Thermal Response of Tritiated Codeposits from JET and TFTR to Transient Heat Pulses
Thermal Response of Tritiated Codeposits from JET and TFTR to Transient Heat Pulses
复制标题
JET 和 TFTR 氚共沉积物对瞬态热脉冲的热响应
DOI：
10.1238/physica.topical.103a00034
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发表时间：
2002
期刊：
影响因子：
2.9
通讯作者：
S. Willms
中科院分区：
文献类型：
--
作者：
C. Skinner;N. Bekris;J. P. Coad;C. Gentile;A. Hassanein;R. Reiswig;S. Willms
在微观尺度上研究了高热流与面向等离子体部件的相互作用。来自连续波钕激光器的光束在DT等离子体操作后从TFTR和JET取回的石墨和碳纤维复合材料瓦的表面上高速扫描。瓷砖表面有一层无定形氢化碳，这是在等离子体操作过程中共沉积的，激光扫描释放了80%以上的共沉积氚。共沉积物的温升远高于制造材料的温升，并显示出延长的时间历史。峰值温度变化剧烈（例如1436°C与>2300°C相比），表明基底的热导率变化很大。数字显微镜在与激光相互作用之前、期间和之后对共沉积物进行成像，并在相互作用期间显示出100微米尺度的热点。热通量在混合Be/C存款上产生珠状图案。热脉冲持续时间为100毫秒的顺序导致脆性破坏和材料损失的表面，而100毫秒的持续时间表现出最小的变化，共沉积。这些结果表明，可靠的预测的沉积面积的响应异常的事件，如ELMs和中断在下一步设备需要基于实验与托卡马克产生的codeposits。
High heat flux interactions with plasma facing components have been studied at microscopic scales. The beam from a continuous wave neodymium laser was scanned at high speed over the surface of graphite and carbon fiber composite tiles that had been retrieved from TFTR and JET after DT plasma operations. The tiles have a surface layer of amorphous hydrogenated carbon that was codeposited during plasma operations and laser scanning has released more than 80% of the codeposited tritium. The temperature rise of the codeposit was much higher than that of the manufactured material and showed an extended time history. The peak temperature varied dramatically (e.g. 1436°C compared to >2300°C) indicating strong variations in the thermal conductivity to the substrate. A digital microscope imaged the codeposit before, during and after the interaction with the laser and revealed 100-micron scale hot spots during the interaction. The heat flux produced a pattern of beads on a mixed Be/C deposit. Heat pulse durations of order 100 ms resulted in brittle destruction and material loss from the surface, whilst a duration of ≈ 10 ms showed minimal changes to the codeposit. These results show that reliable predictions for the response of deposition areas to off-normal events such as ELMs and disruptions in next step devices need to be based on experiments with tokamak generated codeposits.