Verifying Neutron Tomography Performance using Test Objects

In an effort to provide a standardized method to quantify the imaging capabilities of neutron imaging beam-lines worldwide, we propose a set of test objects for neutron tomography. The test objects are designed to quantify spatial resolution and material contrast in tomograms. The resolution samples aim at detecting a thin film embedded in a different material. Two samples with complementary material compositions are proposed for this purpose. The contrast sample has several insets of different materials. The measurements are proposed to be done using both radiography and tomography. The image processing methods needed to evaluate the performance of the reconstructed data are presented. The methods are automated to avoid subjective decisions by persons who evaluate the data. Experimental data to demonstrate the test objects and their analysis methods were acquired with the cold neutron imaging beam-line, ICON, in comparison with data from the thermal neutron facility, NEUTRA at Paul Scherrer Institut, Switzerland. This is a first initiative and is open for discussion among the participants to further improve the evaluation procedure.