A channel plate detector for electron backscatter diffraction

Electron backscatter diffraction (EBSD) using a scanning electron microscope has proven to be a valuable means for determining the crystal orientation of crystallites as small as ∼0.25 μm. However, it is still not widely used. One deterrent is the high cost of the image intensified video camera system that is commonly used to record the weak EBSD images produced on a phosphor screen. A much less expensive detector system has been devised using a microchannel plate (MCP) electron multiplier to provide the necessary gain in image intensity and a standard video camera to record the image. Excitation of the MCP by secondary electrons and low energy backscattered electron is prevented by a thin aluminum foil on the MCP front surface. The benefits and disadvantages of this approach to EBSD are presented, together with typical EBSD images obtained from it.