简介:基于4阶Runge-Kutta法,介绍了“强光一号”加速器长脉冲状态的电路模型。该模型不仅考虑了电爆炸丝导体断路开关(electronexplosiveopeningswitch,EEOS)金属丝的电阻率随比作用量变化的特性,而且考虑了油间隙和真空二极管间隙击穿过程中等效阻抗的变化特性。仿真结果表明,该模型能够更好地反映EEOS的初始参数对放电回路电流和电压的影响规律,能够为加速器的运行和性能提升提供有力的技术参考。通过仿真计算和理论分析,认为“强光一号”加速器的初级储能系统——直线型变压器(lineartransformerdriver,LTD)经过升级改造后,EEOS的工作电压能够提升大约20%,且获得了EEOS最佳工作状态的参数。
简介:HL-2AisanewdivertortokamakunderconstructionatSouthwesternInstituteofPhysics(SWIP),Chengdu,China,basedontheexperiencefromHL-1andHL-1M.HListheshorttermofaChinesewordthatmeans"ToroidalCurrentDevice".ThemainobjectivesofHL-2Aaretoproducemoreadaptabledivertorconfigurationstostudyenergyexhaustandimpuritycontrol(thefirstdivertortokamakplasmainChina),andtostudyenhancedplasmaconfinementbyprofilecontrolandmoderateplasmashaping.
简介:Atokamakplasmadischargeinvolvesaseriesofcomplexandconcertedactionsconductedbyitscontrolsystem.TheHL-2Acontrolsystemcanbedividedintotwopartst,themachinecontrolsystemandthedischargecontrolsystem.Themachinecontrolsystem,whichconsistsofindustrialPC(IPC),configuresandoperatesthetokamak'svarioustechnicalsubsystems.Timingsys-temisintegratedintomachinecontrolsystemgivingabsolutetimeforallsubsystems.Thedischargecontrolsystem,
简介:Run2atFermilabbeganinMarch,2001,CDFwillcollectdataatamaximumrateof20MByte/secduringtherun.Theofflinereconstructionofthisdatamustkeepupwiththedatatakingrate.ThisreconstructionoccursonalargePCfarm,whichmusthavethecapacityforquasi-realtimedatareconstruction,forreprocessingofsomedataandforgenerationandprocessingofMonteCarlosamples.Inthispaerwewillgivethedesignrequirementsofrthefarm,describethehardwareandsoftwaredesignusedtomeetthoserequirements,describetheearlyexperienceswithRun2dataprocessing,anddiscussfutureprospectsforthefarm,includingsomeideasaboutRun2bprocessing.
简介:ThreeseriesofCeO2/CuOsampleswerepreparedbyimpregnationmethodandcharacterizedbyXRD,N2adsorption-desorption,temperatureprogrammedreduction(TPR),XPSandTEMtechniques.IncomparisonwiththesamplespreparedwithCuOasinitialsupport,thesampleswithCu(OH)2asinitialsupporthavehigherreducibilitiesandsmallerrelativeTPRpeakareas,andalsolargerspecificsurfaceareasatcalcinationtemperaturesof400℃–600℃.Asaresult,Cu(OH)2isbetterthanCuOasinitialsupportforpreferentialoxidationofCOinexcessH2(CO-PROX).Thebestcatalyticperformancewasachievedonthesamplecalcinedat600℃andwithanatomicratioofCe/Cuat40%.XPSanalysesindicatethatmoreinterfacelinkagesCe-O-Cucouldbeformedwhenitwascalcinedat600℃.AndtheatomicratioofCe/Cuat40%ledtoaproperreducibilityforthesampleasillustratedbytheTPRmeasurements.
简介:WehavestudiedtheangularmagnetoresistanceofironpnictidesBaFe2-xNixAs2,whichshowsclear180degreeperiodicityasfittedbyacosinefunction.Inthex=0.065sample,thephaseofthetwo-foldsymmetrychanges90degreesabovethetetragonal-to-orthorhombicstructuraltransitiontemperatureTs.Sincethephaseatlowtemperatureisassociatedwiththerotationoforthorhombicdomainsbymagneticfield,weshowthatevenvacuumgreasecanpushthepresenceoforthorhombicdomainsattemperaturesmuchhigherthanTs.Ourresultssuggestthatresidualstressmayhavesignificanteffectsinstudyingthenematicordersanditsfluctuationsinironpnictides.
简介:Wereporteddiversesolitonoperationsinathulium/holmium-dopedfiberlaserbytakingadvantageofataperedfiber-basedtopologicalinsulator(TI)Bi2Te3saturableabsorber(SA).TheSAhadanonsaturablelossof53.5%andamodulationdepthof9.8%.Stablefundamentallymode-lockedsolitonsat1909.5nmwithdistinctKellysidebandsontheoutputspectrum,apulserepetitionrateof21.5MHz,andameasuredpulsewidthof1.26pswereobservedinthework.Byincreasingthepumppower,bothbunchedsolitonswithsolitonnumberupto15andharmonicallymode-lockedsolitonswithharmonicorderupto10wereobtained.Toourknowledge,thisisthefirstreportofbothbunchedsolitonsandharmonicallymode-lockedsolitonsinafiberlaserat2μmregionincorporatedwithTIs.