In-situ radio-luminescence from sapphires under fission reactor irradiation

Radio-luminescence from the sapphire was detected in-situ under the reactor irradiation using the silica core optical fiber. The radio-luminescence peaks at 420, 690, and 860 nm, and broad band in 700-1200 nm were identified. However, these radio-luminescence peaks and band became obscure as the reactor power went up, due to the increase of the specimen temperatures and to the interference of the strong radio-luminescence from the silica core optical fiber itself. The effect of the applied electric field on the radio-luminescence was studied. Change was observed due to the electric field but it was very small. Further study and a better-controlled experiments will be needed to clarify the effect.