OPTIMUS™ TKD Detector Head

Bruker’s high performance e-Flash EBSD detector series can now be configured with the OPTIMUS™ TKD detector head which was specifically designed for best sample-detector geometry for on-axis Transmission Kikuchi Diffraction analysis (TKD) in SEM. The detector head not only acquires Kikuchi patterns with unmatched sensitivity, but even provides access to SAED (Selected Area Electron Diffraction) like patterns.

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 thus enabling improved spatial resolution. Results on various materials indicate an effective spatial resolution of 2 nm or better when using a high-end FE-SEM. 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 ideal geometric conditions, better even than what standard EBSD geometry offers. The resulting Kikuchi patterns have minimum distortions which significantly improves band detection and subsequent indexing accuracy.

OPTIMUS™ TKD is equipped with the ARGUS™ imaging system that enables brilliant Dark and Bright Field like imaging with details down to nanometer scale, practically transforming your SEM into a "low-kV TEM". ARGUS™ can be used to display individual dislocations and networks of dislocation walls in deformed materials. The Dark Field like images show 3D information on boundary plane position and inclination.

Every existing e^-Flash detector can be fitted with the OPTIMUS™ TKD detector head. The exchange can be easily done in less than 10-15 minutes by a trained user. This allows an easy and fast switch between EBSD and TKD mode whenever needed. OPTIMUS™ TKD features Bruker's advanced collision protection system: in the unlikely event of collision the detector immediately retracts at a speed of 10 mm/s which significantly reduces the risks of any damage. The OPTIMUS™ TKD detector head seamlessly works with Bruker’s TKD Professional Toolkit for SEM including TKD sample holder, the XFlash® EDS detector series for simultaneous TKD/EDS measurements and the ESPRIT 2 analytical software suite.