Development of Superconducting Magnet for MHD ETL Mark V Facility-Aiming to Establish Technologies for Big High-field Superconducting Magnet-Part II Excitation Failure and Success

摘要

The historic story of the superconducting (SC) magnet for MHD ETL Mark V Facility (cf. Fig. 1) is presented. This SC magnet was developed in the MHD Project (1955 approx 75), which was one of first MITI/AIST Large-Scale R&D Projects and the first national project for superconductor applications in Japan. This SC magnet had been the largest in Japan through 1982 when the Japanese LCT coil was made by JAERI. It was completed after many difficulties, some fatal and some trivial, because of a lack of knowledge, before it could generate maximum magnetic field 7 T with stored energy 65 MJ in 1973. ecause technological problems had piled up and because no management know-how of national projects on technology development had been accumulated before then in the forefront of worldwide technological advances, "step by step" advances and "tial and error" attemps in the progress of the project had to be done over again. The paper is divided into three parts. Part I (Ref.12) described design concept and the conductor tests. In this part II, the failures in exciting the magnet, the repair of the magnet system and the re-challenge with success are described.