Suppression of blister formation and deuterium retention on tungsten surface due to mechanical polishing and helium pre-exposure
Suppression of blister formation and deuterium retention on tungsten surface due to mechanical polishing and helium pre-exposure
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DOI：
10.1088/0029-5515/45/7/016
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发表时间：
2005-06
期刊：
影响因子：
3.3
通讯作者：
D. Nishijima;H. Iwakiri;K. Amano;M. Ye;N. Ohno;K. Tokunaga;N. Yoshida;S. Takamura
中科院分区：
文献类型：
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作者：
D. Nishijima;H. Iwakiri;K. Amano;M. Ye;N. Ohno;K. Tokunaga;N. Yoshida;S. Takamura
低能氘 (D) 等离子体暴露在钨 (W) 上（ITER 的重要材料）会导致表面形成气泡。气泡的形成会增加微米级粉尘的产生和 D 的保留。气泡的形成很大程度上取决于表面预处理。将氘等离子体暴露在镜面抛光的粉末冶金 W 上，在 500 K 下持续 3 小时，在表面形成直径数百微米的气泡。机械抛光和氦气预曝表面上的气泡形成得到了极大的抑制。与镜面抛光表面相比，机械抛光表面和氦气预曝光表面上的氘保留也减少了。机械抛光表面上气泡形成的抑制效果可维持 50 小时。与镜面曝光3 h（≲200 µm，5 × 1020 m−2）的镜面表面相比，曝光50 h的镜面表面的气泡尺寸和D保留有一定程度的增加（≲500 µm，7 × 1020 m−2），但与曝光时间不成正比。即使在富含气泡的表面上，D 保留的饱和水平似乎也低于 1021 D2 m−2 的数量级。
Low-energy deuterium (D) plasma exposure on tungsten (W), which is an important material for ITER, results in blister formation on the surface. Blister formation increases both micron-sized dust production and D retention. Blister formation depends greatly on surface pre-treatment. Deuterium plasma exposure on mirror-finished powder metallurgy W at 500 K for 3 h forms a blister with a diameter of a few hundred micrometres on the surface. Blister formations on the mechanically-polished and helium-pre-exposed surfaces are drastically suppressed. Deuterium retention is also reduced on both the mechanically-polished surface and the helium-pre-exposed surface compared with that on the mirror-finished surface. The suppressive effect of blister formation on the mechanically-polished surface is maintained for 50 h. The size of blisters and D retention on mirror-finished surface exposed for 50 h increases by some degrees (≲500 µm, 7 × 1020 m−2) compared with that on mirror-finished surface exposed for 3 h (≲200 µm, 5 × 1020 m−2), but is not proportional to the exposure time. The saturation level of D retention even on blister-rich surfaces seems to be lower than an order of 1021 D2 m−2.