Air Core Cryogenic Magnet Coils for Fusion Research and High-Energy Nuclear Physics Applications

Abstract

In the fields of controlled fusion research and high-energy nuclear physics it is becoming evident that means for the efficient generation of very high magnetic fields must be sought. Since ferromagnetic materials are of no help at the required fields of 10⁵ gauss, one can only rely on the use of air core coils, so that the fields which can be reached depend only on the ampere-turns achievable and simple geometrical factors. In this case the limitations on attainable fields usually come down to a question of available electrical power, or, more fundamentally, to limitations imposed by heating of the coil conductors and problems of heat transfer within the coil. For laboratory — sized magnets, the limit is reached in magnets such as the Bitter magnet, where the ultimate limit is nearly reached in power density and heat transfer while achieving steady fields of 10⁵ gauss in volumes of the order of 1 liter.

Work done under the auspices of the U.S. Atomic Energy Commission.