Conducting cored wire

The most inner layer of the high voltage cable. Each core is made up of a number of thin copper wires, and the insulated skin is outsourced. Insulation requirements: withstand 50Hz, 1000V alternating current test 5min does not break. The two core is specially used for single focus X-ray tube, and the three core is specially used for double focus X-ray tube. (there is an insulated skin between the core lines)