Bruker have introduced the new OPTIMUS™ TKD detector head for Transmission Kikuchi Diffraction (TKD) in the scanning electron microscope (SEM). This innovative new product features a horizontal phosphor screen that can be placed directly beneath electron-transparent samples. OPTIMUS™ can be used interchangeably with the standard detector head of all Bruker e-Flash EBSD detectors, giving easy access to both EBSD and TKD using the same detector.
The OPTIMUS™ TKD detector head provides optimum geometric conditions, resulting in two major advantages compared to TKD using standard EBSD detectors that use only a vertical screen. Firstly, the signal is acquired where it is strongest and secondly the produced patterns display the lowest possible distortion.
Thanks to the gain in signal provided by OPTIMUS™, users can either acquire data faster using the same SEM probe current as before or obtain improved lateral spatial resolution by using lower probe currents.
Alternatively, the SEM acceleration voltage can be reduced which improves the analysis of very thin samples, as low energy electrons are more likely to be diffracted on the grain lattices. The second advantage, minimal pattern distortion, leads to further improvement of both band detection and indexing accuracy.
OPTIMUS™ can also be used to acquire Selected Area Electron Diffraction (SAED) patterns very similar to those seen in a traditional transmission electron microscope, but at a fraction of the cost and effort.
The ARGUS™ direct electron detection system integrated into OPTIMUS™ benefits from the same ideal geometric conditions. Dark field and bright field images acquired with ARGUS™ in transmission mode show nanometer scale microstructural features as well as details like single dislocations or dislocation walls in deformed materials.
The OTPIMUS™ TKD detector head is designed to be compatible with all Bruker e-Flash EBSD detectors. Existing detectors can be easily upgraded by trained users in less than 20 minutes. Depending on the measurement task at hand, users can switch between TKD and EBSD analysis. The new OPTIMUS™ TKD detector head works perfectly in combination with the Bruker TKD sample holder as well as with Bruker’s XFlash® EDS detectors.