A friend is an electrician who works mainly on intallations at factories, etc. He has a beverage coaster made from a thin cross-section of a "primary" cable, the kind that brings power into the plant. It has a central conductor area of many strands of heavy-gage wire, then an insulating sheath of something rubbery that looks sorta like that red HV silicone rubber, then a very thin metallic layer which he called a "semiconductor shield" before the final insulating jacket.
I tried to find out exactly what he meant by "semiconductor" in this context because I couldn't picture silicon or germanium, for example, being made into a flexible foil. (Well, maybe not *too* flexible, since the cable was several inches across!) He said he really didn't know about such things, but that the layer was supposed to reduce the magnetic fields from around the cable, which otherwise were a problem at the high voltages and currents involved. (Which he also didn't know the levels of.)
Anyone familiar with this technology?
Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time AnalysisHome of DaqGen, the FREEWARE signal generator