The horizontal phosphor screen's position beneath a sample has two major advantages compared to the vertical standard setup:
- one order of magnitude stronger signal
- lowest possible gnomonic projection distortions
The significantly stronger signal allows to acquire orientation maps with small apertures enabling best spatial resolution. Results on different materials showed that effective spatial resolution is 3 nm or even better. Working at low acceleration voltages down to 5 kV is also possible. This helps to reduce the mean free path and thus to increase the yield of Kikuchi diffraction signal. This is extremely useful when analyzing thin and “lightweight” samples. Distortions caused by gnomonic projection are a common issue in EBSD and especially affect TKD analysis when using the vertical phosphor screen. However, OPTIMUS™ TKD allows to exactly match the phosphor screen's center with the pattern center thus enabling best geometric conditions even compared to EBSD. The resulting Kikuchi patterns have minimum distortions which significantly improves band detection and subsequent indexing accuracy.