Nikon Metrology

The Scan of June – Discover the details of a high voltage breakdown pathway

Computed tomography, X-ray and CT Inspection

This month, James Finch (Applications Engineer) scanned a rotating 450kV X-ray target drive tube.

The drive tube governs the rotation of the target and supplies coolant to it while isolating the high voltage target from the rest of the source. The tube scanned was from a customer high voltage component that they brought it to us after suspecting breakdown due to not following the maintenance cycle, and therefore had contamination build up within the coolant. This led to a charge build up within the coolant and the drive tube suffered a high voltage breakdown as a result.

 

     

The breakdown pathways were 3D rendered in Volume Graphics VGStudioMAX 3.5, using the ‘Phong’ renderer to show the ‘background’ (air) rather than the ‘material’ (drive tube) of the scan. The 2D views were obtained by utilising the ‘thick slab’ feature in order to project the pathways onto a single side view.

     

The X-ray CT scan was acquired at a voxel resolution of 11.3µm, while using 60kV potential and 9 Watts X-ray power. The scan was acquired using a Nikon XT H 225, which houses a Nikon 225kV microfocus X-ray source, coupled with a Varex 4343-CT flat panel detector.  For this scan the detector acquired 6000 projections at an exposure of 2000ms (which is quite a long scan compared to the speed of our X-ray CT scans).