Upcoming challenges in high-resolution CT below 1 m

Besides the pixel size of the detector and the size of the focal spot the resolution of a computed tomography (CT) setup depends especially on the spatial stability of all components. In this publication we present the performance of our sub--CT components and the limitations resulting from spatial instability of the system. We will show that it is possible to overcome these limitations and reach resolution in the range of 500 nm. The experimental setup is based on high-resolution imaging detectors, a multifocus X-ray tube and a high-precision manipulation system. Our research contains measurements of the effective focal spot size using a resolution test mask and of the long-term stability of the focal spot position due to thermal expansion of the focusing unit. Also the stability of the X-ray intensity that affects the quality of CT will be corrected by additional bright image correction during the measurement. Due to the measured instabilities correction of the origin al images is necessary to achieve highest resolution. Solutions and results will be presented.