Transmittance measurements of cold neutrons for some materials by means of neutron radiography

We examined cold neutron radiography (CNR) to determine its characteristics with respect to the ability to obtain the quantitative measurements. In order to describe the complicated transmission phenomena in CNR, a thickness dependent attenuation coefficient μ(t) is introduced instead of an average attenuation coefficient. A simple function using a linear approximation model to μ(t) is proposed to express transmission curves in CNR. This function agreed well with the experimental data for materials having deep and shallow Bragg cutoffs and for a 1 /ν dependent material. Thus, the linear approximation to μ(t) is effective for describing the transmission phenomena in CNR.