Basics of Computed Tomography (CT)

CT produces a volume reconstruction of a sample using X-rays.

The UChicago PaleoCT machine

The CT scanner at the UChicago PaleoCT lab is a GE v|tome|x s with dual tubes: a microfocus directional 240kV tube, and a nanofocus transmission 180kV tube.

There are three basic parts to our CT scanner: the tubes (source of the X-rays), the CNC (which holds the sample), and the detector.

As mentioned above, our scanner has two tubes. One is a microfocus tube which can generate up to 240kV and is good to use for dense or large samples. The other is a nanofocus tube which can generate up to 180kV and can achieve a resolution as low as 0.2 µm, which makes it ideal for very small samples.

The CNC is the apparatus that holds the sample and moves in the X, Y, and Z directions. It has a 3 jawed self-centering machine chuck, which the sample is mounted to during scanning.

The detector panel