Structural health monitoring of irradiated high-density polyethylene samples with electrical resistance tomography

This work presents preliminary results of a multifunctional lightweight material for radiation sensing and protection. The proposed concept is built with off-the-shelf components: molded high-density polyethylene (HDPE) sheets and a commercial carbon black coating designed as a shield for electromagnetic interference (EMI). The HDPE is a hydrogen-rich lightweight material that is commonly used for radiation protection. The carbon black coating is a non-structural, electrically conductive coating that serves here not only the purpose of structural health monitor, but also protects the underlying HDPE structure. The carbon black-coated area in the HDPE samples was instrumented with electrodes for electrical resistance tomography (ERT), the structural monitoring method that we propose in this work. Two types of radiation (UV-C radiation for 24 h and protons with a 50 Gy dose, lethal to humans) were used separately, as representative of a harsh space environment. Fourier transform infrared spectroscopy (FTIR) was applied to selected samples to determine the presence of chemical damage as a result of the radiation exposure. The results support this innovative proof of concept for further investigation in the area of radiation protection and monitoring.