A novel approach to radiographic image resolution gauge fabrication

A resolution gauge was fabricated for measuring the spatial resolution of radiographic imaging systems. Silicon wafers, 100 mm 〈1 0 0〉, were patterned using standard contact lithography and the patterned features were etched using deep reactive ion etching (DRIE). The smallest features were 5 μm wide line pairs. The resulting etched trenches included aspect ratios of up to 10:1 and were 40.6±0.2 μm deep. The etch rate was 2.7 μm/min for the reported etch depth. A Gd₂O₃ nanopowder was dispersed into a slurry using Darvan C and water as the dispersant and solvent, respectively. A rapid infiltration method was used to fill the etched trenches with the slurry. Neutron and X-ray radiographs of the resolution gauge and the results demonstrate that the prototype gauge would be a suitable standard for measuring the spatial resolution of both X-ray and neutron radiography systems.