掺锗石英光纤的稳态和瞬态γ辐射效应研究

开展了掺锗石英光纤在1.0×10~(-4)~0.5Gy(Si)/s剂量率下的稳态γ辐照实验和10~6~10~9 Gy(Si)/s剂量率下的瞬态γ辐照实验。结果表明:光纤辐射感生损耗与辐照总剂量呈饱和指数关系,与色心浓度微分方程推导出的结论相一致。在辐照总剂量相同的情况下,光纤辐射感生损耗随辐照剂量率的增大而增大。辐照期间有光注入较无光注入时的光纤辐射感生损耗低,证实了光褪色效应的存在。对实验用650、850和1 310nm 3个波长,光纤辐射感生损耗随波长的增大而减小。与光纤稳态辐射感生损耗相比,光纤瞬态辐射感生损耗要大得多;光纤瞬态辐射感生损耗峰值与脉冲总剂量呈线性关系,这与饱和指数关系在低剂量下的泰勒展开近似一致。

Effect of Steady-state and Transient γ Radiation on Ge-doped Quartz Optical Fiber

Ge-doped quartz optical fibers were irradiated by steady-state γ with dose rate of 1.0×10^-4-0.5 Gy(Si)/s and transient γ with dose rate of 10⁶-10⁹ Gy(Si)/s. The results show that the radiation induced loss in optical fiber satisfies saturate exponential relationship with total dose, which agrees with the conclusion developed from color center concentration differential equation. The radiation induced loss in optical fiber increases with dose rate at a given total dose. The photobleaching effect was validated by the result that radiation induced loss in optical fiber is less with transmitted light during irradiation. The radiation induced loss in optical fiber decreases with increasing wavelength from 650 to 1310 nm. The transient radiation induced loss in optical fiber is much larger than steady-state radiation induced loss. The peak magnitude of transient radiation induced loss in optical fiber is linear with pulse total dose, which agrees with Taylor expansions approximation of saturate exponential relationship at low total dose.