Design and Demonstration of Al-Stabilized MgB₂ Conductor for Higher-Sensitivity Particle Detection Magnet

To detect the particle energy with high resolution, the trace measurement is important. From this viewpoint, the detector magnets are designed as solenoids with a thinner thickness. What is also needed to maintain a high transparency of the particles is a lower mass of coil constituents. MgB ₂ has great potential not only to reduce mass density of detector magnets but also to simplify cooling systems, which lead to higher transparency of the particles. Focused on the stability of the magnet, the MgB ₂ conductor should be stabilized by various types of Aluminum. To optimize the amount of the stabilizer, we have newly established two-dimensional governing equations for vector field of current diffusion and discretized for performing calculation by finite element method (FEM). The model is based on a demonstration with simplified conductor on which a specific heater attached at the center of the conductor to initiate quench to trigger the current diffusion into the stabilizer. The results show that the residual resistance ratio (RRR) of the stabilizer plays an important rule for current diffusion “depth” indicating optimum amount of Aluminum stabilizer, which would enable us to design thinner conductors for particle-detection magnets with improved robustness.