Introduction and General Survey

Abstract

Throughout this book the term “high magnetic field” will refer to fields well in excess of 50 kOe (kilo-oersted), or in other words fields above those which can be reached by conventional iron-cored electromagnets. First, it is necessary to state why it is worth writing about the generation of very strong magnetic fields and what they can be used for. Techniques for generating strong fields have been improving steadily over the years, the most recent step forward being the discovery of superconductors which have already been used to generate fields well above 100 kOe and which have the potential of going to considerably higher fields. Powerful fields, when once established in a superconducting solenoid, can be maintained with no power dissipation other than that required to maintain the necessary low temperature, and high magnetic fields appear possible without the need for cooled solenoids dissipating megawatts of power or for massive iron-cored systems. Thus, technical processes demanding high fields which have hitherto been ruled out on economic grounds now become feasible, and in fundamental studies also the more extensive use of magnetic fields seems possible.