3T Highly Homogeneous Superconducting Solenoid Approved
On July 29, 2007, the project of Institute of Modern Physics(IMP), Chinese Academy of Sciences(CAS), "3T highly homogeneous superconducting solenoid" was approved officially by a appraisal committee organized by Gansu Provincial Sci. & Tech. Department and Lanzhou Branch of CAS.
After checking the project reports, the test reports by experts and other related technical data sheets and the on-site inspection of the test and operation of the magnet system, the evaluation committee drew the following conclusions
1) The testing method is correct and the measurement results are reliable;
2) The measured central field is 3.0108T, which is better than the design target 3T;
3) The magnetic field homogeneity is ±4.95×10-5, better than the design target ±5×10-5;
4) Through the technique exploration and innovation, the research team has mastered the key technique of the design and fabrication of the low temperature superconducting magnet;
5) The concept design and structure design of the magnet system are correct and the technical route is feasible. The main technology parameters reached the advanced level of the same type homogeneous superconducting solenoid in China.
The main innovations of the project are
1) The size and position of these coils are optimized by using a method combining linear program with multiobjective optimization. The cold iron yoke is used to reduce the stray field and its optimized shape guarantees the high magnetic homogeneity.
2) The superconducting coils and a cold iron yoke are housed in a horizontal room temperature bore, low-loss cryostat, which consist of helium vessel, gas-cooled radiation shield, outer vacuum vessel and low heat loss cold mass supports system.