双包层紫外光纤伽马辐照效应实验研究

摘要

双包层大芯径紫外石英光纤具有高的传输效率和耐辐照性,在核辐射场信号传输与测量中有良好的应用前景.但在核辐射场中,光纤受辐照会产生发光和诱导损耗,影响测量精度和准确度.为此,建立了光纤辐照损耗和发光光谱测量系统及方法,对芯径为0.2、0.4和0.6 mm石英光纤在辐照剂量率为0.0536 Gy/s的稳态60 Co伽马射线源上进行了测量.实验结果表明:芯径越大,光纤辐照产生的附加损耗越小;辐照附加损耗并非与总剂量呈正比,随着辐照时间和总剂量的增加,损耗值增量逐渐减小;发光和损耗与光的波长有关,短波区光纤发光强度和损耗较长波区大;实验测量得到了0.6 mm光纤在300~600 nm的发光光谱,发光强度约为10-13 W·s/(Gy·m);相同时间内,不同波长辐照恢复效果不同,长波长损耗小,较快恢复到辐照前光纤传输效率,而短波长损耗大,恢复较慢.%The large core pure quartz fiber with double-clad offers an attractive alterna-tive to transmit light pulse signal in irradiation fields .But fibers can be induced to produce luminescence and absorption by irradiation ,and this makes the real signal dete-riorated .In order to evaluate these effects ,the fibers of core diameters of 0.2 ,0.4 and 0.6 mm were researched in 60 Co source with irradiation dosage rate of 0.0536 Gy/s . The experimental results show that the irradiation induced loss decreases with core diameter increasing ;the additional loss is not in direct proportion to the amount of total dosage;with total dosage increasing ,the additional loss increases slowly and gradually reaches stable value;the amounts of illumination and loss at short wavelength are more than those at long wavelength in 300-600 nm wavelength ,and luminous intensity is 10-13 W · s/(Gy · m) .In addition ,the recovery of these fibers is observed .