自由电子束与相向传播的两束激光作用的经典理论计算

自由电子束与相向传播的两束激光作用的经典理论计算ClassicalInterpretationoftheInteractionbetweenanElectronBeamandTwoCounter-propagatingLaserBeams司徒树平张征文李毓增中山大学理工学院2007年8月延边Outline•Introduction•LabPrototype•MotionEquation•CalculationandInterpretation•SummaryIntroduction•Muchadvancedresearchhasbeenconductedrecentlyontheinteractionbetweenelectronandcoherentradiations(Kapitza-Diraceffect,free-electronlaser,….)•Electroninteractingwithtwocounter-propagatingcoherentradiationsisthecommonmodel•NonrelativisticelectroninteractingwithcoherentwaveisgovernedbyLorentzforceequation•OneofthevaluableproblemistounlocktheenergychangeoftheelectronLabPrototypeConceptualdiagramfortheExperimentofinteractionbetweenelectronsandtwoCounter-propagatingLaserBeamsRelevantexperiment•CollectorcurrentsignalvsinitialelectronenergyMotionEquation()ssssssBnEEEsEsBnLaser:)()]([][acwskwsacwsEEEecEecdtEdBBEEEeBEedtpdElectricForceandLorentzForce:02sin222dTdMotionEquation02sin222dTdWhere00(,,,;,,,,)wscmeP0(,,;,,,)acwsemcE,2TLet:0sin22ddCalculationandInterpretation•Solvinganonlineardifferentialequation•Runge-Kuttaarithmetic•Adomianpolynomial02(cos/)ndd(,)dyfxydx0ˆˆˆuNuRuLuNLuRLuLLuˆˆˆˆˆˆ1110ˆnnAuNWhere:CalculationandInterpretation•PhaseCurve•Accelerating•DeceleratingCalculationandInterpretation•FinalEnergyDistribution•Accelerating•Decelerating•Finalelectronenergydistributionfordifferentinitialenergy(deceleration)CalculationandInterpretation•QualitativeAnalysis•Accelerating•DeceleratingSummary•Theapplicationofaxialelectricfieldcausestothetrappingoftheelectron.•Thetheoreticalcalculationsarefoundtobeconsistentwithexperimentalmeasurements.•Themechanismreliesonnonlinearinteractionwhichcausesthephasebunchingthatduetothebreakingofuniformdistributionofelectronenergy.•Classicalelectrodynamicscanwellexplainedtheinteractionoffree-electronwithcoherentradiations.Thankyou!