Frequently asked questions
Who is allowed to scan at the facility?
Everybody from the scientific community and industrial world are welcome at our facility for joint research. Industrial services are provided by our spin-off XRE.
Can I just make a test?
Unfortunately, the operation of a high-resolution scanner has its maintenance costs. For academic people and innovative research, our institute will only charge part of this cost. Feel free to contact us at ugct@ugent.be with your inquiry.
What is the maximum or minimum size and weight of the sample?
For the high-resolution scanners there is a maximum weight of 5 kg. The maximum size can be 200 mm. Larger samples can be scanned in the medical scanner or if the samples are really dense they could be scanned at the electron LINAC. Nano-CT is used for samples with a diameter less than 2 mm.
Do I need to prepare my samples?
Sample preparation is not necessary. However, samples have to be stable and positioned on the rotation motor. Please contact us at ugct@ugent.be for more information.
What resolution can be expected for my sample?
The easiest way to estimate the spatial resolution of the scan is dividing the maximum width of the sample by the number of pixels in one detector row. A typical number of pixels in one row is 1000, which makes it possible to achieve a resolution of approximately 1/1000th of the sample size. A cylinder with a diameter of 2cm can be scanned at a resolution of 20 microns. To achieve a resolution of 2 microns, you need a sample of only 2mm in diameter.
How long does one CT scan take?
The scan time is proportional to the signal to noise. The longer we measure, the better the quality. A fast scan takes 10 min. A high-quality scan can take up to 4 hours.
How much does it cost to scan a sample?
The cost depends on the scientific output and the required assistance. Please contact us at ugct@ugent.be for more information.
What do the gray values of the slices mean?
The X-ray beams are polychromatic, which means that the X-rays have a different wavelength or energy. The attenuation µ of these X-rays inside the object is energy dependent and therefore the parameter µ(E) is not a constant. The gray values are a combination of the local object density and the local average attenuation coefficient. By using X-ray filters it is possible to reduce the contribution of the parameter µ and finally get a good idea of the density of the object. For most samples the density will provide an idea of the internal structure.
Do you also provide quantitative information?
Post processing to obtain quantitative information is possible.
- Bone densitometry
- Wall thickness inspection
- Electronics analysis
- Pore-size analysis
How do I transfer the data?
We provide FTP or HTTP access to the original data and the reconstructed slices through the object. Users can bring their external hard disk to our facility to transfer their data. Links to the FTP and HTTP server will be provided by us.
What about confidentiality?
All scans are stored in the CT library where all data is password-protected. Joint research projects can be fully confidential if this is required. Industrial services by the spin-off have full confidentiality.