Design and Performance Estimation of a 20 T 46 mm No-Insulation All-REBCO User Magnet

This paper reports on a proposed design and estimation of performance of a 20 T no-insulation (NI) high temperature superconductor (HTS) standalone user magnet for the National High Magnetic Field Laboratory. It consists of a stack of 18 double pancake coils wound with REBCO tapes from two different vendors, SuNAM and SuperPower, chosen for their complementary in-field critical current, mechanical properties and cost properties. The inner and outer winding diameters and overall height of the magnet are 46 mm, 102.6 mm, and 163.4 mm, respectively. The magnet is designed to generate a 20 T central field at its nominal operating current of 316 A in liquid helium at 4.2 K. The inductance and stored energy are 1.89 H and 94.4 kJ, respectively. In addition to the detailed design parameters, this paper presents a stress analysis, NI charging analysis and post-quench analysis, followed by discussion of design parameters and estimated performance of the proposed 20 T NI HTS magnet.