Observation and modelling of stimulated Raman scattering driven by an optically smoothed laser beam in experimental conditions relevant for shock ignition

作     者：G.Cristoforetti S.Hüller P.Koester L.Antonelli S.Atzeni F.Baffigi D.Batani C.Baird N.Booth M.Galimberti K.Glize A.Héron M.Khan P.Loiseau D.Mancelli M.Notley P.Oliveira O.Renner M.Smid A.Schiavi G.Tran N.C.Woolsey L.A.Gizzi 

作者机构：Intense Laser Irradiation LaboratoryINO-CNRINO-CNR56124 PisaItaly Centre de Physique Théorique CPHTCNRSIP ParisEcole Polytechnique91128 PalaiseauFrance York Plasma InstituteDepartment of PhysicsUniversity of YorkYork YO105DDUK Dipartimento SBAIUniversitàdi Roma'La Sapienza'00161 RomaItaly Universitéde BordeauxCNRSCEACELIA33405 TalenceFrance STFC Rutherford Appleton LabCentral Laser FacilityDidcot SN21SZUK Key Laboratory for Laser Plasmas(MOE)Shanghai Jiao Tong UniversityShanghai 200240China CEADAMDIF91297 ArpajonFrance UniversitéParis-SaclayCEALMCE91680 Bruyeres-le-ChatelFrance Institute of PhysicsELI BeamlinesInstitute of Plasma PhysicsCzech Academy of Sciences18221 PragueCzech Republic Helmholtz-Zentrum Dresden-Rossendorf01328 DresdenGermany 

出 版 物：《High Power Laser Science and Engineering》 (高功率激光科学与工程（英文版）)

年 卷 期：2021年第9卷第4期

页      面：160-178页

核心收录：

学科分类：08[工学] 0827[工学-核科学与技术] 082701[工学-核能科学与工程] 0702[理学-物理学] 

基　　金：financial support from the LASERLAB-EUROPE Access to Research Infrastructure activity within the EC’s seventh Framework Program(Application No.18110033) carried out within the framework of the EUROfusion Enabling research projects AWP19-20-ENR-IFE19.CEA01 and AWP21-ENR-01-CEA-02 funding from the Euratom research and training programme 20192020 and 2021-2025 under grant No.633053 financial support from the CNR-funded Italian research Network ELI-Italy(D.M.No.63108.08.2016) the Czech Ministry of Education,Youth and Sports,project LTT17015。 

主　　题：plasma simulations shock ignition stimulated Raman scattering inertial confinement fusion laser-plasma interaction 

摘      要：We report results and modelling of an experiment performed at the Target Area West Vulcan laser facility,aimed at investigating laser±plasma interaction in conditions that are of interest for the shock ignition scheme in inertial confinement fusion(ICF),that is,laser intensity higher than 10^(16) W/cm^(2) impinging on a hot(T1 keV),inhomogeneous and long scalelength pre-formed plasma.Measurements show a significant stimulated Raman scattering(SRS)backscattering(;%-20%of laser energy)driven at low plasma densities and no signatures of two-plasmon decay(TPD)/SRS driven at the quarter critical density region.Results are satisfactorily reproduced by an analytical model accounting for the convective SRS growth in independent laser speckles,in conditions where the reflectivity is dominated by the contribution from the most intense speckles,where SRS becomes saturated.Analytical and kinetic simulations well reproduce the onset of SRS at low plasma densities in a regime strongly affected by non-linear Landau damping and by filamentation of the most intense laser speckles.The absence of TPD/SRS at higher densities is explained by pump depletion and plasma smoothing driven by filamentation.The prevalence of laser coupling in the low-density profile justifies the low temperature measured for hot electrons(7-12 keV),which is well reproduced by numerical simulations.