学科分类
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500 个结果
  • 简介:Characteristicsofiontemperaturemeasuredwithcharge-exchangerecombinationspectroscopy(CXRS)werestudiedinOhmic,lower-hybrid-wave(LHW)drivenandion-cyclotron-resonance-frequency(ICRF)heatedplasmasinHT-7.TheresultsindicatethatthecentraliontemperatureTi0followstheone-thirdpowerlawintheproductofcentralline-averageddensityneandplasmacurrentIpinOhmicdischargesandisthereforeconsistentwiththeArtsimovichscalinglawTi0=K·(Ip·Bt·ne·R2)1/3.ItisshownthatthereisanappreciableincreaseofiontemperatureduringtheoperationwithbothLHWandICRFandthattheincrementofiontemperatureinthoseshotsismainlyduetotheenergytransferviacollisionsbetweenionsandelectronsratherthatbydirectheatingoftheions.

  • 标签: 热等离子体 温度特性 托卡马克 回旋共振频率 离子温度 等离子体电流
  • 简介:SawtoothcontrolexperimentswereperformedonHT-7withalimiterconfigurationandontheExperimentalAdvancedSuperconductingTokamak(EAST)withadoublenullcon-figuration.Thesawtoothperiodcanbemodifiedbylowerhybridwave(LHW)andioncyclotronresonancefrequency(ICRF).Differentsawtoothbehaviorwasobservedwiththesameplasmadensity,LHWpowerbutdifferentplasmacurrentsonHT-7.TherewasadwelltimebetweenLHWaddedandthesawtoothstabilizationonHT-7whilethesawtoothstabilizationimmediatelyhappenedwhenLHWpowerwasinjectedonEAST.Thepossiblemechanismofthesawtoothcontrolisdiscussedinthispaper.Alltheexperimentalresultshaveprovedthatpowerdepositionoftheradiofrequency(RF)shouldbethekeyfactorforsawtoothcontrol.

  • 标签: 超导托卡马克 控制实验 HT-7 锯齿 EAST 等离子体密度
  • 简介:Experimentsonlowerhybridwave(LHW)couplingwereinvestigatedintheHT-7tokamak.GoodcouplingofLHWplasmahasbeendemonstratedatdifferentconditionsintheHT-7tokamak.RelevantresultshaveprovedthatLHW-plasmacouplingisaffectedbythephasedifferencebetweenadjacentwaveguides.Furthermore,theedgedensityaroundthegrillandrelevantcouplingcanbeadjustedbychangingtheplasmalineaveragedensityorthegapvaluebetweentheLHgrillandthelastclosedfluxsurfaces(LCFS).ItisfoundthatthecouplingofLHWsbecomespoorwhentheedgedensityaroundtheLHgrillislargeenoughintheHT-7tokamak,andthatcouplingremainsgoodwithaproperedgedensity.WithincreasingLHWpower,itisalsofoundthatthereflectioncoefficients(RCs)increaseduetonon-lineareffectsunderconditionsoflowedgerecycling,butcandecreaseunderhighedgerecycling.Theedgedensitydependsmainlyonthecompetitionbetweentheponderomotiveforce(PMF)andtheedgerecyclingintensityintheHT-7tokamak.

  • 标签: HT-7托卡马克 低混杂波 波耦合 实验 等离子体 边缘密度
  • 简介:SawtoothactivityonHT-7tokamakhasbeeninvestigatedexperimentallymainlybyusingsoftx-raydiodearrayandmagneticprobes.Theirbehaviorsandoccurrencesarecorrelatedcloselytothedischargeconditions:theelectrondensityNe,theelectrontemperatureTe,thesafetyfactorqaonplasmaboundaryandwallconditionetc.Whencentralline-averagedelectrondensityNe(0)isover2.0×1013cm-3,majorsawtoothactivityemergeswithaperiodofupto6.5msandafluctuationamplitudeofupto2~30%ofSXRradiationsignal.Insomecasessuchasthesafetyfactorbetween4.2~4.7andZeff=3.0~6.0,amonstersawtoothactivityoftenemergeswithoutapparentdeteriorationofplasmaconfinementandwithoutmajordisruption.Duringtheseevents,abundantMHDphenomenaareobservedincludingpartialsawtoothoscillations.Inthispaper,theobservedsawtoothbehaviorsandtheirdependenceontheandtheirdependencedensityNeandwallconditioninohmicallyheatedplasmaareintroduced,theresultsarediscussedandpresented.

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  • 简介:TheICRF(IonCyclotronRangeFrequency)cleaningtechniquehasbeenusedasaroutinewallcleaningmethodintheHT-7superconductingtokamak.Inawiderangeoftoroidalfield,thcremovalrateofresidualgasbyICRFcleaningwasabouttwentytimeshigherthanthatofglowdischargecleaning(GDC).AtdifferentgaspressureandRFpowerlevels,theICRFcleaningisstudiedcarcfully.Agoodimpurityclcaningeffectandaveryhighhydrogenremovalratewereobtained.Theremovalrateofhydrogenby5kWICRFcleaningachievedwas1.6×10-5Torr.1/s.AndtherelationshipsamongpressureP,outgassingrateQ,atomiclayersLabsorbedonsurfaceandthecleaningmodewerediscussedbriefly.

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  • 简介:Thispaperreportsforthefirsttimeanexperimentalstudyonthepowerdepositionprofileoftheioncyclotronrangefrequencies(ICRF)powerdepositingonelectronsinHT-7.ThefastFouriertransform(FFT)analysisandthebreakinslope(BIS)methodareutilizedtoobtaintheinformationofthepowerdeposition.Theresultsindicatethattheelectronswereheateddirectly,andtheelectronsabsorbedaround20%oftheinputpowerofthedischargeofinterest.

  • 标签: 功率沉积 实验测定 HT-7 ICRF 电子 快速傅立叶变换
  • 简介:DedicatedexperimentsintheHT-7tokamakwereperformedtoinvestigatethein-fluenceoferosionanddepositiononthemirrorsamples.Thefirstmirror(FM)samplesmadeofpolycrystalline(PC)stainlesssteel(SS),molybdenum(Mo)andtungsten(W)werefixedonaholderatanangleof45withrespecttothehorizontalplaneandsetatdifferentlocationswithdifferentconnectionlengthsalongthemagneticfield.Theopticalreflectivityofthefirstmirrorwasmeasuredbyaspectrophotometerbeforeandafterplasmaexposure.Itwasfoundthatthesurfacemorphologyandspecularreflectivityofthemirrorsamplesaftertheexposureweredifferentwithrespecttothedifferentdistancesfromthemirrorsurfacetothelastclosedfluxsurface(LCFS)oftheplasmainthetokamak.Itwasalsofoundthatshorteningtheconnectionlengthbeforethemirrorsurfacewouldweakentheinfluenceoftheplasmaerosionandimpuritydepositiononthemirrorsurface.Inordertomaintaintheopticalcharacteristicsofthemirrorsurface,itisnecessarytoadoptthein-situcleaningandmirrorprotectiontechniques.

  • 标签: HT-7托卡马克装置 杂质沉积 侵蚀 镜子 表面形貌 金属
  • 简介:Inlowerhybridcurrentdrive(LHCD)experimentsinHT-7,LHwavecoupledtotheplasmafrom12klystronsislaunchedbyaphasedmulti-junctiongrill.Highpowermicrowavereflectionorarc,whichthreatenstheklystrons,thewave-guideceramicwindowsandthevacuumofthetokamak,occursometimesduringtheexperiments.Forthesakeofsafety,ahighpowermicrowavetestsystemtoperformsimulationswasdeveloped.Inthetestexperiments,theklystronandwindowcanbewellprotectedwithanoptimizedmicrowavemonitorandaPINswitch.ThelayoutofthetestsystemandthesimulatedexperimentsforHT-7aredescribedinthispaper.

  • 标签: 真空 微波监视器 低杂波电流驱动 汽车防盗器开关
  • 简介:APlasmaSurfaceInteraction(PSI)experimentonChinaLowActivationMarten-sitic(CLAM)steelwasdonetocheckifCLAMsteelcouldbeusedasaPlasmaFacingMaterial(PFM).Aspecimenwithadiameterof45mmwasexposedto897shotsofdeuteriumplasmaswithatotaldurationof712secataminorradiusof30cminHT-7tokamak.Duringtheexpo-sureexperiment,noobservableinfluencewasfoundonplasmaperformance.Afterexposure,thesurfaceofthespecimenseemedassmoothasbeforebutwithsomecolourchangeatthemarginofthespecimen.Eventhoughsomemicro-damage,suchasdenseblisters,melting,splashing,depositions,anddust,wasfoundonlocalsurfaceswithScanningElectronMicroscopic(SEM)observation.Thereflectivityofthespecimendecreasedonlyslightly.AlloftheseshowsCLAMsteelhasgoodstabilityandirradiationresistance.Withfurtheroptimization,itcouldpossiblybeusedasthefirstmirrormaterialforplasmadiagnosticsintokamaks.

  • 标签: 中国低活氏体钢 等离子体面材料 等离子界面互作用 高参数运作
  • 简介:HT-7数据处理系统向分布式处理升级为例,描述了RTSS仿真为基础的系统性能评价技术.仿真与分析结果都表明客户/服务器工作方式比传统的分时方式性能有很大提高.客户/服务器方式使得在线系统的数据显示时间、实时数据处理时间和数据传输时间都大大缩短,提高了离线系统的负载处理能力,并降低了离线系统的平均系统等待时间.

  • 标签: 数据处理系统 客户/服务器 系统性能评价
  • 简介:据德国马普协会等离子体物理研究所的研究人员称,完全用钨包覆的核聚变防泄漏系统墙壁具有优异的热性能,由氢引起的爆裂低而且没有氚的长期积聚。在百分之一的钨中仅有约万分之几的钨会渗透到等离子体核心中,几乎对核聚变当量没有影响。马普协会等离子体物理研究所对钨进行的试验包括将钨用作防泄漏系统墙壁的特殊区域,

  • 标签: 金属钨 托卡马克装置 核聚变 等离子体物理研究所 屏蔽材料 研究人员
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  • 简介:通过几项技术改造,将HT-L炉装置的废热、富余蒸汽进行回收再利用,转化为电能,送公司内部电网使用,既减少了水的排放量,又降低了消耗,经济效益明显。

  • 标签: HT—L炉 节能减排 技改
  • 简介:随着现代生活对信息安全越来越高的要求,Mifare由于其优良的防护保密性能、防冲突功能,已经替代传统的磁卡、Temic和IC,彻底改变了人们的生活方式。针对近两年市场上屡屡出现IC、M1被黑客破译的现象。

  • 标签: 爱迪尔 MIFARE卡 出炉 新鲜 防冲突功能 信息安全
  • 简介:Hightimeresolutionmeasurementsoftheelectrostaticfluctuations,radialelectricfieldErandturbulence-inducedelectronfluxΓehavebeenperformedacrossthetransitionoflowerhybridcurrentdriveimprovedconfinementwithagraphiteLangmuirprobearrayatthelastclosedfluxsurfaceoftheHT-7tokamak.ThedecreaseofΓeisdominatedbythesuppressionoffluctuationlevels,whichfollowsthechangeofEr.AreversalofthepoloidalpropagationdirectionofturbulencedemonstratesthatthepoloidalpropagationisdominatedbyEr×Bφdrift.Theenhancementofpoloidalcoherenceaccompaniesthefluctuationsuppression,whichsuggeststhesubtlevariationofturbulencefeatures.

  • 标签: 等离子体 TOKAMAK 封闭磁通面