Superconducting magnet technology for accelerators

Hitachi, Ltd. has been engaged in the development of superconducting magnets for accelerators while receiving cooperation from other organizations including the Research Institute for High Energy Physics. The present report describes some superconducting magnets recently developed by the company and also outlines major required functions and characteristics, the history of their development, technical features, and study results. Major characteristics of the superconductor designed for each superconducting magnet are summarized first, followed by descriptions of two different magnets developed. One is a saddle-like dipole magnet which is characterized by a small diameter of 40mm, a high current density in the coil of 450A/mm2, and a high load factor of 97 percent. The other is a quadrupole superconducting magnet which is designed for the detection of particles in collision experiments with TRISTAN, a collision type accelerator developed by the Research Institute for High Energy Physics. Hitachi has also developed two superconducting solenoids, CDF (collider detector facility) solenoid and AMY solenoid, which are used for detection. Some features and characteristics of the latter are briefly outlined here. (N.K.)