Impact of collodion thickness on fission track generation within Lexan employed for nuclear forensic analyses

Abstract We report results from a computational study of fission track damage within a Lexan substrate caused by 235 U suspended within a collodion film of varied thickness. MCNP6.3 was used to model energy deposition and displacements per atom within a Lexan film coated by a film of collodion, located within the air-filled 6 inch dry tube of a TRIGA reactor. The collodion layer was varied between 20 and 100 μm thickness, resulting in an 8.8% difference in energy deposition and 12% difference in displacements-per-atom within the Lexan substrate. These findings indicate that collodion adhesive thickness has a moderate impact on the localized energy deposition and damage environment within Lexan. This sensitivity can inform high-precision forensic reconstructions where damage quantification is critical. Graphical abstract