Patent ID: 8362428
Filing Date: 2013-01-29
Classification: H01J

Abstract:
1. A transmission electron microscope having: a target body position on the electron optical axis of the microscope, an electrically conductive body off the axis of the microscope, an electron source for producing an axial electron beam which, in use, impinges upon a target body located at the target body position, and a system for simultaneously producing a separate off-axis electron beam which, in use, impinges on the electrically conductive body causing secondary electrons to be emitted therefrom; wherein the electrically conductive body is located such that the emitted secondary electrons impinge on the target body to neutralise positive charge which may build up on the target body, and wherein the system for producing an off-axis electron beam comprises an aperture body positioned between the electron source and the target body position, the aperture body having an axial aperture for transmission of the axial electron beam and further having an off-axis aperture for production of the off-axis electron beam.