Transport Characteristics of a Bi-2223 Solenoid Coil in High Magnetic Fields

Transport characteristic of a (Bi, Pb)₂ Sr₂Ca₂Cu₃O₁₀ (Bi-2223) solenoid coil was investigated in liquid helium in high magnetic fields up to 17 T. The solenoid coil was fabricated using the silver sheathed Bi-2223 superconducting tape, which has 2.8 mm in width and 0.32 mm in thickness, including a 0.05-mm-thick copper alloy lamination on both sides. The coil (winding pack) inner diameter, outer diameter, height, and number of turns were 65 mm, 83 mm, 60 mm, and 456 turns, respectively. The coil critical current (I_c) was 28 A at 77 K in self-field. Two noise-canceling coils were set inside and outside of the Bi-2223 coil to reduce the inductive noise. The measurement setup of the noise-canceling coils is similar to that of the magnetization measurement using pick-up coils. Transport measurements were performed at 4.2 K (liquid helium) in the 20-T resistive magnet with 170-mm bore in LNCMI-Grenoble. The coil I_c was 151 A at 17 T, 4.2 K. It was also demonstrated that the noise-canceling coil noticeably reduced the inductive noise by 1/10, which made possible higher resolution voltage measurements.