A CONFIGURABLE ANGLE-RESOLVING DETECTOR SYSTEM IN STEM

A configurable angle-resolving detector system for a STEM has been dev eloped, which opens a universal and flexible way of masking the diffra ction pattern. The diffraction pattern can be divided in up to 16 area s of arbitrary shapes which may be defined analytically, or be constru cted interactively under observation of the diffraction pattern. The s ignals from such areas are separately accumulated and processed. A sim ple demonstration is shown for two MgO crystals with different orienta tion. The special case of differential phase contrast is demonstrated for a hole in an amorphous carbon film.