From: utzoo!decvax!genradbo!linus!lemmon Newsgroups: net.physics Title: Re: long superconductors Article-I.D.: linus.2209 Posted: Thu Jan 6 10:30:06 1983 Received: Fri Jan 7 02:18:08 1983 References: sri-unix.4923 I think that the heat flux is very relevant. If the cable can only carry a certain heat flux (even with zero temperature drop), then it can only cool a length of itself limited by the heat leakage per unit length. Beyond that length, the flux at the refrigerator would exceed the carrying capacity of the cable, which would then (probably) cease being superconducting. Rather odd cyclic behavior might occur. In any case, there would be a need for refrigerators every so often. Alan Lemmon