The superconducting wire can transport more current compared with that of the normal metal because of its superconductive characteristics. To generate the high magnetic field, the high transport current in the coil or many turns of the coil is needed. In the normal wire, many turns are needed because of the limitation of transport current, and this increase of turns can create a huge magnet system. By using the normal metal, the generation of the high magnetic field more than 3 T is impossible. Superconductor can be only alternative to the generation of the high magnetic field above 3 T.
High magnetic fields and the industrial applications of this technology are rapidly developing. In case of MRI and NMR, as the magnetic field become higher, the resolution becomes better. This better resolution in MRI creates the capacity to see the fine nervous system and analyze an ill-defined disease. The ultra high magnetic field NMR above 23.5 T supports the possibility to analyze the structure of protein, whose result can be used in the development of new pharmaceuticals.
The goal of this dissertation is to perform and develop of the hybrid (LTS/HTS) magnet for the application of high magnetic field. The fundamental design process and the necessary technologies to design the superconducting magnet are mentioned in this dissertation. Each factors such as the electromagnetic field analysis, the magnet stress, the winding method was discussed and analyzed by numerical and experimental methods using various test models. Also, the protection methods of the LTS magnet and the HTS coil are enumerated. The diode circuit was experimented in liquid helium for protecting the LTS background magnet. The active quench protection using voltage detection was adapted to the HTS insert coil. The study on the no insulation winding which can be a new and effective protecting method was also conducted.
The LTS background magnet for applying magnetic fields externally and the HTS insert coil were fabricated based on the designed result and tested. The prototype hybrid magnet was manufactured and tested to verify the feasibility of the design method and the fabricating method. The magnetic field of 4.32 T at the center was obtained without quench. The hybrid magnet of 10 T level was designed and manufactured based on the proposed process, and tested in the liquid helium environment. After several quench states, the magnetic field of 10.51 T at the center was acquired. The hybrid magnet in this study was developed entirely with domestic technology and the magnetic field of 10.51 T was judged a highest magnetic field in the country.