Neutron imaging based on transfer foil activation and COTS CMOS image sensors

In this paper we present a method for obtention of neutron images with Commercial-Off-The-Shelf (COTS) CMOS image sensors through the activation of indium foils. This detection method has been designed specifically for the acquisition of thermal and epitermal neutron images in mixed beams with a high gamma flux, and also for the study of high radioactive samples that are usually placed into research reactor pools. We also present a technique to obtain multi-spectral neutron images taking advantage of the high neutron absorption cross-section of this material in the thermal energy range, as well as around the 1.45 eV resonance. Measurements performed in a neutron beam of the RA6 nuclear research reactor located in Bariloche, Argentina, confirm the capability of the proposed technique.