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简介：Magneticreconnectionisthemostfundamentalenergy-transfermechanismintheuniversethatconvertsmagneticenergyintoheatandkineticenergyofchargedparticles.Forreconnectiontooccur,thefrozen-inconditionmustbreakdowninalocalizedregion,commonlycalledthe‘diffusionregion’.InEarth’smagnetosphere,iondiffusionregionshavealreadybeenobserved,whileelectrondiffusionregionshavenotbeendetectedduetotheirsmallscales(oftheorderofafewkm)(Paschmann,2008).Inthispaperwereport,forthefirsttime,insituobservationsofanactiveelectrondiffusionregionbythefourClusterspacecraftattheEarth’shighlatitudemagnetopause.Theelectrondiffusionregionischaracterizedbynongyrotropicelectrondistribution,strongfield-alignedcurrentscarriedbyelectronsandbi-directionalsuper-Alfvénicelectronjets.Alsoobservedweremultiplemicro-scalefluxropes,withascalesizeofabout5c/ωpe(12km,withc/ωpetheelectroninertiallength),thatarecrucialforelectronaccelerationintheguide-fieldreconnectionprocess(Drakeetal.,2006a).Thedatademonstratetheexistenceoftheelectrondiffusionregionincollisionlessguide-fieldreconnectionatthemagnetopause.

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简介：AnewcombinedFermi,betatron,andturbulentelectronaccelerationmechanismisproposedininteractionofmagneticislandsduringturbulentmagneticreconnectionevolutioninexplosiveastrophysicalphenomenaatlargetemporal-spatialscale(LTSTMR),theratioofobservedcurrentsheetsthicknesstoelectroncharacteristiclength,electronLarmorradiusforlow-βandelectroninertiallengthforhigh-β,isontheorderof10^10–10^11;theratioofobservedevolutiontimetoelectrongyroperiodisontheorderof10^7–10^9).Theoriginalcombinedaccelerationmodelisknowntobeoneofgreatestimportanceintheinteractionofmagneticislands;itassumesthatthecontinuouskinetic-dynamictemporal-spatialscaleevolutionoccursastwoseparateindependentprocesses.Inthispaper,wereconsiderthecombinedaccelerationmechanismbyintroducingakinetic-dynamic-hydrofull-coupledmodelinsteadoftheoriginalmicro-kineticormacro-dynamicmodel.Weinvestigatedifferentaccelerationmechanismsinthevicinityofneutralpointsinmagneticislandsevolution,fromthestageofshrinkandbreakupintosmallerislands(kineticscale),tothestageofcoalescenceandgrowthintolargerislands(dynamicscale),tothestagesofconstantandquasi-constant(contracting-expanding)islands(hydroscale).Asaresult,wegiveforthefirsttimetheaccelerationefficienciesofdifferenttypesofaccelerationmechanismsinmagneticislands’interactionsinsolaratmosphereLTSTMRactivities(pico-,10^–2–10^5m;nano-,10^5–10^6m;micro-,10^6–10^7m;macro-,10^7–10^8m;large-,10^8–10^9m).

简介：Whistler-modechoruswavesareregardedasanimportantaccelerationmechanismcontributingtotheformationofrelativisticandultra-relativisticelectronsintheJovianradiationbelts.QuantitativedeterminationofthechoruswavedrivenelectronscatteringeffectintheJovianmagnetosphererequiresdetailedinformationofbothambientmagneticfieldandplasmadensityandwavespectralproperty,whichhowevercannotbealwaysreadilyacquiredfromobservationsofexistedmissionstoJupiter.WethereforeperformacomprehensiveanalysisofthesensitivityofchorusinducedelectronscatteringratestoambientmagnetosphericandwaveparametersintheJovianradiationbeltstoelaboratetowhichextentthediffusioncoefficientsdependonanumberofkeyinputparameters.Itisfoundthatquasi-linearelectronscatteringratesbychoruscanbestronglyaffectedbytheambientmagneticfieldintensity,thewavelatitudinalcoverage,andthepeakfrequencyandbandwidthofthewavespectraldistributionintheJovianmagnetosphere,whiletheyonlyrelyslightlyonthebackgroundplasmadensityprofileandthepeakwavenormalangle,especiallywhenthewaveemissionsareconfinedatlowerlatitudes.Giventhechoruswaveamplitude,chorusinducedelectronscatteringratesstronglydependonJovianL-shelltoexhibitatendencyapproximatelyproportionaltoLJ3.OurcomprehensiveanalysisexplicitlydemonstratestheimportanceofreliableinformationofboththeambientmagnetosphericstateandwavedistributionpropertytounderstandingthedynamicelectronevolutionintheJovianradiationbeltsandthereforehasimplicationsforfuturemissionplanningtoexploretheextremeparticleradiationenvironmentofJupiteranditssatellites.