ARGUS FSE/BSE Imaging System

The eFlash EBSD detectors are optionally available with the ARGUS™ forescattered electron (FSE) and backscattered electron (BSE) imaging system. This further increases the versatility of the detectors and provides valuable additional information for meaningful and efficient microstructure characterization.

The set of two BSE detectors is mounted above the screen of the EBSD detector. The three FSE detectors are below the screen. This position of the detectors does not affect the performance or user-friendliness of the eFlash, the screen remains user replaceable. All electronics required for the operation of the FSE/BSE detectors are already included in the eFlash+ detector encasement. Apart from the convenience this also ensures that signal loss is minimized as the preamplifiers are close to the detectors.

BSE detectors for improved image quality

Due to the high sample tilt in EBSD mode, standard SEM SE and BSE detection systems tend to produce noisy images of low quality. The ARGUS™ BSE detectors are positioned optimally to acquire the BSE signal from samples with a high tilt angle. This includes the location above the screen and the inclination towards the sample, both of which ensure optimum signal strength. Also, the EDS detector can fit between the BSE detectors, to provide best possible conditions for simultaneous EDS and EBSD acquisition. The signal produced can be used individually or mixed with that from the FSE detectors.

Colorful orientation contrast images with the ARGUS™ FSE detectors

Each of the three ARGUS™ FSE detectors positioned below the phosphor screen captures a different part of the highly anisotropic diffracted forescattered signal (Kikuchi pattern). This allows the ARGUS™ system to detect the slightest signal variation, due to orientation change when scanning over a polycrystalline sample. Using color coding (RGB) to display the signal, even very small orientation changes are made visible for the human eye. This feature is unique to the ARGUS™ system. (For more details on the technique please refer to A. P. Day et al., Journal of Microscopy, Vol. 195, Pt. 3, September 1999, pp. 186–196.)

Signal optimization is fast and fully automatic thanks to its complete integration into the ESPRIT software. Also the FSE signal can be combined with the BSE signal.

ARGUS™ images have both scientific and practical applications.