An investigation of the effect of cross-linking in polyethylene through space charge and luminescence measurements

Space charge accumulation and changes in the nature of trapping sites are investigated going from low density (LDPE) to cross-linked (XLPE) polyethylene. Two different types of techniques were used: the pulsed electro-acoustic (PEA) technique to detect the net space charge under dc stress and luminescence experiments to probe the trapping sites. It is found that the chemical and/or structural modifications introduced by the cross-linking process itself control the charge storage in XLPE.