Abstract: "Fast neutron effects on a widely used x-ray film have been investigated. The neutron flux was provided by the (d, t) reaction of a Cockcroft-Walton accelerator. Integrated exposures to 10-10 n/cm-2 were given the film. It was found that perturbations on film that were pre-exposed to Co-60 gamma rays from 10 to 2000 r were negligible. Simultaneous exposure of neutrons plus gammas also indicated negligible effect on the film insofar as the gamma dose was concerned."