Recent technical trends of superconducting magnets in Japan, part I: Magnet data base and recent progress in magnet winding current density

The committee on applied superconducting apparatuses and characteristics of superconductors, the Institute of Electrical Engineers of Japan (IEEJ) has made a data base on low temperature superconducting magnets which have bee n built over the last ten years in Japan. Based on the data base trends of magnet technology are investigated. In this paper (Part I), out-line of the data base is explained and based on the data base the recent trends of the magnet technology are investigated focusing on sizes and configurations of magnets, current density of magnet windings and conductor configurations. The stability and quench protection of magnets are also investigated in oth er paper (Part II).