Volume 67 (2022): Edizione 1 (March 2022)

The spontaneous wetting and drying of flat porous samples of linen, cotton and synthetic textiles were studied using dynamic neutron radiography (DNR). The progress of the wetting process of the media was delineated from the obtained neutron dynamical radiography images. The results of the investigation reveal a non-classical behaviour of kinetics of wicking of these materials. The character of the wetting kinetics is discussed in terms of the fractal character of the tortuosity of fabric capillaries.

Radioisotope applications in industrial process inspection and evaluation using gamma-ray emitters provide otherwise unavailable information. Offering alternative gamma-ray sources can support the technology by complementing sources’ availability and radiation safety. This work proposes to replace gamma-ray from radioisotopes with prompt gamma-ray from the interaction of neutrons with stable isotopes injected into the industrial process or with the structural material of the industrial process equipment. Monte Carlo N-Particle Transport Code (MCNP5) was used to simulate the irradiation of two-phase flow pipes by ²⁵²Cf neutron source. Two simulations were run for each pipe, with and without mixing the liquid phase with the stable isotope ¹⁵⁷Gd. The detected gamma-ray spectra were analysed, and images of the two phases inside the pipes were produced. The images were compared to images obtained from simulations of gamma transmission measurement using ⁶⁰Co. Furthermore, results for prompt gamma computed tomography (CT) were presented and discussed. The studies’ outcomes indicate the potential of prompt gamma-ray to carry out the sealed sources applications of gamma transmission measurements and imaging.