Neutron radiography and its image resolutions

Neutron radiography (NR) is widely applied especially for non-destructive inspection of industrial products. An outline of NR technique is given in this report with few examples of industrial applications. The quality of a NR image depends on many factors. The values of L, D, and L/D are main factors to define a geometrical unsharpness of NR images. A device for accurate measurements of those parameters is proposed and fabricated. Degree of confidence is estimated for measurements of those parameters in detail. Values of L, D, and L/D are measured for our NR facilities with different geometrical conditions by use of the device and the values are compared to the designed values. The quality of the NR image also depends on an inherent unsharpness of its imaging device. The inherent unsharpness is measured as an edge spread function (ESF) and a modulation transfer function (MTF) is derived from the ESF with a technique of the discrete fast Fourier transform (DFFT). Results are compared to theoretically calculated MTF. (author)