简介:Alargediamondcrystalupto500μmindiameterwithasmooth(100)facetatitstophasbeensynthesizedonMosubstratethroughmicrowaveplasmachemicalvapordeposition(MPCVD).Itsmorphologyandqualitywerecharacterizedbyscanningelectronmicroscopy(SEM),andthegrowthmechanismwasroughlyillustratedfrombothmacroscopicandmicroscopicviewpoints.Itwasfoundthatmorphologicalinstabilitiesareamajorfactorresultinginsynthesisoflargediamondcrystals,moreover,highmicrowavepowerdensity(MPD),highCH4concentrations,highpressure,highsubstratesurfacetemperatureandtheadditionofasmallamountofO2werealsonecessaryforthesynthesisoflargediamondcrystals.
简介:Neutralbeaminjection(NBI)isrecognizedasoneofthemosteffectivemeansforplasmaheating.A100slongpulseneutralbeamwith30keVbeamenergy,10Abeamcurrentanda100slongpulsemodulatingneutralbeamwith50keVbeamenergy,16AbeamcurrentwereachievedintheEASTneutralbeaminjectoronthetest-stand.ThepreliminaryresultssuggestthatEAST-NBIsysteminitiallypossesstheabilityoflongpulsebeamextraction.