简介:TheHTScurrentleadsofsuperconductingmagnetsforlargescalefusiondevicesandhighenergyparticlecolliderscanreducethepowerconsumptionforcoolingby2/3comparedwithconventionalleads.Theresistivesectionsofhigh-ratedcurrentleadsareusuallymadeofaheatexchangercooledbygasflow.Thesupplyofthecoolingmassflowincursmorethan90%ofthecoolingcostfortheHTSleads.Themassflowraterequirementdependsnotonlyonthelengthandmaterialoftheresistiveheatexchanger,butalsoontheheattransfercoefficientandHEXsurface,thejointresistanceatthecoldendanditscoolingapproach.Thedesignandoperationofasheet-stackHEXwithalargerspecificsurfaceandamuchsmallerhydraulicdiameterarepresentedinthepaper.ThetestresultsofanHTSleadoptimizedfor8kAshowthata98.4%efficiencycanbeachieved.
简介:StableoperatingregionintheHL-1Mtokamakhasbeenextendedbymeansofwallconditioning,corefuellingandcurrentcontroltechniques.Themechanismsoftheextensionareanalyzedinthispaper.Lithiumizationdiminishestheimpuritiesandhydrogenrecyclingtothelowestlevel.Afterlithiumizationahighdensityupto7×1019m-3wasobtainedeasilybystronggaspuffingwithordinaryohmicdischargealone.MoreattractivelywefoundthatmetalLi-coatingexhibitedtheeffectsofwallstabilization.Thelowqalimitwithhigherdensitywasextendedbyafactorof1.5~2incomparisonwiththatforboronization,and1.2forsiliconization.Siliconizationnotonlyextendedstableoperatingregionsignificantlybyitself,butalsoprovidedagoodtargetplasmaforotherexperimentsofraisingdensitylimit.Corefuellingschemesarefavourableespeciallyforsiliconizedwallwithahigherlevelofmedium-Zimpurity(Z=14).Aftersiliconizationthemaximumdensitynearto1020m-3wasachievedbyacombinationofsupersonicmoleculebeaminjectionandmultipelletinjection.ThenewdefinedslopeofHugilllimitillustratingmoreclearlythesituationunderlowqaandhighnedischargeswascreatedtoindicatethenewregionextendedbycombiningIpramp-upwithcorefuelling.TheslopewithalargeMurakamicoefficientincreasedbyafactorof50~60%.
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简介:Vacuumtreatmentandion-beambombardmentaretwomajorprocessesinthelowenergyion-beamimplantation.Toaccuratelystudythecontributionsofthesetwomajorfactorstothebioeffectsseparately,theM_1generationvariationofArabidopsisthalianawithion-beamimplantationandvacuumtreatmentwerecomparedthroughaseriesofkeyplantdevelopmentparametersincludingmorphologicalobservation,biochemicalassayandRAPD(randomamplifiedpolymorphicDNA)analysis.Theresultsshowedthation-beamimplantationhadobviouseffectonalmostalloftheseparameters,andthevacuumtreatmenthadsomeimpactsonseveralmorphologicalparameterssuchastheboltingtimeandthelengthoftheprimarystem.Takingtheresultstogether,theindicationisthatvacuumtreatmenthassomeslightcontributionstothebioeffectsofion-beamimplantationwhileion-beambombardmentitselfisthemajorcreatorofthebioeffects.
简介:Neutralbeaminjection(NBI)isrecognizedasoneofthemosteffectivemeansforplasmaheating.A100slongpulseneutralbeamwith30keVbeamenergy,10Abeamcurrentanda100slongpulsemodulatingneutralbeamwith50keVbeamenergy,16AbeamcurrentwereachievedintheEASTneutralbeaminjectoronthetest-stand.ThepreliminaryresultssuggestthatEAST-NBIsysteminitiallypossesstheabilityoflongpulsebeamextraction.
简介:IntheframeworkoftheITER,qualificationtests,thefirstChinaTFconductorsample(CNTFl)wastestedattheSULTANfacility.ThesamplewasmadeoftwoTFconductorsectionsmanufacturedfromidenticalinternalstannumstrandsprovidedbytheOxfordSuperconductingtechnologycompany(OST).Inordertoevaluatetheconductorperformance,thecurrentsharingtemperature(Tcs)wasmeasuredatspecifiedelectromagneticloadcyclingsteps.BothconductorsectionsoftheCNTFlsampleshowedidenticalperformance.Tcswas7.2Kbeforecyclingloading,and6.9Kevenafter950cycles,withoutsignificantdegradation,whichsubstantiallyexceedstheITERrequirementof5.7K.ThetestsoftheCNTFlconductorsampleshowedthattheelectromagneticcyclicloadexhibitedanegligibleeffectontheconductorperformance.Thecouplingtimeconstant8forAClosswas214msand71.52msbeforeandafterthecyclingload,respectively.Thetestresultsofthesamplearecomparedwiththestrandperformanceandparametermodelanalysis.
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简介:软X射线计量标准的建立和软X射线探测器标定是目前国内急需解决的课题,本文简单介绍了两套北京同步辐射软X射线装置,它们主要用于软X射线光学元件测量和软X射线探测元、器件的标定。另外给出了近年来在软X射线测量装置上开展的计量标准和探测器标定方面的研究结果。