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Schlagwörter:
STIM; Tomography
Zusammenfassung:
The feasibility of tomographic reconstruction of biological specimens using scanning transmission ion microscopy (STIM) has already been demonstrated in the past. However, in previous experiments at Leipzig the resolution was limited by an insufficient accuracy of goniometer motion, which resulted in a blurred alignment of the projections. The new stage and goniometer at the LIPSION accelerator laboratory allow a more precise rotation of the sample. Furthermore, a new software was developed, which includes efficient algorithms to correct misalignment errors. STIM tomography experiments using a proton and a molecular beam respectively were carried out on a rust mite (Aculus schlechtendali), on average 25 μm thick, and on unicellular organisms (Thaumatomonas coloniensis) with a diameter below 5 μm. The backprojection of filtered projections (bfp) algorithm was employed for the three-dimensional reconstruction. The reconstruction revealed many structural details including spherical grains of higher density inside the mite’s body of yet unknown origin.
