An investigation into the possibility of performing radiography with gamma rays emitted from water made radioactive by irradiation with 14 MeV D-T fusion neutrons

Most conceptual designs for D-T fusion reactors incorporate water cooling. However, the water becomes temporarily radioactive, mainly from 16O(n, p)16N reactions induced by 3H(d, n)4He fusion neutrons. Reported studies of this phenomenon generally examine various related detrimental effects. The present investigation explores a potentially beneficial application of this radioactivity for radiography. This is accomplished using 6.129 and 7.115 MeV photons generated by the decay of 7.13 s 16N. The concept is demonstrated here by using D-T fusion neutrons from a neutron generator to activate water. A simple radiography apparatus was constructed by circulating pure water between the accelerator target region and a remote location where photon transmission measurements were conducted using a collimated photon source and detector arrangement. Four objects with distinct features were examined in this work. These measurements demonstrated that features like hidden holes and discontinuities in atomic number could be identified easily by observing variations in photon transmission. Spatial resolutions consistent with the geometry of this apparatus were observed in all instances. This paper also discusses advantages this technique might offer when applied in an actual D-T fusion reactor environment.