To verify the feasibility of Brillouin optical time domain reflector (BOTDR) applied in space station, three kinds of commercial fibers, YOFC fiber (about 1 km), Corning fiber (about 1 km) and Fujikura fibers (about 1.5 km), have been radiated by Co60 in radiation experiment. Based on the Brillouin Gain Spectrum (BGS) along sensing fiber, we analyze power curve of Brillouin backscattered light, Brillouin Frequency Shift (BFS) along sensing fiber and spatial resolution carefully. The results indicate that radiation has little effect on BFS when signal-to-noise ratio (SNR) is large enough. However, since radiation will lead to radiation-induced attenuation, the amplitude of BGS will decrease accordingly. And if the SNR becomes small enough, the accurate BFS cannot be obtained. For the stressed fiber section of BOTDR, the result shows that radiation has little effect on the strain coefficient at the total radiation dose of 200 Gy, but radiation will deteriorate the spatial resolution of BOTDR with the increase of radiation dose. These results are good references for the introduction of BOTDR to space station.

中文翻译：

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低空间辐射剂量下对 BOTDR 的辐射效应研究

为验证布里渊光时域反射器（BOTDR）在空间站应用的可行性，长飞光纤（约1公里）、康宁光纤（约1公里）和藤仓光纤（约1.5公里）三种商用光纤在辐射实验中用 Co60 辐射。基于沿传感光纤的布里渊增益谱（BGS），我们仔细分析了布里渊背向散射光的功率曲线、沿传感光纤的布里渊频移（BFS）和空间分辨率。结果表明，当信噪比 (SNR) 足够大时，辐射对 BFS 的影响很小。但是，由于辐射会导致辐射引起的衰减，因此 BGS 的幅度会相应减小。如果 SNR 变得足够小，则无法获得准确的 BFS。对于 BOTDR 的受力光纤部分，结果表明，在总辐射剂量为200 Gy时，辐射对应变系数的影响不大，但随着辐射剂量的增加，辐射会降低BOTDR的空间分辨率。这些结果为 BOTDR 引入空间站提供了很好的参考。