Simultaneous heating and compression of irradiated graphite during synchrotron microtomographic imaging
Simultaneous heating and compression of irradiated graphite during synchrotron microtomographic imaging
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同步加速器显微断层成像过程中同时加热和压缩辐照石墨
DOI：
10.1088/1742-6596/849/1/012021
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Bodey A
中科院分区：
文献类型：
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作者：
Bodey A
核石墨在裂变发电站中用作中子慢化剂。为了研究在使用过程中发生的微观结构变化，首次采用原位加热和压缩的X射线显微断层扫描技术对其进行了研究。这项实验是第一次在钻石光源同时加热和机械加载放射性样品，并代表了在钻石-曼彻斯特成像支线I13-2对放射性物质的第一次研究。制定了工程方法和安全协议，以确保辐照石墨在德本10kn敞开式框架试验台中同时压缩到450N，并使用双聚焦红外灯加热到300℃时的安全容器。安全密封的核心是一个双重密封容器，它防止空气中的颗粒物逃逸，同时能够通过可移动的冲头进行压缩，并将红外线传输到样本。通过热电偶读数进行现场温度测量。在加热和压缩过程中，样品同时旋转并用多色X射线成像。由此产生的显微断层图像正在通过数字体积相关进行研究，以深入了解热膨胀系数和微结构如何受到辐射历史、载荷和热量的影响。这些信息将是提高石墨降解模型准确性的关键，这些模型为发电站的安全裕度提供信息。
Nuclear graphite is used as a neutron moderator in fission power stations. To investigate the microstructural changes that occur during such use, it has been studied for the first time by X-ray microtomography with in situ heating and compression. This experiment was the first to involve simultaneous heating and mechanical loading of radioactive samples at Diamond Light Source, and represented the first study of radioactive materials at the Diamond-Manchester Imaging Branchline I13-2. Engineering methods and safety protocols were developed to ensure the safe containment of irradiated graphite as it was simultaneously compressed to 450N in a Deben 10kN Open-Frame Rig and heated to 300 C with dual focused infrared lamps. Central to safe containment was a double containment vessel which prevented escape of airborne particulates while enabling compression via a moveable ram and the transmission of infrared light to the sample. Temperature measurements were made in situ via thermocouple readout. During heating and compression, samples were simultaneously rotated and imaged with polychromatic X-rays. The resulting microtomograms are being studied via digital volume correlation to provide insights into how thermal expansion coefficients and microstructure are affected by irradiation history, load and heat. Such information will be key to improving the accuracy of graphite degradation models which inform safety margins at power stations.
DOI：
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发表时间：
2016
期刊：
影响因子：
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作者：
K. McNally;M. Fahad;E. Tan;N. Warren;G. Hall;B. Marsden
通讯作者：
B. Marsden