An Experimental Study on the Joint Methods Between Double Pancake Coils Using YBCO Coated Conductors

In these days, some researches on the HTS insert coil/LTS background coil (hybrid coil) for nuclear magnetic resonance (NMR) system have been conducted. Magnetic field homogeneity is very important in NMR system. Because the direction of the joint part between a stack of double pancake coils (DPCs) can cause magnetic field homogeneity problem, the joint methods between the DPCs are important. YBCO coated conductor tapes are manufactured in various widths.They can be used as an auxiliary superconducting tape at the joint part between the DPCs for enhancing magnetic field homogeneity. The joint characteristics between the DPCs can vary with the conditions of the auxiliary tape such as numbers, widths, and directions. In this work, we conducted joint experiments under various conditions of the auxiliary tape and analysed the joint characteristics. The joint methods in this work are expected to be used to fabricate an insert coil in NMR system.