Charge injection into cross linked polyethylene studied by thermally stimulated depolarization

The authors present some initial results of a thermally stimulated depolarization (TSD) study of charge injection into three different types of cross-linked polyethylene (XLPE), DC-polarized at room temperature and heated to 90°C. The three types of XLPE samples were: (1) type A, containing dicumyl peroxide (DCP) with a PE:DCP weight ratio of 100:2; type B, which is cross-linked using silane, the gel content and thickness being 52.7 wt.% and 50 μm, respectively; and type C, which is cross-linked by electron beam irradiation at an accelerating voltage of 150 kV and which has a gel content and thickness of 55 wt.% and 50 μm, respectively. Type A material seems to possess a much greater concentration of electron traps emptying between 20 and 90°C than either type B or type C material