Refrigeration requirements for future superconductive energy related applications

A survey of the refrigeration needs of proposed superconductive energy related technologies is presented. The devices which are considered include: superconductive magnetic energy storage, magnetically confined fusion reactors, superconducting power transmission lines, magnetohydrodynamic units, and superconducting turbine generators. For each system, the cryogenic helium inventory, makeup and refrigeration requirement are discussed. The survey consists of a compilation of estimates from existing system studies and private communications with various workers in the field. A comparison between future and current state-of-the-art refrigeration is included. (author)