Abstract: A superconducting coil having an elongated longitudinally extending first hollow metallic housing and adapted to provide a cooling passage of liquid helium therein. At least one superconducting metallic conductor is disposed within the housing which is surrounded with an electrical and thermal insulating material. An elongated second metallic housing surrounds the inner insulated structure and is adapted to be mechanically connected to similar structure when arranged into a coil structure having a predetermined configuration. A method of manufacture is also disclosed as well as how the novel integrated coil and case structure is advantageously employed in an improved fusion reactor structure and Magneto Hydrodynamic Magnet Structure.