Pulsed-laser ablation of co-deposits on JT-60 graphite tile
Pulsed-laser ablation of co-deposits on JT-60 graphite tile
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DOI：
10.1016/j.jnucmat.2007.04.014
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发表时间：
2007-08
影响因子：
3.1
通讯作者：
Y. Sakawa;D. Watanabe;T. Shibahara;K. Sugiyama;T. Tanabe
中科院分区：
文献类型：
--
作者：
Y. Sakawa;D. Watanabe;T. Shibahara;K. Sugiyama;T. Tanabe
研究了利用20ps-Nd: YAG激光的四次谐波对JT-60开导流瓦上共沉积层的脉冲激光烧蚀。随着激光强度的增加，可以区分出非烧蚀区（NAR）、弱烧蚀区（WAR）和强烧蚀区（SAR）三个区域。从NAR到WAR和WAR到SAR的转变分别发生在激光烧蚀和碳原子强电离的阈值激光强度上。烧蚀过程伴有h2和C2H2的解吸，其他烃类的贡献较小，而H2O的生成较小。在NAR和WAR中，激光照射解吸氢的数量少于在烧蚀体积中保留的氢的数量，而在SAR中，由于烧蚀体积周围区域的氢气热解吸，其数量要大得多。对于氢同位素的烧蚀脱除，SAR具有较高的脱除效率和较少的烃类生成量。
Pulsed laser ablation of the co-deposits on a JT-60 open-divertor tile using the fourth harmonic of a 20ps-Nd: YAG laser has been investigated. With increasing the laser intensity, three regions, non-ablation region (NAR), weak-ablation region (WAR), and strong-ablation region (SAR) were distinguished. Transition from NAR to WAR and WAR to SAR occurred at the threshold laser intensity for laser ablation and that for strong ionization of carbon atoms, respectively. The ablation accompanied desorption of H2and C2H2, with minor contribution of other hydrocarbons, while production of H2O was small. In NAR and WAR the number of the hydrogen desorbed by the laser irradiation was less than that of hydrogen retained in the ablated volume, while in SAR it was much larger, owing to thermal desorption of hydrogen gas from the region surrounding the ablated volume. For the ablative removal of hydrogen isotopes, SAR is more desirable because of higher removal efficiency and less production of hydrocarbons.