Cryogenic cable dielectrics

In recent years more and more attention has been directed to the development of electrical equipment operating at cryogenic temperatures. The application of superconductors in high field magnets is well known, but superconductivity appears to be less advantageous for devices such as cable and transformers. Instead, the low resistance of copper and particularly of very pure aluminum at liquid hydrogen temperatures may prove to be very useful. To capitalize most fully on the cryogenic ambient, it seems appropriate to consider the advantages in respects other than decreased resistance in the conductors. So far, improvement in magnetic characteristics does not seem likely at cryogenic temperatures. However, cryogenic insulation systems do appear to offer potential advantage, particularly at high voltages.