] ;  [12] ;  [13] ; « less
  1. LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France)
  2. (Canada)
  3. (Japan)
  4. (Russian Federation)
  5. INRS-EMT, 1650 bd L. Boulet, J3X1S2, Varennes, Québec (Canada)
  6. (Italy)
  7. Institut für Laser-und Plasmaphysik, Heinrich-Heine-Universität, Düsseldorf (Germany)
  8. School of Mathematics and Physics, The Queen's University, Belfast (United Kingdom)
  9. CELIA, University of Bordeaux - CNRS - CEA, 33405 Talence (France)
  10. Dept. SBAI, Universita di Roma “La Sapienza,” Via A. Scarpa 14, 00161 Rome (Italy)
  11. LLNL, East Av., Livermore, California 94550 (United States)
  12. Department of Physics, University of Nevada, Reno, Nevada 89557-0058 (United States)
  13. Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation)
Publication Date:
OSTI Identifier:
22489952
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 12; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ASYMMETRY; DENSITY; ELECTRONS; ENERGY ABSORPTION; FOCUSING; LASER RADIATION; MAGNETIC FIELDS; PHOTON BEAMS; PROTONS; SOLIDS; SURFACES; TEMPERATURE GRADIENTS