Neutron irradiation of flint glasses for optics in ITER

Six types of the commercial Ce-doped flint glasses have been irradiated in a nuclear reactor up to fluencies of the fast neutrons (E > 0.1 MeV) within the range of 1012 − 1016 n/cm2. F108 and TF200 types have demonstrated the most prominent results. F108 type has a high transmittance in the visible region and a sufficient radiation hardness to be recommended for use in the port cell. TF200 type has a limited spectral range, but it has shown the best radiation hardness at a fluence of 1016 n/cm2. It can be used in the interspace area if a low transmittance in the violet-blue region is not an issue.