Principle Components of an Electron Backscatter Diffraction (EBSD) System
Typically an EBSD system consists of:
A scanning electron microscope (SEM)
A crystalline sample tilted to 70º from horizontal, by use of the SEM stage or a pretilted holder.
A phosphor screen, which is fluoresced by the electrons scattered from the sample.
A CCD or CMOS sensor (with a lens system or fibre-optics) for viewing the pattern formed on the phosphor screen.
An insertion mechanism, which accurately controls the position of the detector when it is in use and retracts the detector to a safe position when it’s not in use, so as to prevent interference with SEM operation.
Additionally, the EBSD detector might have elevation controls, which allows the acquisition geometry to optimised for a larger range of working distances.
Electronics to control the SEM, including the beam and stage movements.
A computer and software to control the EBSD experiments, to collect and analyse the diffraction patterns, and display the results.
Software control of the detector insertion and elevation, to maintain calibrations and make the system easy to use.
Forescatter diodes (FSD) mounted around the phosphor screen, used to generate microstructure images of the sample before collecting EBSD data.
The EBSD system can optionally be integrated with an EDS system
Animation showing an EBSD detector mounted on the SEM chamber, together with an EDS detector. Some EBSD detectors have elevation control, as shown, allowing greater versatility in the sample to detector geometry
EBSD software controls the whole acquisition process, from electron beam control to pattern indexing, and enables detailed interrogation of the EBSD data