Reading the tomography graphs » History » Version 1
Anchi Cheng, 07/15/2010 08:47 PM
| 1 | 1 | Anchi Cheng | h1. Reading the tomography graphs |
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| 3 | To first approximation, if the object tomography application try to track is perfect in xy but off in z ( off eucentric), the movement of the z-projected object during tilting follows a sine curve. On the other hand, if the object is perfect in z but offset on the xy plane in direction perpendicular to the tilt axis, the movement of the projected object follows a cosine curve, as show here: |
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| 4 | !tilt.png! |
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| 6 | Therefore, the curve below on x-axis which is almost perpendicular to the tilt axis suggests the specimen is 10 um off in z and the tilt axis passes quite close to the center of the CCD. |
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| 7 | !zoff.png! |