简介:Atheoreticalinvestigationiscarriedouttostudytheexistence,formationandbasicpropertiesofionacoustic(IA)doublelayers(DLs)inamagnetizedbi-ionplasmaconsistingofwarm/coldionsandBoltzmanndistributedelectrons.Basedonthereductiveperturbationtechnique,anextendedKortewegde-Vries(KdV)equationisderived.Thepropagationoftwopossiblemodes(fastandslow),andtheirevolutionareinvestigated.Theeffectsofobhqueness,magnitudeofthemagneticfield,ionconcentration,polarityofions,andiontemperatureontheIADLprofileareanalyzed,andthentherangesofparametersforwhichtheIADLsexistareinvestigatedindetails.
简介:在哪儿在核物理学研究触发了一个新时代,在铁以外的重元素什么时候,并且怎么充实我们的宇宙的待研究的问题。所有相关核物理学输入,很充满中子的核种的团是为在铁以外揭示重元素的起源的关键数量。尽管这个性质的精确决心是大挑战,庞大的进步在最近的十年被取得了,并且它显著地作出贡献到原子结构和天体物理学的nucleosynthesis研究。在这评论,我们首先调查我们原子集体表面的现在的知识,强调在r过程计算的原子集体精确的重要性。我们然后与一些选择例子在原子集体测量的各种各样的方法讨论最近的进步。为每个方法,我们集中于最近的突破并且讨论改进称r过程核种的可能的方法。
简介:Recentlytherehasbeengreatprogressinlaser-drivenplasma-basedacceleratorsbyexploitinghigh-powerlasers,whereelectronbeamscanbeacceleratedtomulti-GeVenergyinacentimeter-scaleplasmaduetothelaserwakefieldaccelerationmechanism.While,todate,worldwideresearchonlaserplasmaacceleratorshasbeenfocusedonthecreationofcompactparticleandradiationsourcesforbasicsciences,medicalandindustrialapplications,thereisgreatinterestinapplicationsforhigh-energyphysicsandastrophysics,exploringunprecedentedhigh-energyfrontierphenomena.Inthiscontext,wepresentanoverviewofexperimentalachievementsinlaserplasmaaccelerationfromtheperspectiveoftheproductionofGeV-levelelectronbeams,anddeducethescalingformulascapableofpredictingexperimentalresultsself-consistently,takingintoaccountthepropagationofarelativisticlaserpulsethroughplasmaandtheacceleratingfieldreductionduetobeamloading.Finally,wepresentdesignexamplesfor10-GeV-levellaserplasmaacceleration,whichisexpectedinnear-termexperimentsbymeansofpetawatt-classlasers.
简介:CO2methanationhasbeenahottopicbecauseofitsimportantapplicationinthespacecraftandpotentialutilizationofcarbondioxide.Nickelcatalystisactiveforthisreaction.However,itsactivitystillneedstobeimproved.Dielectricbarrierdischarge(DBD)plasma,initiatedatambientconditionandoperatedat~150°C,hasbeenemployedinthisworkfordecompositionofnickelprecursortoprepareNi/MgAl2O4.Theplasmadecompositionresultsinhighdispersion,uniquestructure,enhancedreducibilityofNiparticlesandpromotedcatalyst-supportinteraction.AnimprovedactivityofCO2methanationwithahigheryieldofmethanehasbeenachievedovertheplasmadecomposedcatalyst,comparedtothecatalystpreparedthermally.Forexample,themethaneyieldoftheplasmapreparedcatalystis71.8%at300°Cbutitis62.9%overthethermalpreparedcatalyst.ThecatalystcharacterizationconfirmedthatCO2methanationovertheDBDplasmapreparedcatalystfollowspathwayofCOmethanation.
简介:Thedispersionpropertiesofhigh-andlow-frequencyelectrostaticoscillationsofasphericalmetallicplasmaconsistingofhotelectronsandcoldionsareinvestigated.Themaininterestandthekeyfirstapplicationsofthissystemarethesphericalmetalnanoparticles.Generalexpressionsofdispersionrelationsareobtainedfortheso-calledsurfaceandbulkplasmonwaves,andsurfaceandbulkion-acousticwavesinsphericalgeometry,usinghydrodynamicequationsandPoissonequationwithappropriateboundaryconditions.Numericalresultsshowthatdispersioneffectsbecomelargeformetallicparticlesofsmallradii,particularlyintherangeoffewnanometers.
简介:在同一直线上的双脉搏的导致激光的故障光谱学被使用一双毫微秒Nd在Si水晶上执行:在1064nm射出的钇铝柘榴石激光来源。光谱紧张和选择Si原子、离子的线的signalto-噪音比率被用来评估光排放。当改变interpulse延期时间和二的精力比率时,光排放紧张被记录搏动的激光。线紧张和signal-to-noise比率上的数据获得延期时间的效果也被调查了。基于结果,最佳的interpulse延期时间,二的精力比率搏动了激光,和完成原子、离子的最大值的数据获得延期时间衬里紧张被作出对有利的裁决有在同一直线上的双脉搏的激光途径的Si血浆的产生。为观察的线紧张变化的主导的机制也被讨论。另外,在不同的门的血浆温度和电子数字密度推迟时间和不同interpulse延期时间被导出。血浆在更短的interpulse延期时间在电子温度和电子数字密度上防护的重要影响被观察。
简介:Adischarge-produced-plasma(DPP)sourceemittingintheextremeultraviolet(EUV)spectralregionisrunningattheENEAFrascatiResearchCentre.Theplasmaisgeneratedinlow-pressurexenongasandefficientlyemits100-nsdurationradiationpulsesinthe10–20-nmwavelengthrange,withanenergyof20mJ/shot/srata10-Hzrepetitionrate.Thecomplexdischargeevolutionisconstantlyexaminedandcontrolledwithelectricalmeasurements,whileansgatedCCDcameraallowedobservationofthedischargedevelopmentinthevisible,detectionoftime-resolvedplasmacolumnpinching,andoptimizationofthepre-ionizationtiming.AccuratelycalibratedZr-filteredPINdiodesareusedtomonitorthetemporalbehaviourandenergyemissionoftheEUVpulses,whilethecalibrationofadosimetricfilmallowsquantitativeimagingoftheemittedradiation.Thiscomprehensiveplasmadiagnosticshasdemonstrateditseffectivenessinsuitablyadjustingthesourceconfigurationforseveralapplications,suchasexposuresofphotonicmaterialsandinnovativephotoresists.
简介:ThepropagationofquadrupleGaussianlaserbeaminaplasmacharacterizedbyaxialinhomogeneityandnonlinearityduetoponderomotiveforceintheparaxialrayapproximationisinvestigated.Anappropriateexpressionforthenonlineardielectricconstanthasbeendevelopedinthepresenceofexternalmagneticfield,withlinearabsorptionandduetosaturationeffectsforarbitrarylargeintensity.Theeffectsofdifferenttypesofplasmaaxialinhomogeneitiesonself-focusingoflaserbeamhavebeenstudiedwiththetypicallaserandplasmaparameters.Self-focusingofquadrupleGaussianlaserbeaminthepresenceofexternallyappliedmagneticfieldandsaturatingparameterisfoundsignificantlyimprovedinthecaseofextraordinarymode.Ourresultsrevealthatinitiallyconvergingbeamshowsoscillatoryconvergencewhereasinitiallydivergingbeamshowsoscillatorydivergence.Thebeamismorefocussedatlowerintensityinbothcasesviz.extraordinaryandordinarymode.