POLY(BENZIMIDAZOLE) AS INSULATOR FOR SUPERCONDUCTORS

We have developed a poly(benzimidazole) (PBI) insulator for supercondu ctors for the Superconducting Supercollider. The PBI compounds used fo r the insulator matrix are expected to be a superior material with hig h radiation resistance, high flexural modulus and high thermal resista nce. On superconductor wire, PBI coating is superior as an insulator t o Kapton-film wrapping. In particular, after electron-beam irradiation of 12 000 Mrad of a Cu/PBI system, the radiation-dose resistance of t he PBI-coated insulator was evaluated as 4.4 kV of the test voltage (i nitial 4.8 kV), whereas that of a Kapton-wrapped conductor was 2.5 kV after 6000 Mrad of irradiation.