Design and fabrication of highly stabilized close-packed superconducting solenoid

The highly stabilized superconducting solenoid has been fabricated successfully by the dry winding method with the appropriate design of former and ground insulators. In this work the unexpected decrease of quench current was remarked as the index of the instability in the superconducting solenoids because it becomes a serious problem in practical application. The change of the contact condition between the former and the winding was thought to induce the instability therefore the optimization of the contact condition was tried. The former with high thermal contraction and high rigidity and the ground insulator coated with the release film were selected for the solenoid design. It was found that the highly stable superconducting solenoids could be designed and fabricated by this selection.