ミュオンチャネル用大型超電導ソレノイドとその冷却系

抄録

The paper describes the design, construction and long-term perfomances of the 6m-superconducting solenoid and associated supercritical He cooling system for the muon channel of the Meson Science Laboratory, University of Tokyo. The basic new and novel concept of this system compared to the SIN system stays in the following points: 1) the supercritical He is generated by the “Single” heat exchanger located inside the refrigerator cold box, therby simplifying the total cooling system; 2) the iron return yoke is placed at room temperature, reducing substantially the cold weight; 3) after the careful design of the system, a large mass flow of 5.0gr/s is adopted, minimizing cool-down time, etc.
In this report, the emphasis is given for the potential use of this “Simplified” supercritical He cooling for the large-scale superconducting solenoid. Associated design principle as well as required thermodynamical calculations are given.
Through the successful and maintenance free operation in the period of 1980 to 1984 amounting to 9000h, we have confirmed the excellence of the whole system.