Rapid self-magnetization of laser speckles in plasmas by nonlinear anisotropic instability

Presented here are the first kinetic two-dimensional Vlasov- Fokker-Planck calculations of inertial confinement fusion-related laser-plasma interactions, to include self-consistent magnetic fields, hydrodynamic plasma expansion and anisotropic electron pressure. An underdense plasma, reminiscent of...

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Main Authors: Thomas, A, Kingham, R, Ridgers, C
Format: Journal article
Language:English
Published: 2009
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author Thomas, A
Kingham, R
Ridgers, C
author_facet Thomas, A
Kingham, R
Ridgers, C
author_sort Thomas, A
collection OXFORD
description Presented here are the first kinetic two-dimensional Vlasov- Fokker-Planck calculations of inertial confinement fusion-related laser-plasma interactions, to include self-consistent magnetic fields, hydrodynamic plasma expansion and anisotropic electron pressure. An underdense plasma, reminiscent of the gas fill of a hohlraum, is heated by a laser speckle with Iλ2 = 1.0 x 1015 W cm-2μm2 and radius w0 = 5 μm. Inverse bremsstrahlung absorption of the laser and non-local electron transport lead to the development of a collisional analogue of the Weibel electromagnetic instability. The instability is seeded by magnetic fields, generated in an initial period of linear growth due to the anisotropic electron distribution arising in a laser speckle. Using the circular polarization does not generate significant fields. For linear polarization, the field generally saturates when the magnetization is ωτei > 1, and the effective growth rate is similar to the coherence time of typical laser speckles. The presence of these magnetic fluctuations significantly affects the heat fluxes and hydrodynamics in the plasma. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
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spelling oxford-uuid:7d1d61cb-1606-4762-b56c-eac2f26072312022-03-26T21:01:19ZRapid self-magnetization of laser speckles in plasmas by nonlinear anisotropic instabilityJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:7d1d61cb-1606-4762-b56c-eac2f2607231EnglishSymplectic Elements at Oxford2009Thomas, AKingham, RRidgers, CPresented here are the first kinetic two-dimensional Vlasov- Fokker-Planck calculations of inertial confinement fusion-related laser-plasma interactions, to include self-consistent magnetic fields, hydrodynamic plasma expansion and anisotropic electron pressure. An underdense plasma, reminiscent of the gas fill of a hohlraum, is heated by a laser speckle with Iλ2 = 1.0 x 1015 W cm-2μm2 and radius w0 = 5 μm. Inverse bremsstrahlung absorption of the laser and non-local electron transport lead to the development of a collisional analogue of the Weibel electromagnetic instability. The instability is seeded by magnetic fields, generated in an initial period of linear growth due to the anisotropic electron distribution arising in a laser speckle. Using the circular polarization does not generate significant fields. For linear polarization, the field generally saturates when the magnetization is ωτei > 1, and the effective growth rate is similar to the coherence time of typical laser speckles. The presence of these magnetic fluctuations significantly affects the heat fluxes and hydrodynamics in the plasma. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
spellingShingle Thomas, A
Kingham, R
Ridgers, C
Rapid self-magnetization of laser speckles in plasmas by nonlinear anisotropic instability
title Rapid self-magnetization of laser speckles in plasmas by nonlinear anisotropic instability
title_full Rapid self-magnetization of laser speckles in plasmas by nonlinear anisotropic instability
title_fullStr Rapid self-magnetization of laser speckles in plasmas by nonlinear anisotropic instability
title_full_unstemmed Rapid self-magnetization of laser speckles in plasmas by nonlinear anisotropic instability
title_short Rapid self-magnetization of laser speckles in plasmas by nonlinear anisotropic instability
title_sort rapid self magnetization of laser speckles in plasmas by nonlinear anisotropic instability
work_keys_str_mv AT thomasa rapidselfmagnetizationoflaserspecklesinplasmasbynonlinearanisotropicinstability
AT kinghamr rapidselfmagnetizationoflaserspecklesinplasmasbynonlinearanisotropicinstability
AT ridgersc rapidselfmagnetizationoflaserspecklesinplasmasbynonlinearanisotropicinstability