Sensors for Harsh Environment: Radiation Resistant FBG Sensor System
Sensors for Harsh Environment: Radiation Resistant FBG Sensor System
复制标题
DOI：
10.1109/jlt.2016.2598666
复制
发表时间：
2017-08-15
影响因子：
4.7
通讯作者：
Grattan, K. T. V.
中科院分区：
文献类型：
--
作者：
Pal, Atasi;Dhar, Anirban;Grattan, K. T. V.
研究了光纤布拉格光栅（FBG）传感器的抗辐射特性，并将其写入光敏光纤中，连接到硅芯抗辐射光纤上，旨在开发一种既适合于恶劣环境下的传感又适合于数据传输的传感系统。石英芯氟下掺杂包层光纤已专门设计和制造本研究使用改进的化学气相沉积技术。关键的波导参数，包括氟掺杂的内包层的宽度已被优化，以获得在1550 nm的工作波长区域的低损耗（< 0.2 dB/km）。还优化了光纤制造工艺，主要是沉积条件，以实现二氧化硅芯层的平滑沉积和烧结，从而使辐射诱导吸收最小化。其结果是，在累积剂量为25兆拉德，剂量率为0.39兆拉德/小时的辐射诱导吸收类似于2.2分贝/公里，在1550 nm已成功实现。为了在恶劣的环境条件下创建有效的传感器系统，这种特殊的光纤连接到在光敏光纤中制造的多个FBG（传感器），然后通过暴露于不同累积剂量的伽马辐射进行广泛的评估。连续监测其相应的布拉格波长位移（BWS）和峰值振幅。有人发现，辐射引起的BWS可以大大减少屏蔽传感器使用不锈钢管。发现温度灵敏度和峰值幅度在暴露于25 MRad的伽马辐射之前和之后基本上没有变化，这表明它们在辐射环境中的温度测量中具有约0.1摄氏度的不确定性的潜在用途。
This paper presents radiation resistant characteristics of fibre Bragg grating (FBG) sensors written in a photosensitive fiber and connected to a silica core radiation resistant optical fibre, aiming to develop a sensor system suitable for both sensing and data transmission in harsh environment. The silica core fluorine-down-doped clad optical fibre has been specifically designed and fabricated for this study using the modified chemical vapor deposition technique. Key waveguide parameters, including the width of the fluorine doped inner cladding have been optimized to obtain a low loss (< 0.2 dB/km) at the operating wavelength region of 1550 nm. The fibre fabrication process, mainly the deposition condition, has also been optimized to achieve smooth deposition and sintering of silica core layers, to minimize radiation induced absorption. As a result, radiation induced absorption of similar to 2.2 dB/ km at 1550 nm under accumulated dose of 25 MRad at dose rate of 0.39 MRad/hr has been successfully achieved. To create an effective sensor system for harsh environmental conditions, this specialty fibre is connected to a number of FBGs (sensors) fabricated in photosensitive fibres prior to their extensive evaluations by being exposed to different accumulated dose of gamma radiation. Their corresponding Bragg wavelength shifts (BWS) and peak amplitudes were continuously monitored. It was found that the radiation induced BWS can be greatly reduced by shielding the sensors using stainless steel tubing. The temperature sensitivity and peak amplitude were found to be largely unchanged before and after exposure to Gamma radiation of 25 MRad which shows their potential use for temperature measurements in radiation environments with an uncertainty of around 0.1 degrees C.