The influence of magnetised electron transport on thermal self-focusing and channelling of nanosecond laser beams

摘要

ThepropagationofananosecondIRlaserpulsethroughanunder-dense(0.01—0.1ncr)magnetisedlaser-plasmaisconsidered.Theinterplaybetweenmagnetisedtransport,B-fieldevolutionandplasmahydrodynamicsinthepresenceofadynamicallyevolvingbeamareinvestigatedbymeansofaparaxialwavesolvingmodulecoupledtoCTC,a2DMHDcodeincludingBraginskiielectrontransportandIMPACT,a2DimplicitVlasov-Fokker-Planck(VFP)codewithmagneticfields.MagneticfieldshavepreviouslybeenshowntoimprovedensitychannelformationforplasmawaveguideshoweverfluidsimulationspresentedhereindicatethatNernstadvectioncanresultintherapidcavitationofmagneticfieldinthelaser-heatedregionresultinginbeamdefocusing.Kineticsimulationsindicatethatstrongnon-localtransportispresentleadingtothefluidcodeoverestimatingheat-flowandmagneticfieldadvectionandresultingintherecoveryofbeamchannellingfortheconditionsconsidered...