Superconducting detector magnets for high energy physics

Various superconducting detector solenoids for particle physics have been developed in the world. The key technology is the aluminum-stabilized superconductor for almost all the detector magnets in particle physics experiments. The coil fabrication technology is also important and it has advanced along with the conductor technology, such as the inner coil winding technique, indirect cooling, transparent vacuum vessel, quench protection scheme using pure aluminum strips and so on. The detector solenoids design study is in progress for future big projects in Japan and Europe, that is, ILC (International Linear Collider), FCC (Future Circular Collider) and CLIC (Compact LInear Collider), based on the technologies established over many years. The combination of good mechanical properties and keeping a high RRR is a key point for the development of Al-stabilized conductor. The present concern for the detector solenoid development is to have been nearly losing the key technologies and experiences. Nowadays, there are no industrial companies having the capacity to manufacture such aluminum stabilized superconductor. Complementary efforts are seriously required to re-realize and validate the performance required in the future projects in collaboration with worldwide institutes and industries. Some mid-scale physics experiments required detector solenoids wound with not aluminum stabilized conductor but conventional copper stabilized conductor. The specific requirement is to control the magnetic field distribution precisely, and the efforts to realize the requirement are on going with regard to the magnetic field design technology with high precision simulation, coil fabrication technology and so on.