The spring meeting of the Cryogenic Association of Japan (CA J) was held at Tsukuba Research Centre of Science and Technology Agency at Tsukuba Science City from 16-18 May 1983. Participating were 277 cryogenic scientists and engineers and 126 papers were presented. On the second day, the annual general meeting of CAJ was also held and the Ohyama Prize was given to Professor T. Ogasawara, Professor K. Yasukochi and their group for their work on electromagnetic behaviour of superconducing wire. The details of this and new results presented at the meeting are described in the following.
Superconducting magnet technology. Dynamics of superconducting magnets: It has been recognized that the detection and control of quench phenomena is important and nine papers were presented on this. Three of them concerned acoustic emission (AE) technologies, that is, the relation between the training effect and AE, detection of the quench by AE and the correlation between the strength of AE and the operation mode of the magnet. Dynamic properties of TMC-I (Nb3Sn test module coil of JAERI) were reported in three other papers. Since Nb3Sn has a higher critical temperature, TMC-1 was found to be stable even when the heat flux at the surface of the conductor was larger than the maximum nuclear heat flux. It was also shown that TMC-1 can dump energy at the time constant of 3 s. The strain measurements were also presented. The other papers discussed quench of the magnet cooled by helium II and quench detection of the multiple magnet for the generator.
Superconducting magnets for special purposes: For studies on organic superconducting materials, ETL group developed a rotating superconducting magnet and a cryostat in which samples could be tested at temperatures from 300 to 0.4 K. Tohoku University and Furukawa Electric developed a 13 T magnet for studies on hybrid magnets where the magnet is wound by prereacted Nb3Sn multifilamentary conductor. Another paper described the thin wall solenoid (Venus) magnet of KEK, which was wound with aluminium-stabilized wires. KEK also developed a superconducting magnet without any bobbin in co-operation with Kyushu University and Sumitomo Heavy Industry.
Superconducting magnet design: Six papers were presented at this session. Three of them discussed mainly the structural analysis of fusion magnets. The others presented a calculation method for magnetic fields, the optimum designing method and mechanical problems of the bobbin-less magnet.
Superconducting magnetic energy storage (SMES): Three papers reported the experimental results of pulsive energy transfer circuits, for the purposes of load levelling of dc motors, pulsed superconducting magnets