Characterization of the Photoneutron Flux Emitted by an Electron Accelerator Using an Activation Detector

Abstract : Electron accelerators are intense photoneutron sources for nuclear waste packages characterization and homeland security applications. Moreover, when considering medical accelerators, photoneutrons can cause secondary cancers for patients and also expose hospital staff to deactivation gammas after the irradiation. In this study, we investigate photoneutrons properties according to average emission intensity, energy spectrum and spatial distribution. The latter parameter was measured using an activation detector and the other two parameters were determined by simulation, and then, evaluated by comparing absolute activation simulations and measurements. Our methodology was applied to characterize the photoneutron flux generated by two electron accelerators. Our study has shown that there is a strong probability for photonuclear cross-sections to be undervalued in the energy range studied.