抄録
It is well known that water-tree propagation in XLPE cable is significantly influenced by inorganic impurities in water. Therefore, we investigated both changes in concentration and deviation of isotopic content of inorganic elements in XLPE samples by water-tree experiments under clean environment. The concentration of several kinds of elements, e.g., Li, Na, Mg, Al, K, Ca, Fe, Ni, Pb and Bi, in water-treed sample showed anomalous increase or decrease dependent on cation (K+, Na+ or Ag+) in water solution compared with blank or original sample. Furthermore, the isotopic content of Zn deviated over 6% from natural abundance. These results suggest that water-tree propagation is concerned with unknown physical or electro-chemical reactions.
