Competition for the development of compact superconducting SR equipment that could be installed in semiconductor factories began during the latter half of the 1980s. Thereafter, 5 SR units were developed, 4 in Japan and 1 in England. These units are easy to operate and are in practical use. This paper describes the compact superconducting SR unit which authors have developed. Also this paper summarizes and compares the 5 compact superconducting SR units which have been developed and describes the main parameters of the superconducting magnets used therein.
The hybrid magnet, which is a large system composed of an inner water-cooled magnet and an outer superconducting magnet, is well known to be the most suitable for generating steady high-magnetic fields. Thirty T-class hybrid magnets are being operated at several high-magnetic field laboratories, The world's highest steady field at present is 35.2T. Projects to enhance the steady fields up to 40-45T are progressing now at the National Research Institute for Metal, Japan, and the National High Magnetic Field Laboratory, USA. In particular, the NRIM project is just now nearing the final stage. In this article, I review in detail the hybrid magnet technology including those of superconducting magnet and water-cooled magnet, the present status of hybrid magnet systems in operation, and the developing projects at NRIM.