Theco-existenceoftheRamanandBrillouinbackscatteringinstabilityisanimportantissueforinertialconfinementfusion.Thepresentpaperpresentsextensiveone-dimensional（1D）particle-in-cell（PIC）simulationsforawiderangeofparametersextendingandcomplementingpreviousfindings.PICsimulationsshowthatthescenarioofreflectivityevolutionandsaturationisverysensitivetothetemperatures,intensities,sizeofplasmaandboundaryconditionsemployed.TheLangmuirdecayinstabilityisobservedforrathersmallkepwλDbuthasnoinfluenceonthesaturationofBrillouinbackscattering,althoughthereisaclearcorrelationofLangmuirdecayinstabilitymodesandion-fractionaldecayforcertainparameterranges.Ramanbackscatteringappearsatanyintensityandtemperaturebutisonlyatransientphenomenon.InseveralconfigurationsforwardaswellasbackwardRamanscatteringisobserved.Fortheintensitiesconsidered,Iλo2above1015Wμm2/cm2,Ramanisalwaysofburstynature.Aparticularsetupallowsthesimulationofmulti-speckleaspectsinwhichcaseitisfoundthatRamanisself-limitingduetostrongmodificationsofthedistributionfunction.KineticeffectsareofprimeimportanceforRamanbackscatteringathightemperatures.NouniquescenarioforthesaturationofRamanscatteringorRaman–Brillouincompetitiondoesexist.ThemaineffectintheconsideredparameterrangeispumpdepletionbecauseoflargeBrillouinbackscattering.However,inthelowkepwλDregimethepresenceofion-acousticwavesduetotheLangmuirdecayinstabilityfromtheRamancreatedelectronplasmawavescanseedtheion-fractionaldecayandaffecttheBrillouinsaturation.
