学科分类
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19 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:Togetanoptimizedpulsedelectricalplasmadischargereactorandtoincreasetheenergyutilizationefficiencyintheremovalofpollutants,twohybridplasmadischargereactorsweredesignedandoptimized.Thereactorswerecomparedviathedischargecharacteristics,energytransferefficiency,theyieldsoftheactivespeciesandtheenergyutilizationindyewastewaterdegradation.TheresultsshowedthatunderthesameACinputpower,thecharacteristicsofthedischargewaveformofthepoint-to-platereactorwerebetter.UnderthesameACinputpower,thetworeactorsbothhadalmostthesamepeakvoltageof22kV.Thepeakcurrentofthepoint-to-platereactorwas146A,whilethatofthewire-to-cylinderreactorwasonly48.8A.Thepeakpowersofthepoint-to-platereactorandthewire-to-cylinderreactorwere1.38MWand1.01MW,respectively.Theenergyperpulseofthepoint-to-platereactorwas0.2221J,whichwasabout29.4%higherthanthatofthewire-to-cylinderreactor(0.1716J).Toremove50%AcidOrange7(A07),theenergyutilizationsofthepoint-to-platereactorandthewireto-cylinderreactorwere1.02×10-9mol/Land0.61×10-9mol/L,respectively.Inthepoint-toplatereactor,theconcentrationofhydrogenperoxideinpurewaterwas3.6mmol/Lafter40minofdischarge,whichwashigherthanthatofthewire-to-cylinderreactor(2.5mmol/L).Theconcentrationofliquidphaseozoneinthepoint-to-platereactor(5.7×10-2mmol/L)wasabout26.7%higherthanthatinthewire-to-cylinderreactor(4.5×10-2mmol/L).Theanalysisresultsofthevarianceshowedthatthetypeofreactorandreactiontimehadsignificantimpactsontheyieldsofthehydrogenperoxideandozone.ThemaindegradationintermediatesofA07identifiedbygaschromatographyandmassspectrometry(GCMS)wereaceticacid,maleicanhydride,pbenzoquinone,phenol,benzoicacid,phthalicanhydride,coumarinand2-naphthol.Proposeddegradationpathwayswereelucidatedinlightoftheanalyzeddegradationproducts.

  • 标签: 放电反应器 等离子体放电 废水降解 酸性橙7 染料 双杂交
  • 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:Inthiswork,aplasma-solutionsystemwasappliedtothedegradationofAcidOrange7(A07).Theeffectsofinitialconcentrationandtypeoffeedgases(air,oxygen,nitrogenorargon)werestudied.Astheinitialconcentrationincreasedfrom100mg/Lto160mg/L,thediscolourationrateofA07decreasedfrom99.3%to95.9%,whereastheCODremovalratedecreasedfrom37.9%to22.6%.AirprovidedthebestdiscolourationandCODremovalrates(99.3%and37.9%,respectively).Inthepresenceofazero-valentiron(ZVI)catalyst,theA07CODremovalrateincreasedto76.4%.ThedegradationproductswereanalysedbyaGC-MS,revealingthatthedegradationofthedyemoleculewasinitiatedthroughthecleavageofthe-N=N-bondbeforefinallybeingconvertedtoorganicacids.

  • 标签: 常压等离子体 酸性橙7 溶液系统 COD去除率 GC-MS分析 放电
  • 简介:利用金刚石压砧高压装置(DAC),对Ca3Mn2O7的粉末样品进行了高压能散X射线衍射实验。结果表明,由于岩盐层易被压缩,在压力作用下层状钙钛矿结构锰氧化物Ca3Mn2O7的结构不稳定。在0-35GPa压力范围内,Ca3Mo2O7晶体结构发生了两次相变。在1.3GPa左右,由原来的四方相变为正交相,在9.5GPa左右,又由正交相向新的四方相转变。

  • 标签: 层状钙钛矿 结构 锰氧化物 Ca3Mn2O7 相变 同步辐射
  • 简介:本文通过高分辨X射线衍射及掠入射(GID)的实验方法对生长在SrTiO3衬底上的LLa2/3Ca1/3MnO3和YBaCu3O7单层膜及YBa2Cu3O7-x/La2/3Ca1/3MnO3异质结构双层薄膜的微结构进行了研究。结果发现,所有薄膜都呈c向生长。由于热膨胀系数的不同而引起的热应力使得LCMO膜的晶格参数与靶材的相差较大。La2/3Ca1/3MnO3在单层腹及双层膜中都由靶材的立方结构变成了薄膜状态的四方结构。YBa2Cu3O7在单层膜及双层膜中都由靶材的正交结构变成了薄膜状态的四方结构。La2/3Ca1/3MnO3膜与YBa2Cu3O7膜在不同的样品中处于不同的应力状态。

  • 标签: YBa2Cu3O7-x/La2/3Ca1/3MnO3 异质结构薄膜 微结构 X射线衍射 X射线掠入射 锰酸盐