TY - JOUR
T1 - Surface Modification of Tokamak Fixed Limiter Used in High-Field Tokamak TRIAM-1
AU - Tokunaga, Kazutoshi
AU - Fujiwara, Tadashi
AU - Miyamoto, Yoshio
AU - Muroga, Takeo
AU - Yoshida, Naoaki
AU - Itoh, Satoshi
AU - Group, Triam
PY - 1990
Y1 - 1990
N2 - The surface morphology and composition changes of a Mo fixed limiter used in the High-Field Tokamak TRIAM-1 after about 70,000 hydrogen plasma discharges have been investigated by means of optical microscope, SEM-EDS and AES. Significant difference in surface damage is observed between the electron drift side and the ion drift side. The damage on the electron drift side is characterized by melting, cracking, cone-like protuberance, droplet, eutectic and impurity accumulation. This is considered to be caused by the overlapped effects of the heat load from the plasma, which decreases with increasing distance from the plasma center, and the impurity accumulation which originated from the stainless steel vacuum vessel and the limiter itself. The kinds of damage on the ion drift side are melting due to arcing, sputtering, blistering and color change of the surface due to impurity accumulation. The distribution of these damages changes with the distance from the limiter edge. The damage observed on the ion drift side is considered to be caused by the synergistic effects of sputtering due to ion bombardment, impurity accumulation and heat load due to arcing.
AB - The surface morphology and composition changes of a Mo fixed limiter used in the High-Field Tokamak TRIAM-1 after about 70,000 hydrogen plasma discharges have been investigated by means of optical microscope, SEM-EDS and AES. Significant difference in surface damage is observed between the electron drift side and the ion drift side. The damage on the electron drift side is characterized by melting, cracking, cone-like protuberance, droplet, eutectic and impurity accumulation. This is considered to be caused by the overlapped effects of the heat load from the plasma, which decreases with increasing distance from the plasma center, and the impurity accumulation which originated from the stainless steel vacuum vessel and the limiter itself. The kinds of damage on the ion drift side are melting due to arcing, sputtering, blistering and color change of the surface due to impurity accumulation. The distribution of these damages changes with the distance from the limiter edge. The damage observed on the ion drift side is considered to be caused by the synergistic effects of sputtering due to ion bombardment, impurity accumulation and heat load due to arcing.
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U2 - 10.3327/jnst.27.333
DO - 10.3327/jnst.27.333
M3 - Article
AN - SCOPUS:85024349160
VL - 27
SP - 333
EP - 342
JO - Journal of Nuclear Science and Technology
JF - Journal of Nuclear Science and Technology
SN - 0022-3131
IS - 4
ER -