Some observations on artificial cavities in a cross-linked polyethylene

An experimental study of artificial cavities in cross-linked polyethylene (XLPE) was conducted, and results are compared with those for other materials. Discharge evolution vs. time in XLPE cavities (both sealed and open) is reported. An examination of discharge characteristics vs. time shows an abrupt decrease of discharge frequency during the first 30 min; their number reaches a steady state but an extinction is never observed. This behavior is interpreted in terms of an increase in the cavity-wall conductivity or in terms of gas-pressure changes.<
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