Multi-scale analysis of samples with an emphasis on geological examples

In this issue we highlight multi-scale analysis of samples with an emphasis on geological examples. This will logically lead us to a discussion on selection of sample size and influences on the attainable image quality. We are proud to introduce the latest addition to our portfolio: the SkyScan 1275 – fast automated, desk-top X-ray microtomograph.
Finally we are glad to announce that the international Bruker microCT User Meeting 2016 will be held in Brussels from 9th to 12th of May. We hope to welcome you all! More details to follow.

Multi-scale analysis

For X-ray tomography the image quality that can be achieved is strongly correlated to the size of a sample. In some cases the required image quality and sample volume are not compatible. Combining scan data acquired at different resolutions for different sample sizes can bring a solution to this.
What image pixel can be achieved was covered in the newsletter of February. This already gives a first indication of resolution can be achieved. Additionally the attenuation of the sample needs to be taken into account. In principle if the sample composition (physical and chemical) and the system characteristics (X-ray beam energy profile, detector sensitivity etc.) are known, the resultant image resolution can be simulated. In practice however, in the majority of cases, this is determined empirically or estimated on the basis of operator experience.

Frequently in core analysis CT scans from two and more length scales are combined. In the figures a sample of Savonniere limestone is shown, scanned at three resolutions. The (a) is a plug ~38mm in diameter, (b) a plug ~9.5mm in diameter and (c) a cuboid with a ~2.5mm side. The respective image pixel sizes are 22.0μm, 5.5μm and 2.0μm. As a manner of illustration a graph of the cumulative volume of the pore thickness is depicted in (d) shown in the next page.
The information extracted from the various length scales can then be combined to quantify and model the sample behavior overall.

pictures "a - b - c"
picture "d"

Introduction of SkyScan 1275 – Fast Automated, Desk-Top X-Ray Microtomograph

The new SkyScan1275 desk-top microtomograph is specially designed for fast scanning using new advances in the technology of X-ray sources and efficient flat-panel detectors. It opens the possibility for reducing scan time down to a few minutes without compromising image quality. The SkyScan1275 provides a high level of automation. Simple push of a button on the front of the system starts an auto-sequence of a fast scan followed by reconstruction and volume rendering executed during scanning of the next sample. For more information we kindly refer to the website, where the product brochure can also be downloaded.