Neutron radiation effect on carbon-loaded polyethylene

This work aims to study the changes in the electrical conductivity of carbon-loaded polyethylene after neutron irradiation. The material is a polymer-based semiconductor and it was used to evaluate the neutron flux in a research nuclear reactor. The main advantage with this type of semiconductor concerns about that the composite itself is not a material that bring high neutron activation. Such a feature could allow for measuring the neutron flux in real time with the advantage that it is a low cost material. Samples in triplicate with identical geometries were prepared and irradiated at different time intervals in order to evaluate the material response to neutron radiation in function of its electrical property. The method of measurement is based on the voltage yielded when a high precision ultra-low constant current is passing through the material. The results show that if this polymer based semiconductor is submitted to a neutron flux from a nuclear reactor it presents a systematic variation in its electrical resistance and one can conclude that this material can be used as a neutron sensor. (author)