A mobile in-house built modular X-ray system used primarily as a gantry cone-beam tomograph for biology (small animals, plant roots, seeds etc.) and process tomography applications (manufacturing, environmental research). It features two modules, a gantry frame for performing gantry tomography and a frame that can accommodate the equipment for performing regular cone-beam micro-tomography (3D-CT) and X ray microbeam-fluorescence (µXRF). This multifunctional X-ray system can be used for noninvasive 3-D morphology and composition mapping.
The X-ray sources are of sealed microfocus type with maximum high voltage of 60 kV, maximum power of 50 W and different anode materials (W, Mo or Ag). X ray detection is achieved using a compact high resolution flat pannel (1944 x 1536 pixels, 75 μm pixel size) for tomography and a miniaturized X-ray spectrometer for XRF experiments. A micrometric rotation stage is used for spinning the gantry frame and four micrometric motorized stages aid in sample positioning when using the 3D-CT & µXRF module.
Customized software was developed using LabView for axis manipulation, data acquisition and control. 3-D tomographic reconstructions are obtained by a proprietary highly optimized computer code based on a modified Feldkamp algorithm.
Gantry tomography is used for samples than cannot be moved and need to lie on a sample bed rather than stand in a sample holder. It is the case of small animals, germinating seeds or samples that undergo different processes that can be analised insitu. For the inspection of miniaturised samples the microtomography analysis is guaranteed for feature recognition down to a few tens of microns. The fluorescence component can provide local qualitative and quantitative information about the sample composition elements. Using the X-Y linear stages, the µXRF system provides high resolution (~20 µm) composition mapping and accurate thickness measurements of multilayer samples.