简介：SupersonicMolecularBeamInjection(SMBI)isanewfuellingmethodforTokamaksandhasrecentlybeenimprovedtoenhancethefluxofthebeamandtomakeasurveyoftheclustereffectwithinthebeam.Thereareaseriesofnewphenmnena,whichimplicatetheinteractionofthebeam(includingclusters)withthetoroidalplasmaofHiL-1MTokamak.TheHαsignalsfromtheedgeshowaregularvariationaroundthetorus.Aroundtheinjectionport,theedgeHαsignalsarepositiverectangularwave,whichisconsistentwiththatoftheinjectionbeampulses.Theedgeelectrontemperature,measuredwithmovableLangmuirprobes,decreasesbyanorderofmagnitudeandthedensityincreasesbyanorderofmagnitude.Hαemissionatthebeaminjectionport,measuredwithCCDcameraatanangleof13.4degreestotheSMBIline,showsmanyseparatepeakswithinthecontourplot.Thesepeaksmayshowthestrongemissionproducedbytheinteractionofthehydrogenclusterswiththeplasma.Hydrogenclustersmaybeproducedinthebeamaccordingtotheempiricalscaling(Hagena)lawofclusteringonset,heredisthenozzlediameterinμm,P0thestaguationpressureinmbar,T0thesourcetenperatureinK,andkisaconstantrelatedtothegasspecies.IfΓ*>100,clusterswillbeformed.InpresentexperimentΓ*isabout127.

简介：MoleculardynamicssimulationsareperformedtoinvestigateCF3continuouslybom-bardingtheamorphoussiliconsurfacewithenergiesof10eV,50eV,100eVand150eVatnormalincidenceandroomtemperature.TheimprovedTersoff-Brennerpotentialswereused.Thesimu-lationresultsshowthatthesteady-stateetchingratesareabout0.019,0.085and0.1701for50eV,100eVand150eV,respectively.Withincreasingincidentenergy,atransitionfromC-richsurfacetoF-richsurfaceisobserved.IntheregionmodifiedbyCF3,SiFandCFspeciesaredominant.

简介：Synchrontronradiationx-rayreflectivitymeasurementisusedtostudytheconcentrationprofileofaδ-dopedErlayerinSiepitaxialfilmgrownbymolecular-beamepitaxy.Theoscillationofthereflectivityamplitudeasafunctionofreflectionangleisobservedintheexperiment.Bydoingatheoreticalsimulation.theconcentrationprofileofEratomscouldbederied.Itisshownthattheoriginallygrownδ-dopedErlayerchangesintoanexpionentiallydecayedfunctionduetotheErsegregation.Thetemperaturedependenceofthe1/edecaylengthindicatesthatthesegregationisakineticallylimitedprocess.Theactivationenergyisdeterminedtobe0.044±0.005eV.

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简介：WereportonastudyofinterfacialstructureofGaNfilmsgrownonGaAs(001)substratesbyplasma-assistedmolecularbeamepitaxyusingx-raygrazing-anglespecularreflection.WeshowthatinterfaciallayerswithelectrondensitiesdifferingfromthoseofGaNandGaAswereformedupondepositionofGaN.Itisalsofoundthattheinterfacialstructureofoursystemsdependsstronglyonthecourseoftheinitiallayerdeposition.ThephasepurityoftheGaNfilmswasexaminedbyx-rayreciprocalspacemapping.Asimplekineticgrowthmodelsuggestedbyourresultshasbeenpresented.