文档介绍
“Theinstrument”Lecture4ReviewofimagingmodesSystemoverviewReviewofimagingmodes–Condensersystem–Objectivelens&samplestage–Formingimagesanddiffractionpatterns•TEMmode•STEMmodeMicroscopealignment–Philosophy–Step-by-stepCalibrations–Magnification,cameralength,rotation(ifneeded),convergenceangleTEMoverviewTEMcrosssectionElectronGunCondenserSystemObjectiveSystemProjectorSystemTEMcrosssection(simplified-somewhat)ElectronGunCondenserSystemObjectiveSystemProjectorSystemTEMcrosssectionSourceElectronWehneltcupgunGundeflectorsCondenserC1“SpotSize”systemC2“Brightness”C3“Convergence”CApertureCStigmatorsBeamdeflectors/scancoilsObjectiveObjectivelenssystemSampleObjapertureObjstigmatorSelectedAreaapt.Intermediate1IntermediateIntermediate2systemIntermediate3ProjectorCondensersystemGoal:placethebeamonthes