Characterisation of X-ray source for X-ray computed tomography for dimensional metrology

The National Physical Laboratory along with University College London are working towards characterising the errors associated when using X-ray computed tomography (XCT). Throughout the imaging process a difference in the quality of the images is seen leading to a change in the image background, this could in turn lead to incorrect threshold values being set and lead to errors in dimensional measurements. Figure 1 highlights the variation of the total intensity on the detector. The work presented in this poster is focused on the characterisation of the X-ray flux and concentrates on its stability throughout image acquisition and the spatial distribution across the cone beam. Experimental data was collected to quantify the variations both temporally and spatially and the results discussed.