The X-ray micro-Tomography Facility at the Advanced Light Source has been in operation since 2004. The source is a superconducting bend magnet of critical energy 11.5 keV; photon energy coverage is 8-45 KeV in monochromatic mode, and a filtered white light option yields useful photons up to 50 keV. A user-friendly graphical user interface allows users to collect tomographic and radiographic data sets with options including tiled and time series data sets. We will focus on recent projects that utilize sample environments for in-situ imaging. These environments include a high pressure triaxial flow cell which has allowed study of supercritical CO2 transport through brine-saturated sandstone at pressures typical of in-situ conditions for subsurface CO2 sequestration and water transportation within live plants.
We employ a coded aperture pattern in front of a charge couple device (CCD) pixilated detector to image fluorescent xrays (6-25KeV) from samples irradiated with synchrotron radiation. Coded apertures encode the angular direction of xrays, and given a known source plane, allow for a large Numerical Aperture x-ray imaging system. The algorithm to develop the free standing coded aperture pattern of the Non-Two-Holes-Touching (NTHT) was developed. The algorithms to reconstruct the x-ray image from the encoded pattern recorded are developed by means of modeling and confirmed by experiments on standard samples. Spatial resolution and efficiency are determined for the next development stage whereby an energy resolving pixilated CCD will be deployed allowing for elemental imaging.