Fast neutron detector based on vertically aligned carbon nanotubes

The unique physical properties of carbon nanotubes have spurred numerous applications across various fields. In this study, we investigate their electrical properties to develop a detector for fast neutron flux measurement. Previous research has demonstrated their potential in dosimetry for thermal neutrons and gamma radiation, using random networks of carbon nanotubes. For the measurement of fast neutron flux, we utilize vertically aligned multi-walled carbon nanotubes and monitor the changes in their electrical resistance under neutron irradiation. The vacancies generated in the nanotube structure due to irradiation directly affect their electrical properties, allowing us to deduce the neutron flux from the variation in resistance. Future fusion reactors, such as ITER, are expected to generate intense neutron fluxes in high-temperature environments. These fluxes are challenging for traditional detectors, which tend to degrade quickly under such conditions. Carbon nanotube carpets, with their low density reduce the number of interactions caused by neutron irradiation, thereby extending the device’s operational lifetime. Here the simulation shows that neutron irradiation induces local damages to the molecular structure of the carbon nanotubes. A first test at the CABRI research reactor (CEA Cadarache) has demonstrated the viability of the project.