Neutron effects on γ-ray dosimetry

Pre-neutron irradiation affects the γ-response of soda-lime silica glass measured optically. This effect was found to be higher at lower neutron fluences, decreasing for increasing neutron fluence and reaching values similar to that for pure γ-irradiation. This effect is dependent on the amount of γ-dose following neutron exposure, i.e. the higher the γ-dose the lower the effect of neutron pre-exposure. Neutrons alone were found to have no optical effect. The total change in optical density as well as the spectra of samples exposed to neutrons, gamma and neutrons plus gamma has been measured and used to explain the effect of neutrons on the γ-response of silica glass.