Possibility of using real time digital neutron radiography to study the evaporation of water in porous materials

The study of the process of absorption and evaporation of fluids in porous media is of particular importance in sciences such as geology, civil engineering, environment, etc. Neutron radiography is one of the most precise methods for investigation of the mentioned processes. Due to the high cross-section of the interaction of thermal neutrons with hydrogen, precise investigation of absorption and evaporation of fluids containing hydrogen, such as water, oil, etc., is possible. In the present work, using the real-time neutron radiography technique, the vaporization of water from a porous building sample at 10 °C in the laboratory was investigated. For this purpose, a building brick was immersed into water for 24 hours, and then was placed in front of the neutron beam. During 145 minutes of reactor operation, 30 images were recorded with a 5 minutes interval from the wet sample. The obtained images showed that using the utilized technique, the distribution variations and volumetric water content inside the sample are well visible. Also, the results indicated that the volumetric water content in the sample was evaporated with a rate of 3.94×10-4 percent per seconds in the laboratory environment.