GIF

Stands for Gatan Imaging Filter:

Is installed below a TEM, allows to record electron energy loss spectra (EELS) and element specific images (elemental maps) by means of the electron spectroscopic imaging (ESI) technique. Mostly, the so-called three-window method is applied for mappings (see figure): an image is taken after a suitable ionisation edge of the corresponding element (post-edge image, ΔE3), two additional images (pre-edge 1, ΔE1, and pre-edge 2, ΔE2) are recorded at energy losses smaller than the ionisation edge. Only the electrons passing through the selected energy slit contribute to these images. Specimen drift during recording of these images is compensated for by a cross-correlation algorithm implemented in the software of the GIF. The pre-edge images are used for an approximate determination of the unspecific background which is then subtracted from the post-edge image leading to an elemental map with enhanced contrast. Alternatively, the post-edge image can be divided by a pre-edge image (ratio method).

GIF 860	1kx1k	retractable TV rate camera
GIF 850	2kx2k	retractable TV rate camera
GIF 863 Tridium	2kx2k	Ultrascan 1000
GIF 865 Tridium ER	2kx2k	Ultrascan 1000

On Titan off axis TV camera are not supported. A presence of the TV camera discriminates between the 850/860 and newer Tridium series.

All GIF's are mounted with a camera block. This is easier for alignments when you add a so called pre-GIF or high-res camera. Main precondition is that a high-res camera needs to be retractable. Only Gatan cameras have this ability: [[US 1000]], US 2000, [MSI 794]]